UniLA - Developer Guide

By: CS2103-W16-1 Since: Feb 2019 Licence: MIT

1. Setting up
2. Design
3. Implementation
4. Documentation
5. Testing
6. Dev Ops
Appendix A: Suggested Programming Tasks to Get Started
- A.1. Improving each component
- A.2. Creating a new command: remark
Appendix B: Product Scope
Appendix C: User Stories
Appendix D: Use Cases
Appendix E: Non Functional Requirements
Appendix F: Glossary
Appendix G: Product Survey
Appendix H: Instructions for Manual Testing

1. Setting up

1.1. Prerequisites

JDK 9 or later

JDK 10 on Windows will fail to run tests in headless mode due to a JavaFX bug. Windows developers are highly recommended to use JDK 9.
IntelliJ IDE

IntelliJ by default has Gradle and JavaFx plugins installed.
Do not disable them. If you have disabled them, go to File > Settings > Plugins to re-enable them.

1.2. Setting up the project in your computer

Fork this repo, and clone the fork to your computer
Open IntelliJ (if you are not in the welcome screen, click File > Close Project to close the existing project dialog first)
Set up the correct JDK version for Gradle
1. Click Configure > Project Defaults > Project Structure
2. Click New… and find the directory of the JDK
Click Import Project
Locate the build.gradle file and select it. Click OK
Click Open as Project
Click OK to accept the default settings
Open a console and run the command gradlew processResources (Mac/Linux: ./gradlew processResources). It should finish with the BUILD SUCCESSFUL message.
This will generate all resources required by the application and tests.
Open MainWindow.java and check for any code errors
1. Due to an ongoing issue with some of the newer versions of IntelliJ, code errors may be detected even if the project can be built and run successfully
2. To resolve this, place your cursor over any of the code section highlighted in red. Press ALT+ENTER, and select Add '--add-modules=…' to module compiler options for each error
Repeat this for the test folder as well (e.g. check HelpWindowTest.java for code errors, and if so, resolve it the same way)

1.3. Verifying the setup

Run the seedu.address.MainApp and try a few commands
Run the tests to ensure they all pass.

1.4. Configurations to do before writing code

1.4.1. Configuring the coding style

This project follows oss-generic coding standards. IntelliJ’s default style is mostly compliant with ours but it uses a different import order from ours. To rectify,

Go to File > Settings… (Windows/Linux), or IntelliJ IDEA > Preferences… (macOS)
Select Editor > Code Style > Java
Click on the Imports tab to set the order
- For Class count to use import with '*' and Names count to use static import with '*': Set to 999 to prevent IntelliJ from contracting the import statements
- For Import Layout: The order is import static all other imports, import java.*, import javax.*, import org.*, import com.*, import all other imports. Add a <blank line> between each import

Optionally, you can follow the UsingCheckstyle.adoc document to configure Intellij to check style-compliance as you write code.

1.4.2. Updating documentation to match your fork

After forking the repo, the documentation will still have the SE-EDU branding and refer to the se-edu/addressbook-level4 repo.

If you plan to develop this fork as a separate product (i.e. instead of contributing to se-edu/addressbook-level4), you should do the following:

Configure the site-wide documentation settings in build.gradle, such as the site-name, to suit your own project.
Replace the URL in the attribute repoURL in DeveloperGuide.adoc and UserGuide.adoc with the URL of your fork.

1.4.3. Setting up CI

Set up Travis to perform Continuous Integration (CI) for your fork. See UsingTravis.adoc to learn how to set it up.

After setting up Travis, you can optionally set up coverage reporting for your team fork (see UsingCoveralls.adoc).

Coverage reporting could be useful for a team repository that hosts the final version but it is not that useful for your personal fork.

Optionally, you can set up AppVeyor as a second CI (see UsingAppVeyor.adoc).

Having both Travis and AppVeyor ensures your App works on both Unix-based platforms and Windows-based platforms (Travis is Unix-based and AppVeyor is Windows-based)

1.4.4. Getting started with coding

When you are ready to start coding,

Get some sense of the overall design by reading Section 2.1, “Architecture”.
Take a look at Appendix A, Suggested Programming Tasks to Get Started.

2. Design

2.1. Architecture

Figure 1. Architecture Diagram

The Architecture Diagram given above explains the high-level design of the App. Given below is a quick overview of each component.

The .pptx files used to create diagrams in this document can be found in the diagrams folder. To update a diagram, modify the diagram in the pptx file, select the objects of the diagram, and choose Save as picture.

Main has only one class called MainApp. It is responsible for,

At app launch: Initializes the components in the correct sequence, and connects them up with each other.
At shut down: Shuts down the components and invokes cleanup method where necessary.

Commons represents a collection of classes used by multiple other components. The following class plays an important role at the architecture level:

LogsCenter : Used by many classes to write log messages to the App’s log file.

The rest of the App consists of four components.

UI: The UI of the App.
Logic: The command executor.
Model: Holds the data of the App in-memory.
Storage: Reads data from, and writes data to, the hard disk.

Each of the four components

Defines its API in an interface with the same name as the Component.
Exposes its functionality using a {Component Name}Manager class.

For example, the Logic component (see the class diagram given below) defines it’s API in the Logic.java interface and exposes its functionality using the LogicManager.java class.

Figure 2. Class Diagram of the Logic Component

How the architecture components interact with each other

The Sequence Diagram below shows how the components interact with each other for the scenario where the user issues the command delete 1.

Figure 3. Component interactions for delete 1 command

The sections below give more details of each component.

2.2. UI component

Figure 4. Structure of the UI Component

API : Ui.java

The UI consists of a MainWindow that is made up of parts e.g.CommandBox, ResultDisplay, PersonListPanel, StatusBarFooter, BrowserPanel etc. All these, including the MainWindow, inherit from the abstract UiPart class.

The UI component uses JavaFx UI framework. The layout of these UI parts are defined in matching .fxml files that are in the src/main/resources/view folder. For example, the layout of the MainWindow is specified in MainWindow.fxml

The UI component,

Executes user commands using the Logic component.
Listens for changes to Model data so that the UI can be updated with the modified data.

2.3. Logic component

Figure 5. Structure of the Logic Component

API : Logic.java

Logic uses the AddressBookParser class to parse the user command.
This results in a Command object which is executed by the LogicManager.
The command execution can affect the Model (e.g. adding a person).
The result of the command execution is encapsulated as a CommandResult object which is passed back to the Ui.
In addition, the CommandResult object can also instruct the Ui to perform certain actions, such as displaying help to the user.

Given below is the Sequence Diagram for interactions within the Logic component for the execute("delete 1") API call.

Figure 6. Interactions Inside the Logic Component for the delete 1 Command

2.4. Model component

Figure 7. Structure of the Model Component

API : Model.java

The Model,

stores a UserPref object that represents the user’s preferences.
stores the UniLA data.
exposes an unmodifiable ObservableList<Person> that can be 'observed' e.g. the UI can be bound to this list so that the UI automatically updates when the data in the list change.
does not depend on any of the other three components.

As a more OOP model, we can store a Tag list in Address Book, which Person can reference. This would allow Address Book to only require one Tag object per unique Tag, instead of each Person needing their own Tag object. An example of how such a model may look like is given below.

2.5. Storage component

Figure 8. Structure of the Storage Component

API : Storage.java

The Storage component,

can save UserPref objects in json format and read it back.
can save the UniLA data in json format and read it back.

2.6. Common classes

Classes used by multiple components are in the seedu.addressbook.commons package.

3. Implementation

This section describes some noteworthy details on how certain features are implemented.

3.1. Import Contacts

3.1.1. Current Implementation

The ImportCommand uses JsonAddressBookStorage to create a temporary AddressBook instance from a given path. It takes in a Path path as argument. The command will add the contacts, events and reminders found in this temporary AddressBook but not present in the AddressBook storage into storage. The constructor for ImportCommand is as follows:

 public ImportCommand(Path importPath) {
        requireNonNull(importPath);
        this.filePath = importPath;
        addressBookStorage = new JsonAddressBookStorage(filePath);
 }

The execution flow of ImportCommand is shown in the diagram below.

Figure: Import command flow chart

3.1.2. Design Considerations

Aspects : Implementation Import Command

Alternative 1 (current choice): Users import contacts, events and reminders from one .json file.
- Pros: This approach minimizes the effort needed from users to import data.
- Cons: Users might want to separate contacts, events and reminders so that importing one component will not affect the other
Alternative 2: Users import contacts, events and reminders from separate files.
- Pros: Data can be imported independently.
- Cons: It takes unnecessary extra effort to import data separately.

3.2. Export

3.2.1. Current Implementation

The ExportCommand uses JsonAddressBookStorage class to generate a .json file storing contacts, events and reminders by specified tags to store at a specified path. It takes in a String name, Path path and an optional Tag tag. Omitting the tag will simply save all data into the json file. Below is the main idea ExportCommand constructor:

public ExportCommand(String fileName, Path exportPath, Tag tagExport) {
        requireNonNull(exportPath);
        this.filePath = exportPath;
        this.fileName = fileName;
        this.tag = tagExport;
        this.addressBookExported = new AddressBook();
        addressBookStorage = new JsonAddressBookStorage(filePath);
    }

The execution flow of the Export command is shown below.

Figure: Export command flow chart

Either zero or one tag can be specified. Therefore below are the possible scenarios:

Without a tag
- The app exports all contacts, events and reminders in the UniLA by default.
With a Tag
- The app exports all contacts bearing the specified tag in their tagset, along with all events and reminders.

The final step is to create the xml/excel file from the teachConnectBook. This is done with the help of the method tryStorage().

3.2.2. Design Considerations

Aspects : Implementation Export Command

Alternative 1: Users can export contacts, events, reminders into separate files.
- Pros: This implementation removes the dependency between contacts, events and reminders. Users can change one component without affecting the other.
- Cons: It might take more effort from users to import and export data in general because they need to handle each component separately.
Alternative 2 (current choice): Users export all data into the same file.
- Pros: This implementation helps remove the need for importing contacts, events and reminders separately. Instead everything can be imported at once.
- Cons: Contacts, events and reminders are exported together, and thus there is codependency between these components.

3.3. Undo/Redo feature

3.3.1. Current Implementation

The undo/redo mechanism is facilitated by VersionedAddressBook. It extends AddressBook with an undo/redo history, stored internally as an addressBookStateList and currentStatePointer. Additionally, it implements the following operations:

VersionedAddressBook#commit() — Saves the current address book state in its history.
VersionedAddressBook#undo() — Restores the previous address book state from its history.
VersionedAddressBook#redo() — Restores a previously undone address book state from its history.

These operations are exposed in the Model interface as Model#commitAddressBook(), Model#undoAddressBook() and Model#redoAddressBook() respectively.

Given below is an example usage scenario and how the undo/redo mechanism behaves at each step.

Step 1. The user launches the application for the first time. The VersionedAddressBook will be initialized with the initial address book state, and the currentStatePointer pointing to that single address book state.

Step 2. The user executes delete 5 command to delete the 5th person in the UniLA. The delete command calls Model#commitAddressBook(), causing the modified state of the address book after the delete 5 command executes to be saved in the addressBookStateList, and the currentStatePointer is shifted to the newly inserted address book state.

Step 3. The user executes add n/David … to add a new person. The add command also calls Model#commitAddressBook(), causing another modified address book state to be saved into the addressBookStateList.

If a command fails its execution, it will not call Model#commitAddressBook(), so the address book state will not be saved into the addressBookStateList.

Step 4. The user now decides that adding the person was a mistake, and decides to undo that action by executing the undo command. The undo command will call Model#undoAddressBook(), which will shift the currentStatePointer once to the left, pointing it to the previous address book state, and restores the address book to that state.

If the currentStatePointer is at index 0, pointing to the initial address book state, then there are no previous address book states to restore. The undo command uses Model#canUndoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the undo.

The following sequence diagram shows how the undo operation works:

The redo command does the opposite — it calls Model#redoAddressBook(), which shifts the currentStatePointer once to the right, pointing to the previously undone state, and restores the address book to that state.

If the currentStatePointer is at index addressBookStateList.size() - 1, pointing to the latest address book state, then there are no undone address book states to restore. The redo command uses Model#canRedoAddressBook() to check if this is the case. If so, it will return an error to the user rather than attempting to perform the redo.

Step 5. The user then decides to execute the command list. Commands that do not modify the address book, such as list, will usually not call Model#commitAddressBook(), Model#undoAddressBook() or Model#redoAddressBook(). Thus, the addressBookStateList remains unchanged.

Step 6. The user executes clear, which calls Model#commitAddressBook(). Since the currentStatePointer is not pointing at the end of the addressBookStateList, all address book states after the currentStatePointer will be purged. We designed it this way because it no longer makes sense to redo the add n/David … command. This is the behavior that most modern desktop applications follow.

The following activity diagram summarizes what happens when a user executes a new command:

3.3.2. Design Considerations

Aspect: How undo & redo executes

Alternative 1 (current choice): Saves the entire address book.
- Pros: Easy to implement.
- Cons: May have performance issues in terms of memory usage.
Alternative 2: Individual command knows how to undo/redo by itself.
- Pros: Will use less memory (e.g. for delete, just save the person being deleted).
- Cons: We must ensure that the implementation of each individual command are correct.

Aspect: Data structure to support the undo/redo commands

Alternative 1 (current choice): Use a list to store the history of address book states.
- Pros: Easy for new Computer Science student undergraduates to understand, who are likely to be the new incoming developers of our project.
- Cons: Logic is duplicated twice. For example, when a new command is executed, we must remember to update both HistoryManager and VersionedAddressBook.
Alternative 2: Use HistoryManager for undo/redo
- Pros: We do not need to maintain a separate list, and just reuse what is already in the codebase.
- Cons: Requires dealing with commands that have already been undone: We must remember to skip these commands. Violates Single Responsibility Principle and Separation of Concerns as HistoryManager now needs to do two different things.

3.4. Find feature

3.4.1. Current Implementation

The mechanism is facilitated by findCommand, findCommandParser and different Predicate classes. It allows users to search with 3 different search patterns. During the execution of find command, 3 search patterns will be executed one by one.

Given below is the process of executing find command:

Step 1. The exact search: This is a base method of matching string. It’s implemented by String.equals().

Step 2. The fuzzy search: This is based on similarity comparison. First edit distance between input keywords and the string in people’s fields is calculated based on Levenshtein Distance algorithm. Subsequently, similarity is calculated by s = 1 - Levenshtein_Distance/Max_Length_Of_Two_Strings. The similarity threshold is set to 0.7. If a person’s fields contain keyword which have more than 0.7 similarity to the input keywords, he or she will be returned in fuzzy search result.

Step 3. The wildcard search: This is based on regular expression. It recognizes character *. The character * matches any number of alphanumeric characters consisting of 0-9, a-z and A-Z.

The following code snippet is from TagsContainsKeywordPredicate class. It shows an example of how predicate class works:

    @Override
    public boolean test(Person person) {
        return keywords.stream()
                .anyMatch(keyword -> {
                    String name = person.getName().fullName;
                    String tags = person.getTagsAsStringNoBracket();
                    if (StringUtil.containsWordIgnoreCase(tags, keyword)) {
                        if (!exactSearchList.contains(name)) {
                            exactSearchList.add(name);
                        }
                        return true;
                    }
                    if (StringUtil.matchFuzzySearch(tags, keyword)) {
                        if (!fuzzySearchList.contains(name)) {
                            fuzzySearchList.add(name);
                       }
                        return true;
                    }
                    if (StringUtil.matchWildcardSearch(tags, keyword)) {
                        if (!wildcardSearchList.contains(name)) {
                            wildcardSearchList.add(name);
                        }
                        return true;
                    }
                    return false;
                });
    }

3.4.2. Design Considerations

Aspect: How fuzzy search is executed

Alternative 1 (current choice): Use similarity to compare the keywords
- Pros: The accuracy is higher because the differences and the total length of the strings are proportional.
- Cons: Less easy to implement.
Alternative 2: Use edit distance to compare the keywords
- Pros: Easy to implement.
- Cons: Lower accuracy especially when the string is short.

Different search patterns optimize the 'find' command for different kinds of users. They help with users when they cannot remember the exact spelling or users who are prone to typos.

3.5. Photo feature

3.5.1. Current Implementation

The mechanism is facilitated by Photo, PhotoCommand class. A Photo class is added to Model. It allows users to add a photo to the person in the contact list.

Given below is the process of executing photo command:

Step 1. The command will be checked whether it contains sub command clear. If it is a photo clear command, the photo of the contact list will reset to default photo. The photo command execution is finished. Else, following steps will be executed.

Step 2. The input file path will be checked for whether the file exists.

Step 3. The input file path will be checked for whether it can be opened as an image.

Step 4. The size the of photo will be checked for whether it is within the range (smaller than 20MB).

Step 5. The photo will be copied to the program and it is saved to the target person.

The following code snippet is from PhotoCommand class. It shows an example of how photo command executes:

if (photo.getPath().equals(COMMAND_SUB)) {
    photo.setPath(DEFAULT_PHOTOPATH);
    Person personToEdit = lastShownList.get(targetIndex.getZeroBased());
    String path = personToEdit.getPhoto().getPath();
    File file = new File(path);
    file.delete();

    } else {
    if (!isValidPhotoPath(photo.getPath())) {
         return new CommandResult(MESSAGE_INVALID_PHOTOPATH);
    }
    if (!isImage(photo.getPath())) {
         return new CommandResult(MESSAGE_FILE_NOT_IMAGE);
    }
    if (!isPhotoSizeWithinRange(photo.getPath())) {
         return new CommandResult(MESSAGE_SIZE_EXCEED);
    }

    String user = System.getProperty("user.name");
    String dir = "data/";
    String copyPath = FileUtil.copyFile(photo.getPath(), String.format(dir, user));
    photo.setPath(copyPath);
    }

3.5.2. Design Considerations

Aspect: How photo is stored in UniLA

Alternative 1 (current choice): Copy the photo to the program.
- Pros: The address book will not be affected if the photo in the original path is moved, renamed or deleted. Stability of the program is ensured.
- Cons: Consumes more memory because the photo is copied to the program.
Alternative 2: Save the path and load the photo from the path every time when user opens the app.
- Pros: Use less memory. Easy to implement.
- Cons: The photo will be not be displayed if the photo in the original path is moved, renamed or deleted.

3.6. Event list component

3.6.1. Current Implementation

The Event list component complements Person list(the original addressbook4) to provide user with better manage events and their participants. To achieve this, a new Event model is created to according to the below class diagram.

All the Events object will be stored inside UniqueEventList, which becomes another data collection inside AddressBook class. When ModelManager create VersionedAddressBook(implements AddressBook), there will be two data collections, one for event and the other for contact. From the below Model class diagram, it will be easier to see the illustrate how this Event model integrate the original data structures

Several use cases are implemented for this event components, the use case diagram is shown below:

3.6.2. Design Considerations

Aspect: How to implement Event list component

Alternative 1 (current choice): Add UniqueEventList into AddressBook.
- Pros: Easy to implement and current redo, undo, clear command can work for this Event model commands
- Cons: AddressBook need to manage both contacts and events, thus have to implement more functions, like add, delete, set for both event and person.
Alternative 2: Build another class outside AddressBook to maintain UniqueEventList
- Pros: Functionality will be separated to different classes.
- Cons: This will need much more implementation to build the event list component, including VersionedAddressBook, redo,undo

3.7. Connect feature

3.7.1. Current Implementation

The connect feature will provide two commands, Connect and Disconnect, which is used to add/remove a person to an event as participants. The connect/disconnect mechanism is facilitated by the persons list attribute defined in Event class. All the participants for an event is stored inside the persons list. The connect/disconnect functions are achieved by adding/removing person from the list in a specific event. To achieve this function and other person-event related functions, a unidirectional reference is maintained from Event to Person, as shown below.

3.7.2. Design Considerations

Aspect: How to implement Connection between contact and event

Alternative 1 (current choice): Maintain unidirectional relationship between events and contacts.
- Pros: Easier to implement, sufficient for all the operations provided in the current product and less memory/storage required
- Cons: meet function need to loop through all events to plan a meeting
Alternative 2: Maintain bidirectional relationship between events and contacts.
- Pros: Still easy to implement, easier to get the events that each person has.
- Cons: This bidirectional relationship is relatively harder to manage than unidirectional, because delete person/event and connect/disconnect need to change both two referencing lists. Also, more storage will be used in this implementation because Person class also maintain all the Events it is participating, although when the number of events and persons is small, the difference in storage is not significant.

3.8. Meeting Planner

The mechanism is supported by the MeetCommand class. This command allows users to automatically create a meeting event among certain people, removing the need to siphon through all the events just to find a common available timeslot among contacts to meet. The command will:

search for the earliest available timeslot among the requested people to meet
create the meeting event in the event list
connect the requested people to the event and
set the details of the event (such as name, description etc.) as requested.

Format: meet INDEX TAGS n/NAME d/DESCRIPTION v/VENUE l/LABEL duration/DURATION s/STARTDATETIME e/ENDDATETIME block/BLOCK

Example:

meet 1 2 t/friends t/colleagues n/Snooker competition d/Playing snooker again v/SAFRA Toa Payoh l/snooker duration/0 8 -30 0 s/2019-05-01 00:00:00 e/2019-05-07 00:00:00 block/09:00 18:00

creates an event whereby:

The event will have the first and second people in the contact list, and all persons with the friends or colleagues tag, or both
The event’s name is Snooker competition
The event’s description is Playing snooker again
The event venue is SAFRA Toa Payoh
The event is labeled as snooker
The event will last 7 hours and 30 minutes
The event will start at or after 1st May 2019 at 12am
The event will end at or before 7th May 2019 at 12am
The event must fall within 9am to 6pm of the same day.

3.8.1. How it works:

MeetCommandParser parses meet command. The MeetCommandParser will ensure that:
- at least one index or tag was entered
- all indices are valid
- all other errors caused by invalid arguments will be thrown by ParserUtil and ParserUtilForEvent
All the fields are passed as arguments into the constructor of MeetCommand, which stores all arguments as instance fields.
MeetCommand retrieves the specified persons from model. If a person is not able to be retrieved from the contact list, or if it discovers that less than two valid persons were entered, a CommandException is thrown.
Next, a check will be done to ensure that the specified start time entered is non-trivial, that is, the earliest event created must start at least from the next hour from the time the user enters the command. If the user enters a date and time before the date and time when the command is entered, the next hour after the current date and time will be used instead.
The full event list will be retrieved from model, and piped into a Stream.
Events will be filtered off from the Stream, based on whether the event involves any of the people specified by the user. This is so that a common free slot can be found.
The events will then be sorted in order of start time, so that the earliest available common free time slot can be found.
The earliest common time slot that fits the given block and duration of the event is searched for.
This event is created, added, and the addressbook is then committed.

The sequence of interactions is shown in the following diagram:

The loop portion is not actually implemented with a for or while loop. Instead, a Stream was used as it was able to filter and reduce each event sequentially.

The following describes the logic behind points 4 till 9.

Suppose the user enters meet 1 2 3 s/2019-05-14 03:00 duration/0 4 0 0 block/09:30 18:00. In this case, the indices, tags, name, description, venue and label are trivial to the logic. Further suppose the user enters this command at some date and time before 03:00 on 14 May 2019.

In this user’s current events list, there are six events, all involving either persons 1, 2 or 3. These events are "in the way". They are depicted as red boxes in the following diagrams. All other events in the list have been filtered away by the Stream.

The yellow region signifies the block entered by the user, i.e. the block of time which the event must fall in.

Because the start time is after the next hour from the time the command was entered, an event with a duration of 4 hours that starts on 3am on 14 May 2019 is created. This is labeled as meeting in light blue below.

meeting is first transformed to fit in the first block. This is done by the transformEventToFitBlock(Event e) method.

At this point, all existing events in the events list (shown in red) will be piped into a Stream object. This stream is filtered, such that all events that do not have any of the proposed meeting participants are filtered out.

In this case, because all events in the user’s events list involve either persons 1, 2 or 3, none of them are filtered out. Now, reduce is applied on this Stream object.

The following is the code snippet for the reduce method.

.reduce(meeting, (x, y) -> {
    LocalDateTime xEnd = toDateTime(x.getEndDateTime());
    LocalDateTime yStart = toDateTime(y.getStartDateTime());
    LocalDateTime yEnd = toDateTime(y.getEndDateTime());
    if (toDateTime(x.getStartDateTime()).isAfter(yEnd)
            || !xEnd.isAfter(yStart)) {
        return x;

    }
    LocalDateTime start = yEnd;
    return transformEventToFitBlock(new Event(name, description, venue,
            new DateTime(start.format(DateTime.DATE_TIME_FORMATTER)),
            new DateTime(start.plus(duration).format(DateTime.DATE_TIME_FORMATTER)), label));
});

In this case, x will always be the meeting event, shown in blue. Event y will be highlighted green.

Because the stream has already been sorted in order of start DateTime s, y will be selected in order of left to right in the diagram.

The logic behind reduce is as follows:

If x does not clash with y, then (x, y) reduces to x.
Else, create a new meeting that starts at the end DateTime of y, then transform it to fit the block.

Pictorially, it will look like the following.

The left-most event is selected as y. In the first use of reduce, the identity was set to be the initial meeting:Event, in blue.

Because the event in blue does not clash with the event in green, both events simply reduce to the one in blue. The next left-most event is selected as the next y.

In this case, the event in blue clashes with the event in green. Thus, a new event, with a duration of 4 hours (same as before), that starts at the end of y, is created. This event is then transformed to fit the block, which in this case already does. The old blue and green events are reduced to this new event.

Here, the event in blue clashes with the event in green. A new event with a duration of 4 hours, that starts at the end of y, is created. This event is then transformed to fit the block, in this case, it is pushed all the way to start at 09:30 the next day.

The event here does not clash with meeting. Both events reduce to meeting.

Here, the event in blue clashes with the event in green. Just as before, the two old events are reduced to a new meeting event that starts right after the end of y and is within the block.

Finally, the last event does not clash with the event in blue. Both events reduce to the event in blue.

This event is then tested whether its end DateTime is later than the latest end DateTime specified by the user, and whether there are duplicate events. I would have written a lot more, but I’m out of space in my PPP.

3.9. Reminder Component

The mechanism is supported by the reminder and reminderList class. It allows users to add reminders to event, which will pop in app certain interval before event start time. Please refer to this class diagram.

reminderList will keep track of all reminder. reminder class contains Unit, Interval to facilitate the constructor building. Please refer to the following class diagram.

3.9.1. Aspect: How to implement `reminder`

Alternative 1 (current choice): Create new model, named reminder to include reminder and reminderList class.
- Pros: Convenient for modifying because of the relatively loose connection with event.
- Cons: Require large change in model.
Alternative 2: Add another attribute named reminder to record the remind time and we can list the event by sorting remind time.
- Pros: Easy to implement. Only need event and person model.
- Cons: Not easy to delete corresponding reminder after its reminding time as it is highly connected with event. Cannot be applied and modified anywhere.

3.9.2. Aspect: How to implement `reminderList`

Alternative 1 (current choice): Create only one reminder list for whole UniLA.
- Pros: Convenient for adding, deleting, and checking.
- Cons: Required more connection between logic and model.
Alternative 2: Create one reminder list for each event for whole UniLA.
- Pros: Easy to implement.
- Cons: Not centered. Need to loop through every event when add, delete and check.

3.10. Reminder Feature

Please take a look at use case diagram first.

Among these features, the addR combined with reminderCheck is the most useful one. The mechanism is supported by ReminderCheck,AddR and AddR parser classes. It allows users to create a reminder in certain interval before event start time. And the reminder will pop inside app at that reminding time. Also, it will disappear after showing up for one minute.

Given below is an example usage scenario and how the AddR reminder behaves.

Step 1. The user lists events in address and select the event that the user wants UniLA to remind.

Step 2. User run command addR 2 t/4 u/min, which will let UniLA add the one 4min-before-starttime reminder to the second event.

Step 3. When the time is up, the reminder pop up under listR model.

Step 4. After showing up for 1 minute, the reminder will be automatically deleted from the reminder list.

3.10.1. How it works:

AddRCommandParser parses addR command. The AddRCommandParser will ensure the interval unit and to check possible exceptions.
Interval and event will be passed to AddRCommand. AddRCommand touched model to create new reminder in reminder list.
Another thread named reminderCheck will be running at the same time. It will check when to pop up the reminder, and when to make it disappear by comparing the starting time - interval with current time.
Reminder which satisfies the time requirement will pop up under listR model.
Reminder will be deleted from reminder list after it shows up for 1 minute.

To achieve the reminder check function, another thread is created as the sequence diagram shown below.

3.11. Logging

We are using java.util.logging package for logging. The LogsCenter class is used to manage the logging levels and logging destinations.

The logging level can be controlled using the logLevel setting in the configuration file (See Section 3.12, “Configuration”)
The Logger for a class can be obtained using LogsCenter.getLogger(Class) which will log messages according to the specified logging level
Currently log messages are output through: Console and to a .log file.

Logging Levels

SEVERE : Critical problem detected which may possibly cause the termination of the application
WARNING : Can continue, but with caution
INFO : Information showing the noteworthy actions by the App
FINE : Details that is not usually noteworthy but may be useful in debugging e.g. print the actual list instead of just its size

3.12. Configuration

Certain properties of the application can be controlled (e.g user prefs file location, logging level) through the configuration file (default: config.json).

4. Documentation

We use asciidoc for writing documentation.

We chose asciidoc over Markdown because asciidoc, although a bit more complex than Markdown, provides more flexibility in formatting.

4.1. Editing Documentation

See UsingGradle.adoc to learn how to render .adoc files locally to preview the end result of your edits. Alternatively, you can download the AsciiDoc plugin for IntelliJ, which allows you to preview the changes you have made to your .adoc files in real-time.

4.2. Publishing Documentation

See UsingTravis.adoc to learn how to deploy GitHub Pages using Travis.

4.3. Converting Documentation to PDF format

We use Google Chrome for converting documentation to PDF format, as Chrome’s PDF engine preserves hyperlinks used in webpages.

Here are the steps to convert the project documentation files to PDF format.

Follow the instructions in UsingGradle.adoc to convert the AsciiDoc files in the docs/ directory to HTML format.
Go to your generated HTML files in the build/docs folder, right click on them and select Open with → Google Chrome.
Within Chrome, click on the Print option in Chrome’s menu.
Set the destination to Save as PDF, then click Save to save a copy of the file in PDF format. For best results, use the settings indicated in the screenshot below.

Figure 9. Saving documentation as PDF files in Chrome

4.4. Site-wide Documentation Settings

The build.gradle file specifies some project-specific asciidoc attributes which affects how all documentation files within this project are rendered.

Attributes left unset in the build.gradle file will use their default value, if any.

Table 1. List of site-wide attributes
Attribute name	Description	Default value
`site-name`	The name of the website. If set, the name will be displayed near the top of the page.	not set
`site-githuburl`	URL to the site’s repository on GitHub. Setting this will add a "View on GitHub" link in the navigation bar.	not set
`site-seedu`	Define this attribute if the project is an official SE-EDU project. This will render the SE-EDU navigation bar at the top of the page, and add some SE-EDU-specific navigation items.	not set

4.5. Per-file Documentation Settings

Each .adoc file may also specify some file-specific asciidoc attributes which affects how the file is rendered.

Asciidoctor’s built-in attributes may be specified and used as well.

Attributes left unset in .adoc files will use their default value, if any.

Table 2. List of per-file attributes, excluding Asciidoctor’s built-in attributes
Attribute name	Description	Default value
`site-section`	Site section that the document belongs to. This will cause the associated item in the navigation bar to be highlighted. One of: `UserGuide`, `DeveloperGuide`, `LearningOutcomes`, `AboutUs`, `ContactUs` Official SE-EDU projects only	not set
`no-site-header`	Set this attribute to remove the site navigation bar.	not set

4.6. Site Template

The files in docs/stylesheets are the CSS stylesheets of the site. You can modify them to change some properties of the site’s design.

The files in docs/templates controls the rendering of .adoc files into HTML5. These template files are written in a mixture of Ruby and Slim.

Modifying the template files in docs/templates requires some knowledge and experience with Ruby and Asciidoctor’s API. You should only modify them if you need greater control over the site’s layout than what stylesheets can provide. The SE-EDU team does not provide support for modified template files.

5. Testing

5.1. Running Tests

There are three ways to run tests.

The most reliable way to run tests is the 3rd one. The first two methods might fail some GUI tests due to platform/resolution-specific idiosyncrasies.

Method 1: Using IntelliJ JUnit test runner

To run all tests, right-click on the src/test/java folder and choose Run 'All Tests'
To run a subset of tests, you can right-click on a test package, test class, or a test and choose Run 'ABC'

Method 2: Using Gradle

Open a console and run the command gradlew clean allTests (Mac/Linux: ./gradlew clean allTests)

See UsingGradle.adoc for more info on how to run tests using Gradle.

Method 3: Using Gradle (headless)

Thanks to the TestFX library we use, our GUI tests can be run in the headless mode. In the headless mode, GUI tests do not show up on the screen. That means the developer can do other things on the Computer while the tests are running.

To run tests in headless mode, open a console and run the command gradlew clean headless allTests (Mac/Linux: ./gradlew clean headless allTests)

5.2. Types of tests

We have two types of tests:

GUI Tests - These are tests involving the GUI. They include,
1. System Tests that test the entire App by simulating user actions on the GUI. These are in the systemtests package.
2. Unit tests that test the individual components. These are in seedu.address.ui package.
Non-GUI Tests - These are tests not involving the GUI. They include,
1. Unit tests targeting the lowest level methods/classes.
  e.g. seedu.address.commons.StringUtilTest
2. Integration tests that are checking the integration of multiple code units (those code units are assumed to be working).
  e.g. seedu.address.storage.StorageManagerTest
3. Hybrids of unit and integration tests. These test are checking multiple code units as well as how the are connected together.
  e.g. seedu.address.logic.LogicManagerTest

5.3. Troubleshooting Testing

Problem: HelpWindowTest fails with a NullPointerException.

Reason: One of its dependencies, HelpWindow.html in src/main/resources/docs is missing.
Solution: Execute Gradle task processResources.

6. Dev Ops

6.1. Build Automation

See UsingGradle.adoc to learn how to use Gradle for build automation.

6.2. Continuous Integration

We use Travis CI and AppVeyor to perform Continuous Integration on our projects. See UsingTravis.adoc and UsingAppVeyor.adoc for more details.

6.3. Coverage Reporting

We use Coveralls to track the code coverage of our projects. See UsingCoveralls.adoc for more details.

6.4. Documentation Previews

When a pull request has changes to asciidoc files, you can use Netlify to see a preview of how the HTML version of those asciidoc files will look like when the pull request is merged. See UsingNetlify.adoc for more details.

6.5. Making a Release

Here are the steps to create a new release.

Update the version number in MainApp.java.
Generate a JAR file using Gradle.
Tag the repo with the version number. e.g. v0.1
Create a new release using GitHub and upload the JAR file you created.

6.6. Managing Dependencies

A project often depends on third-party libraries. For example, Address Book depends on the Jackson library for JSON parsing. Managing these dependencies can be automated using Gradle. For example, Gradle can download the dependencies automatically, which is better than these alternatives:

Include those libraries in the repo (this bloats the repo size)
Require developers to download those libraries manually (this creates extra work for developers)

Appendix A: Suggested Programming Tasks to Get Started

Suggested path for new programmers:

First, add small local-impact (i.e. the impact of the change does not go beyond the component) enhancements to one component at a time. Some suggestions are given in Section A.1, “Improving each component”.
Next, add a feature that touches multiple components to learn how to implement an end-to-end feature across all components. Section A.2, “Creating a new command: remark” explains how to go about adding such a feature.

A.1. Improving each component

Each individual exercise in this section is component-based (i.e. you would not need to modify the other components to get it to work).

`Logic` component

Scenario: You are in charge of logic. During dog-fooding, your team realize that it is troublesome for the user to type the whole command in order to execute a command. Your team devise some strategies to help cut down the amount of typing necessary, and one of the suggestions was to implement aliases for the command words. Your job is to implement such aliases.

Do take a look at Section 2.3, “Logic component” before attempting to modify the Logic component.

Add a shorthand equivalent alias for each of the individual commands. For example, besides typing clear, the user can also type c to remove all persons in the list.
- Hints
  
  Just like we store each individual command word constant COMMAND_WORD inside *Command.java (e.g. FindCommand#COMMAND_WORD, DeleteCommand#COMMAND_WORD), you need a new constant for aliases as well (e.g. FindCommand#COMMAND_ALIAS).
  
  AddressBookParser is responsible for analyzing command words.
- Solution
  
  Modify the switch statement in AddressBookParser#parseCommand(String) such that both the proper command word and alias can be used to execute the same intended command.
  
  Add new tests for each of the aliases that you have added.
  
  Update the user guide to document the new aliases.
  
  See this PR for the full solution.

`Model` component

Scenario: You are in charge of model. One day, the logic-in-charge approaches you for help. He wants to implement a command such that the user is able to remove a particular tag from everyone in the UniLA, but the model API does not support such a functionality at the moment. Your job is to implement an API method, so that your teammate can use your API to implement his command.

Do take a look at Section 2.4, “Model component” before attempting to modify the Model component.

Add a removeTag(Tag) method. The specified tag will be removed from everyone in the UniLA.
- Hints
  
  The Model and the AddressBook API need to be updated.
  
  Think about how you can use SLAP to design the method. Where should we place the main logic of deleting tags?
  
  Find out which of the existing API methods in AddressBook and Person classes can be used to implement the tag removal logic. AddressBook allows you to update a person, and Person allows you to update the tags.
- Solution
  
  Implement a removeTag(Tag) method in AddressBook. Loop through each person, and remove the tag from each person.
  
  Add a new API method deleteTag(Tag) in ModelManager. Your ModelManager should call AddressBook#removeTag(Tag).
  
  Add new tests for each of the new public methods that you have added.
  
  See this PR for the full solution.

`Ui` component

Scenario: You are in charge of ui. During a beta testing session, your team is observing how the users use your UniLA application. You realize that one of the users occasionally tries to delete non-existent tags from a contact, because the tags all look the same visually, and the user got confused. Another user made a typing mistake in his command, but did not realize he had done so because the error message wasn’t prominent enough. A third user keeps scrolling down the list, because he keeps forgetting the index of the last person in the list. Your job is to implement improvements to the UI to solve all these problems.

Do take a look at Section 2.2, “UI component” before attempting to modify the UI component.

Use different colors for different tags inside person cards. For example, friends tags can be all in brown, and colleagues tags can be all in yellow.

Before

After
- Hints
  
  The tag labels are created inside the PersonCard constructor (new Label(tag.tagName)). JavaFX’s Label class allows you to modify the style of each Label, such as changing its color.
  
  Use the .css attribute -fx-background-color to add a color.
  
  You may wish to modify DarkTheme.css to include some pre-defined colors using css, especially if you have experience with web-based css.
- Solution
  
  You can modify the existing test methods for PersonCard 's to include testing the tag’s color as well.
  
  See this PR for the full solution.
  
  The PR uses the hash code of the tag names to generate a color. This is deliberately designed to ensure consistent colors each time the application runs. You may wish to expand on this design to include additional features, such as allowing users to set their own tag colors, and directly saving the colors to storage, so that tags retain their colors even if the hash code algorithm changes.
Modify NewResultAvailableEvent such that ResultDisplay can show a different style on error (currently it shows the same regardless of errors).

Before

After
- Hints
  
  NewResultAvailableEvent is raised by CommandBox which also knows whether the result is a success or failure, and is caught by ResultDisplay which is where we want to change the style to.
  
  Refer to CommandBox for an example on how to display an error.
- Solution
  
  Modify NewResultAvailableEvent 's constructor so that users of the event can indicate whether an error has occurred.
  
  Modify ResultDisplay#handleNewResultAvailableEvent(NewResultAvailableEvent) to react to this event appropriately.
  
  You can write two different kinds of tests to ensure that the functionality works:
  
  The unit tests for ResultDisplay can be modified to include verification of the color.
  
  The system tests AddressBookSystemTest#assertCommandBoxShowsDefaultStyle() and AddressBookSystemTest#assertCommandBoxShowsErrorStyle() to include verification for ResultDisplay as well.
  
  See this PR for the full solution.
  
  Do read the commits one at a time if you feel overwhelmed.
Modify the StatusBarFooter to show the total number of people in the UniLA.

Before

After
- Hints
  
  StatusBarFooter.fxml will need a new StatusBar. Be sure to set the GridPane.columnIndex properly for each StatusBar to avoid misalignment!
  
  StatusBarFooter needs to initialize the status bar on application start, and to update it accordingly whenever the UniLA is updated.
- Solution
  
  Modify the constructor of StatusBarFooter to take in the number of persons when the application just started.
  
  Use StatusBarFooter#handleAddressBookChangedEvent(AddressBookChangedEvent) to update the number of persons whenever there are new changes to the addressbook.
  
  For tests, modify StatusBarFooterHandle by adding a state-saving functionality for the total number of people status, just like what we did for save location and sync status.
  
  For system tests, modify AddressBookSystemTest to also verify the new total number of persons status bar.
  
  See this PR for the full solution.

`Storage` component

Scenario: You are in charge of storage. For your next project milestone, your team plans to implement a new feature of saving the UniLA to the cloud. However, the current implementation of the application constantly saves the UniLA after the execution of each command, which is not ideal if the user is working on limited internet connection. Your team decided that the application should instead save the changes to a temporary local backup file first, and only upload to the cloud after the user closes the application. Your job is to implement a backup API for the UniLA storage.

Do take a look at Section 2.5, “Storage component” before attempting to modify the Storage component.

Add a new method backupAddressBook(ReadOnlyAddressBook), so that the UniLA can be saved in a fixed temporary location.
- Hint
  
  Add the API method in AddressBookStorage interface.
  
  Implement the logic in StorageManager and JsonAddressBookStorage class.
- Solution
  
  See this PR for the full solution.

A.2. Creating a new command: `remark`

By creating this command, you will get a chance to learn how to implement a feature end-to-end, touching all major components of the app.

Scenario: You are a software maintainer for addressbook, as the former developer team has moved on to new projects. The current users of your application have a list of new feature requests that they hope the software will eventually have. The most popular request is to allow adding additional comments/notes about a particular contact, by providing a flexible remark field for each contact, rather than relying on tags alone. After designing the specification for the remark command, you are convinced that this feature is worth implementing. Your job is to implement the remark command.

A.2.1. Description

Edits the remark for a person specified in the INDEX.
Format: remark INDEX r/[REMARK]

Examples:

remark 1 r/Likes to drink coffee.
Edits the remark for the first person to Likes to drink coffee.
remark 1 r/
Removes the remark for the first person.

A.2.2. Step-by-step Instructions

[Step 1] Logic: Teach the app to accept 'remark' which does nothing

Let’s start by teaching the application how to parse a remark command. We will add the logic of remark later.

Main:

Add a RemarkCommand that extends Command. Upon execution, it should just throw an Exception.
Modify AddressBookParser to accept a RemarkCommand.

Tests:

Add RemarkCommandTest that tests that execute() throws an Exception.
Add new test method to AddressBookParserTest, which tests that typing "remark" returns an instance of RemarkCommand.

[Step 2] Logic: Teach the app to accept 'remark' arguments

Let’s teach the application to parse arguments that our remark command will accept. E.g. 1 r/Likes to drink coffee.

Main:

Modify RemarkCommand to take in an Index and String and print those two parameters as the error message.
Add RemarkCommandParser that knows how to parse two arguments, one index and one with prefix 'r/'.
Modify AddressBookParser to use the newly implemented RemarkCommandParser.

Tests:

Modify RemarkCommandTest to test the RemarkCommand#equals() method.
Add RemarkCommandParserTest that tests different boundary values for RemarkCommandParser.
Modify AddressBookParserTest to test that the correct command is generated according to the user input.

[Step 3] Ui: Add a placeholder for remark in `PersonCard`

Let’s add a placeholder on all our PersonCard s to display a remark for each person later.

Main:

Add a Label with any random text inside PersonListCard.fxml.
Add FXML annotation in PersonCard to tie the variable to the actual label.

Tests:

Modify PersonCardHandle so that future tests can read the contents of the remark label.

[Step 4] Model: Add `Remark` class

We have to properly encapsulate the remark in our Person class. Instead of just using a String, let’s follow the conventional class structure that the codebase already uses by adding a Remark class.

Main:

Add Remark to model component (you can copy from Address, remove the regex and change the names accordingly).
Modify RemarkCommand to now take in a Remark instead of a String.

Tests:

Add test for Remark, to test the Remark#equals() method.

[Step 5] Model: Modify `Person` to support a `Remark` field

Now we have the Remark class, we need to actually use it inside Person.

Main:

Add getRemark() in Person.
You may assume that the user will not be able to use the add and edit commands to modify the remarks field (i.e. the person will be created without a remark).
Modify SampleDataUtil to add remarks for the sample data (delete your data/addressbook.json so that the application will load the sample data when you launch it.)

[Step 6] Storage: Add `Remark` field to `JsonAdaptedPerson` class

We now have Remark s for Person s, but they will be gone when we exit the application. Let’s modify JsonAdaptedPerson to include a Remark field so that it will be saved.

Main:

Add a new JSON field for Remark.

Tests:

Fix invalidAndValidPersonAddressBook.json, typicalPersonsAddressBook.json, validAddressBook.json etc., such that the JSON tests will not fail due to a missing remark field.

[Step 6b] Test: Add withRemark() for `PersonBuilder`

Since Person can now have a Remark, we should add a helper method to PersonBuilder, so that users are able to create remarks when building a Person.

Tests:

Add a new method withRemark() for PersonBuilder. This method will create a new Remark for the person that it is currently building.
Try and use the method on any sample Person in TypicalPersons.

[Step 7] Ui: Connect `Remark` field to `PersonCard`

Our remark label in PersonCard is still a placeholder. Let’s bring it to life by binding it with the actual remark field.

Main:

Modify PersonCard's constructor to bind the Remark field to the Person 's remark.

Tests:

Modify GuiTestAssert#assertCardDisplaysPerson(…) so that it will compare the now-functioning remark label.

[Step 8] Logic: Implement `RemarkCommand#execute()` logic

We now have everything set up… but we still can’t modify the remarks. Let’s finish it up by adding in actual logic for our remark command.

Main:

Replace the logic in RemarkCommand#execute() (that currently just throws an Exception), with the actual logic to modify the remarks of a person.

Tests:

Update RemarkCommandTest to test that the execute() logic works.

A.2.3. Full Solution

See this PR for the step-by-step solution.

Appendix B: Product Scope

Target user profile:

has a need to manage a significant number of contacts
prefer desktop apps over other types
can type fast
prefers typing over mouse input
is reasonably comfortable using CLI apps

Value proposition: manage contacts faster than a typical mouse/GUI driven app

Appendix C: User Stories

Priorities: High (must have) - * * *, Medium (nice to have) - * *, Low (unlikely to have) - *

Priority As a … I want to … So that I can…

Priority	As a …	I want to …	So that I can…
`* * *`	new user	see usage instructions	refer to instructions when I forget how to use the App
`* * *`	user	add a new person
`* * *`	user	delete a person	remove entries that I no longer need
`* * *`	user	find a person by name	locate details of persons without having to go through the entire list
`* *`	user	hide private contact details by default	minimize chance of someone else seeing them by accident
`*`	user with many persons in the UniLA	sort persons by name	locate a person easily
`* * *`	user	add a new event
`* * *`	user	delete an event	remove the events that I have attended
`* * *`	user	edit an event	modify the events details
`* * *`	user	list all events	see all the events that I have
`* * *`	user	connect a person to an event	add a person as participant to an event
`* * *`	user	disconnect a person from an event	remove this person from the event
`* * *`	user	meet people	find common free timeslot and create event with people

* * *

new user

see usage instructions

refer to instructions when I forget how to use the App

* * *

user

add a new person

* * *

user

delete a person

remove entries that I no longer need

* * *

user

find a person by name

locate details of persons without having to go through the entire list

* *

user

hide private contact details by default

minimize chance of someone else seeing them by accident

*

user with many persons in the UniLA

sort persons by name

locate a person easily

* * *

user

add a new event

* * *

user

delete an event

remove the events that I have attended

* * *

user

edit an event

modify the events details

* * *

user

list all events

see all the events that I have

* * *

user

connect a person to an event

add a person as participant to an event

* * *

user

disconnect a person from an event

remove this person from the event

* * *

user

meet people

find common free timeslot and create event with people

Appendix D: Use Cases

(For all use cases below, the System is the UniLA and the Actor is the user, unless specified otherwise)

Use case: Add person / event

MSS

User inputs text to console to add person/event.
UniLA acknowledges and adds person/event to the list.
UniLA is updated with a latest list of persons/events.

Use case ends.

Extensions

1a. The format of parameters entered are invalid.
- 1a1. UniLA shows an error message.
  
  Use case resumes at step 1.

Use case: Delete person/event

MSS

User requests to list persons/events
UniLA shows a list of persons/events
User requests to delete a specific person/event in the list
UniLA deletes the person/event

Use case ends.

Extensions

2a. The list is empty.

Use case ends.
3a. The given index is invalid.
- 3a1. UniLA shows an error message.
  
  Use case resumes at step 2.

Use case: Edit person/event

MSS

User requests to edit a specific person/event in the list.
UniLA updates itself.

Use case ends.

Extensions

1a. The list is empty.
- 1a1. UniLA shows an error message.
  
  Use case ends.
1b. The arguments for edit command are invalid.
- 1b1. UniLA shows an error message.
  
  Use case resumes at step 1.

Use case: List persons/events

MSS

User request to list all the persons/events.
UniLA displays list of persons.

Use case ends.

Extensions

1a. There is no event/person in UniLA.
- UniLA shows a successful message.
  
  Use case ends.

Appendix E: Non Functional Requirements

Should work on any mainstream OS as long as it has Java 9 or higher installed.
Should be able to hold up to 1000 persons without a noticeable sluggishness in performance for typical usage.
A user with above average typing speed for regular English text (i.e. not code, not system admin commands) should be able to accomplish most of the tasks faster using commands than using the mouse.

{More to be added}

Appendix F: Glossary

Mainstream OS: Windows, Linux, Unix, OS-X
Private contact detail: A contact detail that is not meant to be shared with others

Appendix G: Product Survey

Product Name

Author: …

Pros:

Cons:

Appendix H: Instructions for Manual Testing

Given below are instructions to test the app manually.

These instructions only provide a starting point for testers to work on; testers are expected to do more exploratory testing.

H.1. Launch and Shutdown

Initial launch
1. Download the jar file and copy into an empty folder
2. Double-click the jar file
  Expected: Shows the GUI with a set of sample contacts. The window size may not be optimum.
Saving window preferences
1. Resize the window to an optimum size. Move the window to a different location. Close the window.
2. Re-launch the app by double-clicking the jar file.
  Expected: The most recent window size and location is retained.

{ more test cases … }

H.2. Deleting a person

Deleting a person while all persons are listed
1. Prerequisites: List all persons using the list command. Multiple persons in the list.
2. Test case: delete 1
  Expected: First contact is deleted from the list. Details of the deleted contact shown in the status message. Timestamp in the status bar is updated.
3. Test case: delete 0
  Expected: No person is deleted. Error details shown in the status message. Status bar remains the same.
4. Other incorrect delete commands to try: delete, delete x (where x is larger than the list size) {give more}
  Expected: Similar to previous.

{ more test cases … }

H.3. Delete an event

Delete an event while all events are listed.
1. Prerequisites:List all events using the listE command. Multiple events in the list. Delete all reminders relate to this event using deleteR e/1.
2. Test case: deleteE 1
  Expected: 1st event deleted.

H.4. Saving data

Dealing with missing/corrupted data files
1. {explain how to simulate a missing/corrupted file and the expected behavior}

{ more test cases … }

H.5. Meeting planner

Meeting multiple people
1. Prerequisites: List all persons using the list command. At least 5 persons must be in the list.
2. Prerequisites: List all events using listE command. No events must be in the list.
3. Test case: meet 1 2
  Expected: A 2-hour event with the first two people in this list is created. The event should start in the next hour the user enters the command.
4. meet 2 3
  Expected: A 2-hour event with the second and third persons in this list is created. This event should start right after the previous event was created.
5. switch
  edit 1 n/Another Name
  listE
  select 1 Expected: The first event should update the changes in the first person’s name
6. meet 4 5 duration/0 3 0 0
  Expected: A 3-hour event with the fourth and fifth persons in this list is created. This event should start in the next hour the user enters the command.
7. Test case 2: meet 1
  Expected: An error is thrown saying that more than one person must be involved in this event.
8. Test case 3: meet 10000000000000 100000000001
  Expected: An error is thrown saying that the indices are invalid.
9. Test case 4: meet 1 1 2 2 2
  Expected: The command works as per normal. Duplicates should be ignored.

UniLA - Developer Guide

How the architecture components interact with each other

Logic component

Model component

Ui component

Storage component

Use case: Add person / event

Use case: Delete person/event

Use case: Edit person/event

Use case: List persons/events

`Logic` component

`Model` component

`Ui` component

`Storage` component