Jonathan Tan Jit Ming - Project Portfolio

Ensured consistency in the language, formatting and structure of the project’s documentation. These changes can be seen in Pull Requests (PRs) #65, #66, #68, #89, #90, #95, #173, #180, #183, #185, and #189.

Reviewed PRs made by teammates by providing meaningful comments, where necessary. The PRs I reviewed include #72, #73, #76, #91, #94, #98, #109, #128, #170, #179, #186, #187 and #188.

User enters command stats command e.g. stats n/7 p/d m/t. The command is received by ExpenseTrackerParser, which calls creates StatsCommand and calls StatsCommandParser#parse() to create StatsCommand.

If no parameters are provided by the user, StatsCommand#StatsCommand() is called to create StatsCommand with the default parameters of periodAmount as 7, period as d and mode as t. Otherwise, StatsCommand#StatsCommand(periodAmount, period, mode) is called to create StatsCommand with the specified parameters.

StatsCommand checks if the parameters are valid. If any parameter is invalid, an exception will be raised and a message will be displayed to the user. Otherwise, the parameters are stored in instance variables and StatsCommand is returned to LogicManager.

LogicManager then calls StatsCommand#execute(), which updates expensePredicate, statsMode, statsPeriod and periodAmount in ModelManager, which are variables in ModelManager relevant for statistics. StatsCommand#execute() also posts ShowStatsRequestEvent and SwapLeftPanelEvent events to EventsCenter.

The ShowStatsRequestEvent event is handled by MainWindow#handleShowStatsEvent(), which calls 'StatisticsPanel#setData()' and passes the data as parameters by calling Logic#getExpenseStats(), Logic#getStatsPeriod(), Logic#getStatsMode() and Logic#getPeriodAmount().

Logic#getExpenseStats() gets the filtered expense list by calling Model#getExpenseStats(), which returns an unmodifiable ObservableList, only containing only expenses in the last 7 days, as per ModelManager#expensePredicate, and sorted by date.

Logic#getExpenseStats() then organises the data into a LinkedHashMap<String, Double>, where the key value pair represents the data series of the chart. If StatsMode is set to TIME, the key and value pair represents date and cost. If StatsMode is set to CATEGORY, the key value pair represents category and cost. Regardless of mode, the values are cumulative and is implemented using the algorithm in the following code snippet, using the example of category mode:

LinkedHashMap<String, Double> stats = new LinkedHashMap<>();
for (Expense e : expenseList) {
    String category;
    category = e.getCategory().categoryName;

    if (stats.containsKey(category)) {
        stats.put(
                category,
                stats.get(category) + e.getCost().getCostValue()
        );
    } else {
        stats.put(category, e.getCost().getCostValue());
    }
}

Logic#getStatsPeriod(), Logic#getStatsMode() and Logic#getPeriodAmount() gets their respective data by calling the method of the same name in Model.

Once the parameters are passed into StatisticsPanel#setData(), StackPane#getChildren()#clear() is called to clear any display elements in StackPane. JavaFX’s BarChart and PieChart are used to render the charts. There are three scenarios which could happen: