Rally SDK 2.0: How to display multiple data columns with a TimeSeriesCalculator - charts

Question

I would like to display 2 time series of data with columns in the same "Rally.ui.chart.Chart". The config below for "Rally.data.lookback.calculator.TimeSeriesCalculator" stacks the columns on the same X column. Is there an easy way to group the data to be shown side-by-side instead for the same date (like the "accepted" and "time remaining" in the iteration burn-down chart) ?
Perhaps something like this?
getMetrics: function () {
return [
{
"field": "TaskRemainingTotal",
"as": "Hours Remaining",
"f": "sum",
"display": "column"
},
{
"field": "PlanEstimate",
"as": "Story Points Accepted",
"f": "filteredSum",
"filterField": "ScheduleState",
"filterValues": ["Accepted", "Verified"],
"display": "column",
"group": "1" //????? is there a specifier to separate this data?
},
];
},

Answer 1

Here is the code for the calculator used for the burn chart:
https://github.com/RallyApps/app-catalog/blob/master/src/apps/charts/burndown/BurnDownCalculator.js
Writing calculators for generating charts from lookback api is probably the most difficult thing to do in the app platform, so kudos for tackling it!
I'm not an expert either, but hopefully that above code is enough to point you in the right direction. Please post back if you either solve it or run into a new issue.
I was able to get it to work by adding the following to the chartConfig:
plotOptions: {
column: {
stacking: null
}
}

Answer 2

I've found some more on this subject that I believe may be helpful:
The "stack" member of the series config in highcharts allows a series to be stacked by name. We can create a much more flexible system that allow us to specify how to stack the data by using this and overriding some methods in the Rally.data.lookback.calculator.TimeSeriesCalculator to allow the series data to be modified.
prepareChartData returns series data, so we can override the output of that to add series data:
prepareChartData: function(store) {
var snapshots = [];
store.each(function(record) {
snapshots.push(record.raw);
});
var a = this.runCalculation(snapshots);
for (var k in a.series) {
if (a.series[k].name.startsWith("Story")) a.series[k].stack = "Story";
}
return a;
}
we can override the _buildSeriesConfig function to push any properties listed in the seriesConfig array in the metric config to the series config. This allows us to specify the series formatting in a nicer way and also gives us much more power in modifying other attributes of the chart config :
_buildSeriesConfig: function(calculatorConfig) {
var aggregationConfig = [],
metrics = calculatorConfig.metrics,
derivedFieldsAfterSummary = calculatorConfig.deriveFieldsAfterSummary;
for (var i = 0, ilength = metrics.length; i < ilength; i += 1) {
var metric = metrics[i];
var seriesConfig = {
name: metric.as || metric.field,
type: metric.display,
dashStyle: metric.dashStyle || "Solid"
};
for (var k in metric.seriesConfig) {
seriesConfig[k] = metric.seriesConfig[k];
}
aggregationConfig.push(seriesConfig);
}
for (var j = 0, jlength = derivedFieldsAfterSummary.length; j < jlength; j += 1) {
var derivedField = derivedFieldsAfterSummary[j];
var seriesConfig = {
name: derivedField.as,
type: derivedField.display,
dashStyle: derivedField.dashStyle || "Solid"
};
for (var k in derivedField.seriesConfig) {
seriesConfig[k] = derivedField.seriesConfig[k];
}
aggregationConfig.push(seriesConfig);
}
return aggregationConfig;
},
this method allows us to supply a seriesConfig property in getMetrics like so:
getMetrics: function() {
return [{
"field": "TaskRemainingTotal", // the field in the data to operate on
"as": "Hours Remaining", // the label to appear on the chart
"f": "sum", // summing function to use.
"display": "column", // how to display the point on the chart.
seriesConfig: {
"stack": "Hours",
"color": "#005eb8"
}
}, {
"field": "PlanEstimate", // the field in the data to operate on
"as": "Story Points Accepted", // the label to appear on the chart
"f": "filteredSum",
"filterField": "ScheduleState", // Only use points in seduled sate accepted or Verified
"filterValues": ["Accepted", "Verified"],
"display": "column",
seriesConfig: {
"stack": "Points",
"color": "#8dc63f"
}
}, {
"field": "PlanEstimate", // the field in the data to operate on
"as": "Story Points Remaining", // the label to appear on the chart
"f": "filteredSum",
"filterField": "ScheduleState", // Only use points in seduled sate accepted or Verified
"filterValues": ["Idea", "Defined", "In Progress", "Completed"],
"display": "column",
seriesConfig: {
"stack": "Points",
"color": "#c0c0c0"
}
},
];
},
With option #2, we can control and add any series config data in the same context that we are configuring the metrics, without worrying about configuration orders. Option #2 is a little dangerous though as the underscore implies that the method is private and therefore has no contractual guarantee to remain compatible in future revisions. (Maybe the rally guys will see this and extend the functionality for us)