dimple-js/src/methods/_rollUp.js

Dimple is an object-oriented API allowing you to create flexible axis-based charts using [d3.js](http://d3js.org "d3.js").

    // Copyright: 2015 AlignAlytics
    // License: "https://github.com/PMSI-AlignAlytics/dimple/blob/master/MIT-LICENSE.txt"
    // Source: /src/methods/_rollUp.js
    dimple._rollUp = function (data, fields, includeFields) {

        var returnList = [];
        // Put single values into single value arrays
        if (fields !== null && fields !== undefined) {
            fields = [].concat(fields);
        } else {
            fields = [];
        }
        // Iterate every row in the data
        data.forEach(function (d) {
            // The index of the corresponding row in the return list
            var index = -1,
                newRow = {},
                match = true;
            // Find the corresponding value in the return list
            returnList.forEach(function (r, j) {
                if (index === -1) {
                    // Indicates a match
                    match = true;
                    // Iterate the passed fields and compare
                    fields.forEach(function (f) {
                        match = match && d[f] === r[f];
                    }, this);
                    // If this is a match get the index
                    if (match) {
                        index = j;
                    }
                }
            }, this);
            // Pick up the matched row, or add a new one
            if (index !== -1) {
                newRow = returnList[index];
            } else {
                // Iterate the passed fields and add to the new row
                fields.forEach(function (f) {
                    newRow[f] = d[f];
                }, this);
                returnList.push(newRow);
                index = returnList.length - 1;
            }
            // Iterate all the fields in the data
            includeFields.forEach(function (field) {
                if (fields.indexOf(field) === -1) {
                    if (newRow[field] === undefined) {
                        newRow[field] = [];
                    }
                    newRow[field] = newRow[field].concat(d[field]);
                }
            }, this);
            // Update the return list
            returnList[index] = newRow;
        }, this);
        // Return the flattened list
        return returnList;
    };