blob: 3306a9aa36966fe4226be18dceccdef23fd98108 [file]
'use strict';
exports.type = 'perItem';
exports.active = true;
exports.description = 'Sorts children of <defs> to improve compression';
/**
* Sorts children of defs in order to improve compression.
* Sorted first by frequency then by element name length then by element name (to ensure grouping).
*
* @param {Object} item current iteration item
* @return {Boolean} if false, item will be filtered out
*
* @author David Leston
*/
exports.fn = function (item) {
if (item.isElem('defs')) {
var frequency = item.children.reduce(function (frequency, child) {
if (child.name in frequency) {
frequency[child.name]++;
} else {
frequency[child.name] = 1;
}
return frequency;
}, {});
item.children.sort(function (a, b) {
var frequencyComparison = frequency[b.name] - frequency[a.name];
if (frequencyComparison !== 0) {
return frequencyComparison;
}
var lengthComparison = b.name.length - a.name.length;
if (lengthComparison !== 0) {
return lengthComparison;
}
return a.name != b.name ? (a.name > b.name ? -1 : 1) : 0;
});
return true;
}
};