reductio/src/nest.js

Reductio: Crossfilter groupings

import crossfilter from 'crossfilter2';

var nest = {
	add: function (keyAccessors, prior, path) {
		var i; // Current key accessor
		var arrRef;
		var newRef;
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);

			arrRef = path(p).nest;
			keyAccessors.forEach(function(a) {
				newRef = arrRef.filter(function(d) { return d.key === a(v); })[0];
				if(newRef) {
					// There is another level.
					arrRef = newRef.values;
				} else {
					// Next level doesn't yet exist so we create it.
					newRef = [];
					arrRef.push({ key: a(v), values: newRef });
					arrRef = newRef;
				}
			});

			arrRef.push(v);
			
			return p;
		};
	},
	remove: function (keyAccessors, prior, path) {
		var arrRef;
		return function (p, v, nf) {
			if(prior) prior(p, v, nf);

			arrRef = path(p).nest;
			keyAccessors.forEach(function(a) {
				arrRef = arrRef.filter(function(d) { return d.key === a(v); })[0].values;
			});

			// Array contains an actual reference to the row, so just splice it out.
			arrRef.splice(arrRef.indexOf(v), 1);

			// If the leaf now has length 0 and it's not the base array remove it.
			// TODO

			return p;
		};
	},
	initial: function (prior, path) {
		return function (p) {
			p = prior(p);
			path(p).nest = [];
			return p;
		};
	}
};

export default nest;