dojox/charting/StoreSeries.js

Dojo eXtensions, a rollup of many useful sub-projects and varying states of maturity – from very stable and robust, to alpha and experimental. See individual projects contain README files for details.

define(["dojo/_base/array", "dojo/_base/declare", "dojo/_base/Deferred"],
  function(arr, declare, Deferred){

	return declare("dojox.charting.StoreSeries", null, {
		constructor: function(store, kwArgs, value){
			// summary:
			//		Series adapter for dojo object stores (dojo/store).
			// store: Object
			//		A dojo object store.
			// kwArgs: Object
			//		A store-specific keyword parameters used for querying objects.
			//		See dojo/store docs
			// value: Function|Object|String
			//		Function, which takes an object handle, and
			//		produces an output possibly inspecting the store's item. Or
			//		a dictionary object, which tells what names to extract from
			//		an object and how to map them to an output. Or a string, which
			//		is a numeric field name to use for plotting. If undefined, null
			//		or empty string (the default), "value" field is extracted.
			this.store = store;
			this.kwArgs = kwArgs;

			if(value){
				if(typeof value == "function"){
					this.value = value;
				}else if(typeof value == "object"){
					this.value = function(object){
						var o = {};
						for(var key in value){
							o[key] = object[value[key]];
						}
						return o;
					};
				}else{
					this.value = function(object){
						return object[value];
					};
				}
			}else{
				this.value = function(object){
					return object.value;
				};
			}

			this.data = [];

			this._initialRendering = true;
			this.fetch();
		},

		destroy: function(){
			// summary:
			//		Clean up before GC.
			if(this.observeHandle){
				this.observeHandle.remove();
			}
		},

		setSeriesObject: function(series){
			// summary:
			//		Sets a dojox/charting/Series object we will be working with.
			// series: dojox/charting/Series
			//		Our interface to the chart.
			this.series = series;
		},

		// store fetch loop

		fetch: function(query, options){
			// summary:
			//		Fetches data from the store and updates a chart.
            // query: String | Object | Function
			//		Optional update to the query to use for retrieving objects from the store.
            // options: dojo/store/api/Store.QueryOptions
            //      Optional arguments to apply to the resultset.
			var self = this;
			if(this.observeHandle){
				this.observeHandle.remove();
			}
			var results = this.store.query(query || this.kwArgs.query, options || this.kwArgs);
			Deferred.when(results, function(objects){
				self.objects = objects;
				update();
			});
			if(results.observe){
				this.observeHandle = results.observe(update, true);
			}
			function update(){
				self.data = arr.map(self.objects, function(object){
					return self.value(object, self.store);
				});
				self._pushDataChanges();
			}
		},

		_pushDataChanges: function(){
			if(this.series){
				this.series.chart.updateSeries(this.series.name, this, this._initialRendering);
				this._initialRendering = false;
				this.series.chart.delayedRender();
			}
		}

	});
});