source: [view]
dojo.provide("dojox.charting.DataSeries");
dojo.require("dojox.lang.functional");
dojo.declare("dojox.charting.DataSeries", null, {
constructor: function(store, kwArgs, value){
// summary:
// Series adapter for dojo.data stores.
// store: Object:
// A dojo.data store object.
// kwArgs: Object:
// A store-specific keyword parameters used for fetching items.
// See dojo.data.api.Read.fetch().
// value: Function|Object|String|Null:
// Function, which takes a store, and 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(dojo.isFunction(value)){
this.value = value;
}else if(dojo.isObject(value)){
this.value = dojo.hitch(this, "_dictValue",
dojox.lang.functional.keys(value), value);
}else{
this.value = dojo.hitch(this, "_fieldValue", value);
}
}else{
this.value = dojo.hitch(this, "_defaultValue");
}
this.data = [];
this._events = [];
if(this.store.getFeatures()["dojo.data.api.Notification"]){
this._events.push(
dojo.connect(this.store, "onNew", this, "_onStoreNew"),
dojo.connect(this.store, "onDelete", this, "_onStoreDelete"),
dojo.connect(this.store, "onSet", this, "_onStoreSet")
);
}
this.fetch();
},
destroy: function(){
// summary:
// Clean up before GC.
dojo.forEach(this._events, dojo.disconnect);
},
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;
},
// value transformers
_dictValue: function(keys, dict, store, item){
var o = {};
dojo.forEach(keys, function(key){
o[key] = store.getValue(item, dict[key]);
});
return o;
},
_fieldValue: function(field, store, item){
return store.getValue(item, field);
},
_defaultValue: function(store, item){
return store.getValue(item, "value");
},
// store fetch loop
fetch: function(){
// summary:
// Fetches data from the store and updates a chart.
if(!this._inFlight){
this._inFlight = true;
var kwArgs = dojo.delegate(this.kwArgs);
kwArgs.onComplete = dojo.hitch(this, "_onFetchComplete");
kwArgs.onError = dojo.hitch(this, "onFetchError");
this.store.fetch(kwArgs);
}
},
_onFetchComplete: function(items, request){
this.items = items;
this._buildItemMap();
this.data = dojo.map(this.items, function(item){
return this.value(this.store, item);
}, this);
this._pushDataChanges();
this._inFlight = false;
},
onFetchError: function(errorData, request){
// summary:
// As stub to process fetch errors. Provide so user can attach to
// it with dojo.connect(). See dojo.data.api.Read fetch() for
// details: onError property.
this._inFlight = false;
},
_buildItemMap: function(){
if(this.store.getFeatures()["dojo.data.api.Identity"]){
var itemMap = {};
dojo.forEach(this.items, function(item, index){
itemMap[this.store.getIdentity(item)] = index;
}, this);
this.itemMap = itemMap;
}
},
_pushDataChanges: function(){
if(this.series){
this.series.chart.updateSeries(this.series.name, this);
this.series.chart.delayedRender();
}
},
// store notification handlers
_onStoreNew: function(){
// the only thing we can do is to re-fetch items
this.fetch();
},
_onStoreDelete: function(item){
// we cannot do anything with deleted item, the only way is to compare
// items for equality
if(this.items){
var flag = dojo.some(this.items, function(it, index){
if(it === item){
this.items.splice(index, 1);
this._buildItemMap();
this.data.splice(index, 1);
return true;
}
return false;
}, this);
if(flag){
this._pushDataChanges();
}
}