webui-aria2/js/libs/dojo/store/DataStore.js.uncompressed.js
2012-05-01 19:52:07 +08:00

172 lines
5.1 KiB
JavaScript

//>>built
define("dojo/store/DataStore", ["../_base/lang", "../_base/declare", "../_base/Deferred", "../_base/array", "./util/QueryResults"
], function(lang,declare,Deferred,array,QueryResults) {
// module:
// dojo/store/DataStore
// summary:
// TODOC
return declare("dojo.store.DataStore", null, {
target: "",
constructor: function(options){
// summary:
// This is an adapter for using Dojo Data stores with an object store consumer.
// You can provide a Dojo data store and use this adapter to interact with it through
// the Dojo object store API
// options: Object?
// This provides any configuration information that will be mixed into the store,
// including a reference to the Dojo data store under the property "store".
lang.mixin(this, options);
if(!"idProperty" in options){
var idAttribute;
try{
idAttribute = this.store.getIdentityAttributes();
}catch(e){
// some store are not requiring an item instance to give us the ID attributes
// but some other do and throw errors in that case.
}
// if no idAttribute we have implicit id
this.idProperty = (!idAttribute || !idAttributes[0]) || this.idProperty;
}
var features = this.store.getFeatures();
// check the feature set and null out any methods that shouldn't be available
if(!features["dojo.data.api.Read"]){
this.get = null;
}
if(!features["dojo.data.api.Identity"]){
this.getIdentity = null;
}
if(!features["dojo.data.api.Write"]){
this.put = this.add = null;
}
},
// idProperty: String
// The object property to use to store the identity of the store items.
idProperty: "id",
// store:
// The object store to convert to a data store
store: null,
_objectConverter: function(callback){
var store = this.store;
var idProperty = this.idProperty;
return function(item){
var object = {};
var attributes = store.getAttributes(item);
for(var i = 0; i < attributes.length; i++){
object[attributes[i]] = store.getValue(item, attributes[i]);
}
if(!(idProperty in object)){
object[idProperty] = store.getIdentity(item);
}
return callback(object);
};
},
get: function(id, options){
// summary:
// Retrieves an object by it's identity. This will trigger a fetchItemByIdentity
// id: Object?
// The identity to use to lookup the object
var returnedObject, returnedError;
var deferred = new Deferred();
this.store.fetchItemByIdentity({
identity: id,
onItem: this._objectConverter(function(object){
deferred.resolve(returnedObject = object);
}),
onError: function(error){
deferred.reject(returnedError = error);
}
});
if(returnedObject){
// if it was returned synchronously
return returnedObject;
}
if(returnedError){
throw returnedError;
}
return deferred.promise;
},
put: function(object, options){
// summary:
// Stores an object by its identity.
// object: Object
// The object to store.
// options: Object?
// Additional metadata for storing the data. Includes a reference to an id
// that the object may be stored with (i.e. { id: "foo" }).
var id = options && typeof options.id != "undefined" || this.getIdentity(object);
var store = this.store;
var idProperty = this.idProperty;
if(typeof id == "undefined"){
store.newItem(object);
}else{
store.fetchItemByIdentity({
identity: id,
onItem: function(item){
if(item){
for(var i in object){
if(i != idProperty && // don't copy id properties since they are immutable and should be omitted for implicit ids
store.getValue(item, i) != object[i]){
store.setValue(item, i, object[i]);
}
}
}else{
store.newItem(object);
}
}
});
}
},
remove: function(id){
// summary:
// Deletes an object by its identity.
// id: Object
// The identity to use to delete the object
var store = this.store;
this.store.fetchItemByIdentity({
identity: id,
onItem: function(item){
store.deleteItem(item);
}
});
},
query: function(query, options){
// summary:
// Queries the store for objects.
// query: Object
// The query to use for retrieving objects from the store
// options: Object?
// Optional options object as used by the underlying dojo.data Store.
// returns: dojo.store.util.QueryResults
// A query results object that can be used to iterate over results.
var fetchHandle;
var deferred = new Deferred(function(){ fetchHandle.abort && fetchHandle.abort(); });
deferred.total = new Deferred();
var converter = this._objectConverter(function(object){return object;});
fetchHandle = this.store.fetch(lang.mixin({
query: query,
onBegin: function(count){
deferred.total.resolve(count);
},
onComplete: function(results){
deferred.resolve(array.map(results, converter));
},
onError: function(error){
deferred.reject(error);
}
}, options));
return QueryResults(deferred);
},
getIdentity: function(object){
// summary:
// Fetch the identity for the given object.
// object: Object
// The data object to get the identity from.
// returns: Number
// The id of the given object.
return object[this.idProperty];
}
});
});