source: Dev/branches/rest-dojo-ui/client/dojo/data/ObjectStore.js @ 256

define(["../_base/lang", "../Evented", "../_base/declare", "../_base/Deferred", "../_base/array", 
        "../_base/connect", "../regexp"
], function(lang, Evented, declare, Deferred, array, connect, regexp) {
        // module:
        //              dojo/data/ObjectStore
        // summary:
        //              TODOC


return declare("dojo.data.ObjectStore", [Evented],{
                objectStore: null,
                constructor: function(options){
                        // summary:
                        //              A Dojo Data implementation that wraps Dojo object stores for backwards
                        //              compatibility.
                        //      options:
                        //              The configuration information to pass into the data store.
                        //      options.objectStore:
                        //              The object store to use as the source provider for this data store
                        lang.mixin(this, options);
                },
                labelProperty: "label",

                getValue: function(/*Object*/ item, /*String*/property, /*value?*/defaultValue){
                        // summary:
                        //      Gets the value of an item's 'property'
                        //
                        //      item:
                        //              The item to get the value from
                        //      property:
                        //              property to look up value for
                        //      defaultValue:
                        //              the default value

                        return typeof item.get === "function" ? item.get(property) :
                                property in item ?
                                        item[property] : defaultValue;
                },
                getValues: function(item, property){
                        // summary:
                        //              Gets the value of an item's 'property' and returns
                        //              it. If this value is an array it is just returned,
                        //              if not, the value is added to an array and that is returned.
                        //
                        //      item: /* object */
                        //      property: /* string */
                        //              property to look up value for

                        var val = this.getValue(item,property);
                        return val instanceof Array ? val : val === undefined ? [] : [val];
                },

                getAttributes: function(item){
                        // summary:
                        //      Gets the available attributes of an item's 'property' and returns
                        //      it as an array.
                        //
                        //      item: /* object */

                        var res = [];
                        for(var i in item){
                                if(item.hasOwnProperty(i) && !(i.charAt(0) == '_' && i.charAt(1) == '_')){
                                        res.push(i);
                                }
                        }
                        return res;
                },

                hasAttribute: function(item,attribute){
                        // summary:
                        //              Checks to see if item has attribute
                        //
                        //      item: /* object */
                        //      attribute: /* string */
                        return attribute in item;
                },

                containsValue: function(item, attribute, value){
                        // summary:
                        //              Checks to see if 'item' has 'value' at 'attribute'
                        //
                        //      item: /* object */
                        //      attribute: /* string */
                        //      value: /* anything */
                        return array.indexOf(this.getValues(item,attribute),value) > -1;
                },


                isItem: function(item){
                        // summary:
                        //              Checks to see if the argument is an item
                        //
                        //      item: /* object */
                        //      attribute: /* string */

                        // we have no way of determining if it belongs, we just have object returned from
                        //      service queries
                        return (typeof item == 'object') && item && !(item instanceof Date);
                },

                isItemLoaded: function(item){
                        // summary:
                        //              Checks to see if the item is loaded.
                        //
                        //              item: /* object */

                        return item && typeof item.load !== "function";
                },

                loadItem: function(args){
                        // summary:
                        //              Loads an item and calls the callback handler. Note, that this will call the callback
                        //              handler even if the item is loaded. Consequently, you can use loadItem to ensure
                        //              that an item is loaded is situations when the item may or may not be loaded yet.
                        //              If you access a value directly through property access, you can use this to load
                        //              a lazy value as well (doesn't need to be an item).
                        //
                        //      example:
                        //              store.loadItem({
                        //                      item: item, // this item may or may not be loaded
                        //                      onItem: function(item){
                        //                              // do something with the item
                        //                      }
                        //              });

                        var item;
                        if(typeof args.item.load === "function"){
                                Deferred.when(args.item.load(), function(result){
                                        item = result; // in synchronous mode this can allow loadItem to return the value
                                        var func = result instanceof Error ? args.onError : args.onItem;
                                        if(func){
                                                func.call(args.scope, result);
                                        }
                                });
                        }else if(args.onItem){
                                // even if it is already loaded, we will use call the callback, this makes it easier to
                                // use when it is not known if the item is loaded (you can always safely call loadItem).
                                args.onItem.call(args.scope, args.item);
                        }
                        return item;
                },
                close: function(request){
                        return request && request.abort && request.abort();
                },
                fetch: function(args){
                        // summary:
                        //              See dojo.data.api.Read.fetch
                        //

                        args = lang.delegate(args, args && args.queryOptions);
                        var self = this;
                        var scope = args.scope || self;
                        var query = args.query;
                        if(typeof query == "object"){ // can be null, but that is ignore by for-in
                                query = lang.delegate(query); // don't modify the original
                                for(var i in query){
                                        // find any strings and convert them to regular expressions for wildcard support
                                        var required = query[i];
                                        if(typeof required == "string"){
                                                query[i] = RegExp("^" + regexp.escapeString(required, "*?").replace(/\*/g, '.*').replace(/\?/g, '.') + "$", args.ignoreCase ? "mi" : "m");
                                                query[i].toString = (function(original){
                                                        return function(){
                                                                return original;
                                                        }
                                                })(required);
                                        }
                                }
                        }

                        var results = this.objectStore.query(query, args);
                        Deferred.when(results.total, function(totalCount){
                                Deferred.when(results, function(results){
                                        if(args.onBegin){
                                                args.onBegin.call(scope, totalCount || results.length, args);
                                        }
                                        if(args.onItem){
                                                for(var i=0; i<results.length;i++){
                                                        args.onItem.call(scope, results[i], args);
                                                }
                                        }
                                        if(args.onComplete){
                                                args.onComplete.call(scope, args.onItem ? null : results, args);
                                        }
                                        return results;
                                }, errorHandler);
                        }, errorHandler);
                        function errorHandler(error){
                                if(args.onError){
                                        args.onError.call(scope, error, args);
                                }
                        }
                        args.abort = function(){
                                // abort the request
                                if(results.cancel){
                                        results.cancel();
                                }
                        };
                        if(results.observe){
                                if(this.observing){
                                        // if we were previously observing, cancel the last time to avoid multiple notifications. Just the best we can do for the impedance mismatch between APIs
                                        this.observing.cancel();
                                }
                                this.observing = results.observe(function(object, removedFrom, insertedInto){
                                        if(array.indexOf(self._dirtyObjects, object) == -1){
                                                if(removedFrom == -1){
                                                        self.onNew(object);
                                                }
                                                else if(insertedInto == -1){
                                                        self.onDelete(object);
                                                }
                                                else{
                                                        for(var i in object){
                                                                if(i != self.objectStore.idProperty){
                                                                        self.onSet(object, i, null, object[i]);
                                                                }
                                                        }
                                                }
                                        }
                                }, true);
                        }
                        this.onFetch(results);
                        args.store = this;
                        return args;
                },
                getFeatures: function(){
                        // summary:
                        //              return the store feature set

                        return {
                                "dojo.data.api.Read": !!this.objectStore.get,
                                "dojo.data.api.Identity": true,
                                "dojo.data.api.Write": !!this.objectStore.put,
                                "dojo.data.api.Notification": true
                        };
                },

                getLabel: function(/* item */ item){
                        //      summary:
                        //              See dojo.data.api.Read.getLabel()
                        if(this.isItem(item)){
                                return this.getValue(item,this.labelProperty); //String
                        }
                        return undefined; //undefined
                },

                getLabelAttributes: function(/* item */ item){
                        //      summary:
                        //              See dojo.data.api.Read.getLabelAttributes()
                        return [this.labelProperty]; //array
                },

                //Identity API Support


                getIdentity: function(item){
                        return this.objectStore.getIdentity ? this.objectStore.getIdentity(item) : item[this.objectStore.idProperty || "id"];
                },

                getIdentityAttributes: function(item){
                        // summary:
                        //              returns the attributes which are used to make up the
                        //              identity of an item.    Basically returns this.objectStore.idProperty

                        return [this.objectStore.idProperty];
                },

                fetchItemByIdentity: function(args){
                        // summary:
                        //              fetch an item by its identity, by looking in our index of what we have loaded
                        var item;
                        Deferred.when(this.objectStore.get(args.identity),
                                function(result){
                                        item = result;
                                        args.onItem.call(args.scope, result);
                                },
                                function(error){
                                        args.onError.call(args.scope, error);
                                }
                        );
                        return item;
                },

                newItem: function(data, parentInfo){
                        // summary:
                        //              adds a new item to the store at the specified point.
                        //              Takes two parameters, data, and options.
                        //
                        //      data: Object
                        //              The data to be added in as an item.
                        
                        // TODOC: parentInfo
                        if(parentInfo){
                                // get the previous value or any empty array
                                var values = this.getValue(parentInfo.parent,parentInfo.attribute,[]);
                                // set the new value
                                values = values.concat([data]);
                                data.__parent = values;
                                this.setValue(parentInfo.parent, parentInfo.attribute, values);
                        }
                        this._dirtyObjects.push({object:data, save: true});
                        this.onNew(data);
                        return data;
                },
                deleteItem: function(item){
                        // summary:
                        //              deletes item and any references to that item from the store.
                        //
                        //      item:
                        //              item to delete
                        //

                        //      If the desire is to delete only one reference, unsetAttribute or
                        //      setValue is the way to go.
                        this.changing(item, true);

                        this.onDelete(item);
                },
                setValue: function(item, attribute, value){
                        // summary:
                        //              sets 'attribute' on 'item' to 'value'

                        var old = item[attribute];
                        this.changing(item);
                        item[attribute]=value;
                        this.onSet(item,attribute,old,value);
                },
                setValues: function(item, attribute, values){
                        // summary:
                        //      sets 'attribute' on 'item' to 'value' value
                        //      must be an array.

                        if(!lang.isArray(values)){
                                throw new Error("setValues expects to be passed an Array object as its value");
                        }
                        this.setValue(item,attribute,values);
                },

                unsetAttribute: function(item, attribute){
                        // summary:
                        //              unsets 'attribute' on 'item'

                        this.changing(item);
                        var old = item[attribute];
                        delete item[attribute];
                        this.onSet(item,attribute,old,undefined);
                },

                _dirtyObjects: [],

                changing: function(object,_deleting){
                        // summary:
                        //              adds an object to the list of dirty objects.  This object
                        //              contains a reference to the object itself as well as a
                        //              cloned and trimmed version of old object for use with
                        //              revert.
                        object.__isDirty = true;
                        //if an object is already in the list of dirty objects, don't add it again
                        //or it will overwrite the premodification data set.
                        for(var i=0; i<this._dirtyObjects.length; i++){
                                var dirty = this._dirtyObjects[i];
                                if(object==dirty.object){
                                        if(_deleting){
                                                // we are deleting, no object is an indicator of deletiong
                                                dirty.object = false;
                                                if(!this._saveNotNeeded){
                                                        dirty.save = true;
                                                }
                                        }
                                        return;
                                }
                        }
                        var old = object instanceof Array ? [] : {};
                        for(i in object){
                                if(object.hasOwnProperty(i)){
                                        old[i] = object[i];
                                }
                        }
                        this._dirtyObjects.push({object: !_deleting && object, old: old, save: !this._saveNotNeeded});
                },

                save: function(kwArgs){
                        // summary:
                        //              Saves the dirty data using object store provider. See dojo.data.api.Write for API.
                        //
                        //      kwArgs.global:
                        //              This will cause the save to commit the dirty data for all
                        //              ObjectStores as a single transaction.
                        //
                        //      kwArgs.revertOnError
                        //              This will cause the changes to be reverted if there is an
                        //              error on the save. By default a revert is executed unless
                        //              a value of false is provide for this parameter.

                        // TODOC: kwArgs pseudo
                        kwArgs = kwArgs || {};
                        var result, actions = [];
                        var savingObjects = [];
                        var self = this;
                        var dirtyObjects = this._dirtyObjects;
                        var left = dirtyObjects.length;// this is how many changes are remaining to be received from the server
                        try{
                                connect.connect(kwArgs,"onError",function(){
                                        if(kwArgs.revertOnError !== false){
                                                var postCommitDirtyObjects = dirtyObjects;
                                                dirtyObjects = savingObjects;
                                                self.revert(); // revert if there was an error
                                                self._dirtyObjects = postCommitDirtyObjects;
                                        }
                                        else{
                                                self._dirtyObjects = dirtyObjects.concat(savingObjects);
                                        }
                                });
                                if(this.objectStore.transaction){
                                        var transaction = this.objectStore.transaction();
                                }
                                for(var i = 0; i < dirtyObjects.length; i++){
                                        var dirty = dirtyObjects[i];
                                        var object = dirty.object;
                                        var old = dirty.old;
                                        delete object.__isDirty;
                                        if(object){
                                                result = this.objectStore.put(object, {overwrite: !!old});
                                        }
                                        else if(typeof old != "undefined"){
                                                result = this.objectStore.remove(this.getIdentity(old));
                                        }
                                        savingObjects.push(dirty);
                                        dirtyObjects.splice(i--,1);
                                        Deferred.when(result, function(value){
                                                if(!(--left)){
                                                        if(kwArgs.onComplete){
                                                                kwArgs.onComplete.call(kwArgs.scope, actions);
                                                        }
                                                }
                                        },function(value){

                                                // on an error we want to revert, first we want to separate any changes that were made since the commit
                                                left = -1; // first make sure that success isn't called
                                                kwArgs.onError.call(kwArgs.scope, value);
                                        });

                                }
                                if(transaction){
                                        transaction.commit();
                                }
                        }catch(e){
                                kwArgs.onError.call(kwArgs.scope, value);
                        }
                },

                revert: function(kwArgs){
                        // summary:
                        //              returns any modified data to its original state prior to a save();
                        //
                        var dirtyObjects = this._dirtyObjects;
                        for(var i = dirtyObjects.length; i > 0;){
                                i--;
                                var dirty = dirtyObjects[i];
                                var object = dirty.object;
                                var old = dirty.old;
                                if(object && old){
                                        // changed
                                        for(var j in old){
                                                if(old.hasOwnProperty(j) && object[j] !== old[j]){
                                                        this.onSet(object, j, object[j], old[j]);
                                                        object[j] = old[j];
                                                }
                                        }
                                        for(j in object){
                                                if(!old.hasOwnProperty(j)){
                                                        this.onSet(object, j, object[j]);
                                                        delete object[j];
                                                }
                                        }
                                }else if(!old){
                                        // was an addition, remove it
                                        this.onDelete(object);
                                }else{
                                        // was a deletion, we will add it back
                                        this.onNew(old);
                                }
                                delete (object || old).__isDirty;
                                dirtyObjects.splice(i, 1);
                        }

                },
                isDirty: function(item){
                        // summary:
                        //              returns true if the item is marked as dirty or true if there are any dirty items
                        if(!item){
                                return !!this._dirtyObjects.length;
                        }
                        return item.__isDirty;
                },
                //Notifcation Support

                onSet: function(){},
                onNew: function(){},
                onDelete:       function(){},
                // an extra to get result sets
                onFetch: function(results){}

        }
);
});