]> git.pond.sub.org Git - eow/blobdiff - static/dojo-release-1.1.1/dojox/data/QueryReadStore.js
add Dojo 1.1.1
[eow] / static / dojo-release-1.1.1 / dojox / data / QueryReadStore.js
diff --git a/static/dojo-release-1.1.1/dojox/data/QueryReadStore.js b/static/dojo-release-1.1.1/dojox/data/QueryReadStore.js
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+if(!dojo._hasResource["dojox.data.QueryReadStore"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
+dojo._hasResource["dojox.data.QueryReadStore"] = true;
+dojo.provide("dojox.data.QueryReadStore");
+
+dojo.require("dojo.string");
+
+dojo.declare("dojox.data.QueryReadStore",
+       null,
+       {
+               //      summary:
+               //              This class provides a store that is mainly intended to be used
+               //              for loading data dynamically from the server, used i.e. for
+               //              retreiving chunks of data from huge data stores on the server (by server-side filtering!).
+               //              Upon calling the fetch() method of this store the data are requested from
+               //              the server if they are not yet loaded for paging (or cached).
+               //
+               //              For example used for a combobox which works on lots of data. It
+               //              can be used to retreive the data partially upon entering the
+               //              letters "ac" it returns only items like "action", "acting", etc.
+               //
+               // note:
+               //              The field name "id" in a query is reserved for looking up data
+               //              by id. This is necessary as before the first fetch, the store
+               //              has no way of knowing which field the server will declare as
+               //              identifier.
+               //
+               //      examples:
+               // |    // The parameter "query" contains the data that are sent to the server.
+               // |    var store = new dojox.data.QueryReadStore({url:'/search.php'});
+               // |    store.fetch({query:{name:'a'}, queryOptions:{ignoreCase:false}});
+               //
+               // |    // Since "serverQuery" is given, it overrules and those data are
+               // |    // sent to the server.
+               // |    var store = new dojox.data.QueryReadStore({url:'/search.php'});
+               // |    store.fetch({serverQuery:{name:'a'}, queryOptions:{ignoreCase:false}});
+               //
+               // |    <div dojoType="dojox.data.QueryReadStore"
+               // |            jsId="store2"
+               // |            url="../tests/stores/QueryReadStore.php"
+               // |            requestMethod="post"></div>
+               // |    <div dojoType="dojox.grid.data.DojoData"
+               // |            jsId="model2"
+               // |            store="store2"
+               // |            sortFields="[{attribute: 'name', descending: true}]"
+               // |            rowsPerPage="30"></div>
+               // |    <div dojoType="dojox.Grid" id="grid2"
+               // |            model="model2"
+               // |            structure="gridLayout"
+               // |            style="height:300px; width:800px;"></div>
+       
+               //
+               //      todo:
+               //              - there is a bug in the paging, when i set start:2, count:5 after an initial fetch() and doClientPaging:true
+               //                it returns 6 elemetns, though count=5, try it in QueryReadStore.html
+               //              - add optional caching
+               //              - when the first query searched for "a" and the next for a subset of
+               //                the first, i.e. "ab" then we actually dont need a server request, if
+               //                we have client paging, we just need to filter the items we already have
+               //                that might also be tooo much logic
+               
+               url:"",
+               requestMethod:"get",
+               //useCache:false,
+               
+               // We use the name in the errors, once the name is fixed hardcode it, may be.
+               _className:"dojox.data.QueryReadStore",
+               
+               // This will contain the items we have loaded from the server.
+               // The contents of this array is optimized to satisfy all read-api requirements
+               // and for using lesser storage, so the keys and their content need some explaination:
+               //              this._items[0].i - the item itself 
+               //              this._items[0].r - a reference to the store, so we can identify the item
+               //                      securly. We set this reference right after receiving the item from the
+               //                      server.
+               _items:[],
+               
+               // Store the last query that triggered xhr request to the server.
+               // So we can compare if the request changed and if we shall reload 
+               // (this also depends on other factors, such as is caching used, etc).
+               _lastServerQuery:null,
+               
+               
+               // Store a hash of the last server request. Actually I introduced this
+               // for testing, so I can check if no unnecessary requests were issued for
+               // client-side-paging.
+               lastRequestHash:null,
+               
+               // summary:
+               //              By default every request for paging is sent to the server.
+               doClientPaging:false,
+       
+               // summary:
+               //              By default all the sorting is done serverside before the data is returned
+               //              which is the proper place to be doing it for really large datasets.
+               doClientSorting:false,
+       
+               // Items by identify for Identify API
+               _itemsByIdentity:null,
+               
+               // Identifier used
+               _identifier:null,
+       
+               _features: {'dojo.data.api.Read':true, 'dojo.data.api.Identity':true},
+       
+               _labelAttr: "label",
+               
+               constructor: function(/* Object */ params){
+                       dojo.mixin(this,params);
+               },
+               
+               getValue: function(/* item */ item, /* attribute-name-string */ attribute, /* value? */ defaultValue){
+                       //      According to the Read API comments in getValue() and exception is
+                       //      thrown when an item is not an item or the attribute not a string!
+                       this._assertIsItem(item);
+                       if (!dojo.isString(attribute)) {
+                               throw new Error(this._className+".getValue(): Invalid attribute, string expected!");
+                       }
+                       if(!this.hasAttribute(item, attribute)){
+                               // read api says: return defaultValue "only if *item* does not have a value for *attribute*." 
+                               // Is this the case here? The attribute doesn't exist, but a defaultValue, sounds reasonable.
+                               if(defaultValue){
+                                       return defaultValue;
+                               }
+                               console.log(this._className+".getValue(): Item does not have the attribute '"+attribute+"'.");
+                       }
+                       return item.i[attribute];
+               },
+               
+               getValues: function(/* item */ item, /* attribute-name-string */ attribute){
+                       this._assertIsItem(item);
+                       var ret = [];
+                       if(this.hasAttribute(item, attribute)){
+                               ret.push(item.i[attribute]);
+                       }
+                       return ret;
+               },
+               
+               getAttributes: function(/* item */ item){
+                       this._assertIsItem(item);
+                       var ret = [];
+                       for(var i in item.i){
+                               ret.push(i);
+                       }
+                       return ret;
+               },
+       
+               hasAttribute: function(/* item */ item, /* attribute-name-string */ attribute) {
+                       //      summary: 
+                       //              See dojo.data.api.Read.hasAttribute()
+                       return this.isItem(item) && typeof item.i[attribute]!="undefined";
+               },
+               
+               containsValue: function(/* item */ item, /* attribute-name-string */ attribute, /* anything */ value){
+                       var values = this.getValues(item, attribute);
+                       var len = values.length;
+                       for(var i=0; i<len; i++){
+                               if(values[i]==value){
+                                       return true;
+                               }
+                       }
+                       return false;
+               },
+               
+               isItem: function(/* anything */ something){
+                       // Some basic tests, that are quick and easy to do here.
+                       // >>> var store = new dojox.data.QueryReadStore({});
+                       // >>> store.isItem("");
+                       // false
+                       //
+                       // >>> var store = new dojox.data.QueryReadStore({});
+                       // >>> store.isItem({});
+                       // false
+                       //
+                       // >>> var store = new dojox.data.QueryReadStore({});
+                       // >>> store.isItem(0);
+                       // false
+                       //
+                       // >>> var store = new dojox.data.QueryReadStore({});
+                       // >>> store.isItem({name:"me", label:"me too"});
+                       // false
+                       //
+                       if(something){
+                               return typeof something.r!="undefined" && something.r==this;
+                       }
+                       return false;
+               },
+               
+               isItemLoaded: function(/* anything */ something) {
+                       // Currently we dont have any state that tells if an item is loaded or not
+                       // if the item exists its also loaded.
+                       // This might change when we start working with refs inside items ...
+                       return this.isItem(something);
+               },
+       
+               loadItem: function(/* object */ args){
+                       if(this.isItemLoaded(args.item)){
+                               return;
+                       }
+                       // Actually we have nothing to do here, or at least I dont know what to do here ...
+               },
+       
+               fetch:function(/* Object? */ request){
+                       //      summary:
+                       //              See dojo.data.util.simpleFetch.fetch() this is just a copy and I adjusted
+                       //              only the paging, since it happens on the server if doClientPaging is
+                       //              false, thx to http://trac.dojotoolkit.org/ticket/4761 reporting this.
+                       //              Would be nice to be able to use simpleFetch() to reduce copied code,
+                       //              but i dont know how yet. Ideas please!
+                       request = request || {};
+                       if(!request.store){
+                               request.store = this;
+                       }
+                       var self = this;
+               
+                       var _errorHandler = function(errorData, requestObject){
+                               if(requestObject.onError){
+                                       var scope = requestObject.scope || dojo.global;
+                                       requestObject.onError.call(scope, errorData, requestObject);
+                               }
+                       };
+               
+                       var _fetchHandler = function(items, requestObject, numRows){
+                               var oldAbortFunction = requestObject.abort || null;
+                               var aborted = false;
+                               
+                               var startIndex = requestObject.start?requestObject.start:0;
+                               if (self.doClientPaging==false) {
+                                       // For client paging we dont need no slicing of the result.
+                                       startIndex = 0;
+                               }
+                               var endIndex   = requestObject.count?(startIndex + requestObject.count):items.length;
+               
+                               requestObject.abort = function(){
+                                       aborted = true;
+                                       if(oldAbortFunction){
+                                               oldAbortFunction.call(requestObject);
+                                       }
+                               };
+               
+                               var scope = requestObject.scope || dojo.global;
+                               if(!requestObject.store){
+                                       requestObject.store = self;
+                               }
+                               if(requestObject.onBegin){
+                                       requestObject.onBegin.call(scope, numRows, requestObject);
+                               }
+                               if(requestObject.sort && this.doClientSorting){
+                                       items.sort(dojo.data.util.sorter.createSortFunction(requestObject.sort, self));
+                               }
+                               if(requestObject.onItem){
+                                       for(var i = startIndex; (i < items.length) && (i < endIndex); ++i){
+                                               var item = items[i];
+                                               if(!aborted){
+                                                       requestObject.onItem.call(scope, item, requestObject);
+                                               }
+                                       }
+                               }
+                               if(requestObject.onComplete && !aborted){
+                                       var subset = null;
+                                       if (!requestObject.onItem) {
+                                               subset = items.slice(startIndex, endIndex);
+                                       }
+                                       requestObject.onComplete.call(scope, subset, requestObject);   
+                               }
+                       };
+                       this._fetchItems(request, _fetchHandler, _errorHandler);
+                       return request; // Object
+               },
+       
+               getFeatures: function(){
+                       return this._features;
+               },
+       
+               close: function(/*dojo.data.api.Request || keywordArgs || null */ request){
+                       // I have no idea if this is really needed ... 
+               },
+       
+               getLabel: function(/* item */ item){
+                       //      summary:
+                       //              See dojo.data.api.Read.getLabel()
+                       if(this._labelAttr && this.isItem(item)){
+                               return this.getValue(item, this._labelAttr); //String
+                       }
+                       return undefined; //undefined
+               },
+       
+               getLabelAttributes: function(/* item */ item){
+                       //      summary:
+                       //              See dojo.data.api.Read.getLabelAttributes()
+                       if(this._labelAttr){
+                               return [this._labelAttr]; //array
+                       }
+                       return null; //null
+               },
+               
+               _fetchItems: function(request, fetchHandler, errorHandler){
+                       //      summary:
+                       //              The request contains the data as defined in the Read-API.
+                       //              Additionally there is following keyword "serverQuery".
+                       //
+                       //      The *serverQuery* parameter, optional.
+                       //              This parameter contains the data that will be sent to the server.
+                       //              If this parameter is not given the parameter "query"'s
+                       //              data are sent to the server. This is done for some reasons:
+                       //              - to specify explicitly which data are sent to the server, they
+                       //                might also be a mix of what is contained in "query", "queryOptions"
+                       //                and the paging parameters "start" and "count" or may be even
+                       //                completely different things.
+                       //              - don't modify the request.query data, so the interface using this
+                       //                store can rely on unmodified data, as the combobox dijit currently
+                       //                does it, it compares if the query has changed
+                       //              - request.query is required by the Read-API
+                       //
+                       //              I.e. the following examples might be sent via GET:
+                       //                fetch({query:{name:"abc"}, queryOptions:{ignoreCase:true}})
+                       //                the URL will become:   /url.php?name=abc
+                       //
+                       //                fetch({serverQuery:{q:"abc", c:true}, query:{name:"abc"}, queryOptions:{ignoreCase:true}})
+                       //                the URL will become:   /url.php?q=abc&c=true
+                       //                // The serverQuery-parameter has overruled the query-parameter
+                       //                // but the query parameter stays untouched, but is not sent to the server!
+                       //                // The serverQuery contains more data than the query, so they might differ!
+                       //
+       
+                       var serverQuery = request.serverQuery || request.query || {};
+                       //Need to add start and count
+                       if(!this.doClientPaging){
+                               serverQuery.start = request.start || 0;
+                               // Count might not be sent if not given.
+                               if (request.count) {
+                                       serverQuery.count = request.count;
+                               }
+                       }
+                       if(!this.doClientSorting){
+                               if(request.sort){
+                                       var sort = request.sort[0];
+                                       if(sort && sort.attribute){
+                                               var sortStr = sort.attribute;
+                                               if(sort.descending){
+                                                       sortStr = "-" + sortStr;
+                                               }
+                                               serverQuery.sort = sortStr;
+                                       }
+                               }
+                       }
+                       // Compare the last query and the current query by simply json-encoding them,
+                       // so we dont have to do any deep object compare ... is there some dojo.areObjectsEqual()???
+                       if(this.doClientPaging && this._lastServerQuery!==null &&
+                               dojo.toJson(serverQuery)==dojo.toJson(this._lastServerQuery)
+                               ){
+                               fetchHandler(this._items, request);
+                       }else{
+                               var xhrFunc = this.requestMethod.toLowerCase()=="post" ? dojo.xhrPost : dojo.xhrGet;
+                               var xhrHandler = xhrFunc({url:this.url, handleAs:"json-comment-optional", content:serverQuery});
+                               xhrHandler.addCallback(dojo.hitch(this, function(data){
+                                       data = this._filterResponse(data);
+                                       if (data.label){
+                                               this._labelAttr = data.label;
+                                       }
+                                       var numRows = data.numRows || -1;
+       
+                                       this._items = [];
+                                       // Store a ref to "this" in each item, so we can simply check if an item
+                                       // really origins form here (idea is from ItemFileReadStore, I just don't know
+                                       // how efficient the real storage use, garbage collection effort, etc. is).
+                                       dojo.forEach(data.items,function(e){ 
+                                               this._items.push({i:e, r:this}); 
+                                       },this); 
+                                       
+                                       var identifier = data.identifier;
+                                       this._itemsByIdentity = {};
+                                       if(identifier){
+                                               this._identifier = identifier;
+                                               for(i = 0; i < this._items.length; ++i){
+                                                       var item = this._items[i].i;
+                                                       var identity = item[identifier];
+                                                       if(!this._itemsByIdentity[identity]){
+                                                               this._itemsByIdentity[identity] = item;
+                                                       }else{
+                                                               throw new Error(this._className+":  The json data as specified by: [" + this.url + "] is malformed.  Items within the list have identifier: [" + identifier + "].  Value collided: [" + identity + "]");
+                                                       }
+                                               }
+                                       }else{
+                                               this._identifier = Number;
+                                               for(i = 0; i < this._items.length; ++i){
+                                                       this._items[i].n = i;
+                                               }
+                                       }
+                                       
+                                       // TODO actually we should do the same as dojo.data.ItemFileReadStore._getItemsFromLoadedData() to sanitize
+                                       // (does it really sanititze them) and store the data optimal. should we? for security reasons???
+                                       numRows = (numRows === -1) ? this._items.length : numRows;
+                                       fetchHandler(this._items, request, numRows);
+                               }));
+                               xhrHandler.addErrback(function(error){
+                                       errorHandler(error, request);
+                               });
+                               // Generate the hash using the time in milliseconds and a randon number.
+                               // Since Math.randon() returns something like: 0.23453463, we just remove the "0."
+                               // probably just for esthetic reasons :-).
+                               this.lastRequestHash = new Date().getTime()+"-"+String(Math.random()).substring(2);
+                               this._lastServerQuery = dojo.mixin({}, serverQuery);
+                       }
+               },
+               
+               _filterResponse: function(data){
+                       //      summary:
+                       //              If the data from servers needs to be processed before it can be processed by this
+                       //              store, then this function should be re-implemented in subclass. This default 
+                       //              implementation just return the data unchanged.
+                       //      data:
+                       //              The data received from server
+                       return data;
+               },
+       
+               _assertIsItem: function(/* item */ item){
+                       //      summary:
+                       //              It throws an error if item is not valid, so you can call it in every method that needs to
+                       //              throw an error when item is invalid.
+                       //      item: 
+                       //              The item to test for being contained by the store.
+                       if(!this.isItem(item)){
+                               throw new Error(this._className+": Invalid item argument.");
+                       }
+               },
+       
+               _assertIsAttribute: function(/* attribute-name-string */ attribute){
+                       //      summary:
+                       //              This function tests whether the item passed in is indeed a valid 'attribute' like type for the store.
+                       //      attribute: 
+                       //              The attribute to test for being contained by the store.
+                       if(typeof attribute !== "string"){ 
+                               throw new Error(this._className+": Invalid attribute argument ('"+attribute+"').");
+                       }
+               },
+       
+               fetchItemByIdentity: function(/* Object */ keywordArgs){
+                       //      summary: 
+                       //              See dojo.data.api.Identity.fetchItemByIdentity()
+       
+                       // See if we have already loaded the item with that id
+                       // In case there hasn't been a fetch yet, _itemsByIdentity is null
+                       // and thus a fetch will be triggered below.
+                       if(this._itemsByIdentity){
+                               var item = this._itemsByIdentity[keywordArgs.identity];
+                               if(!(item === undefined)){
+                                       if(keywordArgs.onItem){
+                                               var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
+                                               keywordArgs.onItem.call(scope, {i:item, r:this});
+                                       }
+                                       return;
+                               }
+                       }
+       
+                       // Otherwise we need to go remote
+                       // Set up error handler
+                       var _errorHandler = function(errorData, requestObject){
+                               var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
+                               if(keywordArgs.onError){
+                                       keywordArgs.onError.call(scope, error);
+                               }
+                       };
+                       
+                       // Set up fetch handler
+                       var _fetchHandler = function(items, requestObject){
+                               var scope =  keywordArgs.scope?keywordArgs.scope:dojo.global;
+                               try{
+                                       // There is supposed to be only one result
+                                       var item = null;
+                                       if(items && items.length == 1){
+                                               item = items[0];
+                                       }
+                                       
+                                       // If no item was found, item is still null and we'll
+                                       // fire the onItem event with the null here
+                                       if(keywordArgs.onItem){
+                                               keywordArgs.onItem.call(scope, item);
+                                       }
+                               }catch(error){
+                                       if(keywordArgs.onError){
+                                               keywordArgs.onError.call(scope, error);
+                                       }
+                               }
+                       };
+                       
+                       // Construct query
+                       var request = {serverQuery:{id:keywordArgs.identity}};
+                       
+                       // Dispatch query
+                       this._fetchItems(request, _fetchHandler, _errorHandler);
+               },
+               
+               getIdentity: function(/* item */ item){
+                       //      summary: 
+                       //              See dojo.data.api.Identity.getIdentity()
+                       var identifier = null;
+                       if(this._identifier === Number){
+                               identifier = item.n; // Number
+                       }else{
+                               identifier = item.i[this._identifier];
+                       }
+                       return identifier;
+               },
+               
+               getIdentityAttributes: function(/* item */ item){
+                       //      summary:
+                       //              See dojo.data.api.Identity.getIdentityAttributes()
+                       return [this._identifier];
+               }
+       }
+);
+
+}