SemanticScuttle/includes/js/dojox/rpc/JsonRestStore.js

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if(!dojo._hasResource["dojox.data.JsonRestStore"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojox.data.JsonRestStore"] = true;
dojo.provide("dojox.data.JsonRestStore");
dojo.require("dojox.rpc.Rest");
dojo.require("dojox.rpc.JsonReferencing"); // TODO: Make it work without this dependency
// A JsonRestStore takes a REST service and uses it the remote communication for a
// read/write dojo.data implementation. To use a JsonRestStore you should create a
// service with a REST transport. This can be configured with an SMD:
//{
// services: {
// jsonRestStore: {
// transport: "REST",
// envelope: "URL",
// target: "store.php",
// contentType:"application/json",
// parameters: [
// {name: "location", type: "string", optional: true}
// ]
// }
// }
//}
// The SMD can then be used to create service, and the service can be passed to a JsonRestStore. For example:
// var myServices = new dojox.rpc.Service(dojo.moduleUrl("dojox.rpc.tests.resources", "test.smd"));
// var jsonStore = new dojox.data.JsonRestStore({service:myServices.jsonRestStore});
//
// The JsonRestStore will then cause all saved modifications to be server using Rest commands (PUT, POST, or DELETE).
// The JsonRestStore also supports lazy loading. References can be made to objects that have not been loaded.
// For example if a service returned:
// {"name":"Example","lazyLoadedObject":{"$ref":"obj2"}}
//
// And this object has accessed using the dojo.data API:
// var obj = jsonStore.getValue(myObject,"lazyLoadedObject");
// The object would automatically be requested from the server (with an object id of "obj2").
//
// When using a Rest store on a public network, it is important to implement proper security measures to
// control access to resources
dojox.data.ASYNC_MODE = 0;
dojox.data.SYNC_MODE = 1;
dojo.declare("dojox.data.JsonRestStore",
null,
{
mode: dojox.data.ASYNC_MODE,
constructor: function(options){
//summary:
// JsonRestStore constructor, instantiate a new JsonRestStore
// A JsonRestStore can be configured from a JSON Schema. Queries are just
// passed through as URLs for XHR requests,
// so there is nothing to configure, just plug n play.
// Of course there are some options to fiddle with if you want:
//
// jsonSchema: /* object */
//
// service: /* function */
// This is the service object that is used to retrieve lazy data and save results
// The function should be directly callable with a single parameter of an object id to be loaded
// The function should also have the following methods:
// put(id,value) - puts the value at the given id
// post(id,value) - posts (appends) the value at the given id
// delete(id) - deletes the value corresponding to the given id
//
// idAttribute: /* string */
// Defaults to 'id'. The name of the attribute that holds an objects id.
// This can be a preexisting id provided by the server.
// If an ID isn't already provided when an object
// is fetched or added to the store, the autoIdentity system
// will generate an id for it and add it to the index.
// mode: dojox.data.ASYNC_MODE || dojox.data.SYNC_MODE
// Defaults to ASYNC_MODE. This option sets the default mode for this store.
// Sync calls return their data immediately from the calling function
// instead of calling the callback functions. Functions such as
// fetchItemByIdentity() and fetch() both accept a string parameter in addtion
// to the normal keywordArgs parameter. When passed this option, SYNC_MODE will
// automatically be used even when the default mode of the system is ASYNC_MODE.
// A normal request to fetch or fetchItemByIdentity (with kwArgs object) can also
// include a mode property to override this setting for that one request.
//setup a byId alias to the api call
this.byId=this.fetchItemByIdentity;
// if the advanced json parser is enabled, we can pass through object updates as onSet events
dojo.connect(dojox.rpc,"onUpdate",this,function(obj,attrName,oldValue,newValue){
var prefix = this.service.serviceName + '/';
if (!obj._id){
console.log("no id on updated object ", obj);
}
else if (obj._id.substring(0,prefix.length) == prefix)
this.onSet(obj,attrName,oldValue,newValue);
});
if (options){
dojo.mixin(this,options);
}
if (!this.service)
throw Error("A service is required for JsonRestStore");
if (!(this.service.contentType + '').match(/application\/json/))
throw Error("A service must use a contentType of 'application/json' in order to be used in a JsonRestStore");
this.idAttribute = (this.service._schema && this.service._schema._idAttr) || 'id';
var arrayModifyingMethodNames = ["splice","push","pop","unshift","shift","reverse","sort"];
this._arrayModifyingMethods = {};
var array = [];
var _this = this;
// setup array augmentation, for catching mods and setting arrays as dirty
for (var i = 0; i < arrayModifyingMethodNames.length; i++){
(function(key){ // closure for the method to be bound correctly
var method = array[key];
_this._arrayModifyingMethods[key] = function(){
_this._setDirty(this); // set the array as dirty before the native modifying operation
return method.apply(this,arguments);
}
_this._arrayModifyingMethods[key]._augmented = 1;
})(arrayModifyingMethodNames[i]);
}
this._deletedItems=[];
this._dirtyItems=[];
//given a url, load json data from as the store
},
_loadById: function(id,callback){
var slashIndex = id.indexOf('/');
var serviceName = id.substring(0,slashIndex);
var id = id.substring(slashIndex + 1);
(this.service.serviceName == serviceName ?
this.service : // use the current service if it is the right one
dojox.rpc.services[serviceName])(id) // otherwise call by looking up the service
.addCallback(callback);
},
getValue: function(item, property,lazyCallback){
// summary:
// Gets the value of an item's 'property'
//
// item: /* object */
// property: /* string */
// property to look up value for
// lazyCallback: /* function*/
// not part of the API, but if you are using lazy loading properties, you may provide a callback to resume, in order to have asynchronous loading
var value = item[property];
if (value && value.$ref){
dojox.rpc._sync = !lazyCallback; // tell the service to operate synchronously (I have some concerns about the "thread" safety with FF3, as I think it does event stacking on sync calls)
this._loadById((value && value._id) || (item._id + '.' + property),lazyCallback);
delete dojox.rpc._sync; // revert to normal async behavior
} else if (lazyCallback){lazyCallback(value);}
return value;
},
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 dojo.isArray(val) ? val : [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){
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 getValue(item,attribute)==value;
},
isItem: function(item){
// summary:
// Checks to see if a passed 'item'
// is really a JsonRestStore item.
//
// item: /* object */
// attribute: /* string */
return !!(dojo.isObject(item) && item._id);
},
isItemLoaded: function(item){
// summary:
// returns isItem() :)
//
// item: /* object */
return !item.$ref;
},
loadItem: function(item){
// summary:
// Loads an item that has not been loaded yet. Lazy loading should happen through getValue, and if used properly, this should never need to be called
// returns true. Note this does not work with lazy loaded primitives!
if (item.$ref){
dojox.rpc._sync = true; // tell the service to operate synchronously
this._loadById(item._id)
delete dojox.rpc._sync; // revert to normal async behavior
}
return true;
},
_walk : function(value,forEach){
// walk the graph, avoiding duplication
var walked=[];
function walk(value){
if (value && typeof value == 'object' && !value.__walked){
value.__walked = true;
walked.push(value);
for (var i in value){
if (walk(value[i])){
forEach(value,i,value[i]);
}
}
return true;
}
}
walk(value);
forEach({},null,value);
for (var i = 0; i < walked.length;i++)
delete walked[i].__walked;
},
fetch: function(args){
//console.log("fetch() ", args);
// summary
//
// fetch takes either a string argument or a keywordArgs
// object containing the parameters for the search.
// If passed a string, fetch will interpret this string
// as the query to be performed and will do so in
// SYNC_MODE returning the results immediately.
// If an object is supplied as 'args', its options will be
// parsed and then contained query executed.
//
// query: /* string or object */
// Defaults to "". This is basically passed to the XHR request as the URL to get the data
//
// start: /* int */
// Starting item in result set
//
// count: /* int */
// Maximum number of items to return
//
// cache: /* boolean */
//
// sort: /* function */
// Not Implemented yet
//
// The following only apply to ASYNC requests (the default)
//
// onBegin: /* function */
// called before any results are returned. Parameters
// will be the count and the original fetch request
//
// onItem: /*function*/
// called for each returned item. Parameters will be
// the item and the fetch request
//
// onComplete: /* function */
// called on completion of the request. Parameters will
// be the complete result set and the request
//
// onError: /* function */
// colled in the event of an error
if(dojo.isString(args)){
query = args;
args={query: query, mode: dojox.data.SYNC_MODE};
}
var query;
if (!args || !args.query){
if (!args){
var args={};
}
if (!args.query){
args.query="";
query=args.query;
}
}
if (dojo.isObject(args.query)){
if (args.query.query){
query = args.query.query;
}else{
query = args.query = "";
}
if (args.query.queryOptions){
args.queryOptions=args.query.queryOptions
}
}else{
query=args.query;
}
if (args.start || args.count){
query += '[' + (args.start ? args.start : '') + ':' + (args.count ? ((args.start || 0) + args.count) : '') + ']';
}
var results = dojox.rpc._index[this.service.serviceName + '/' + query];
if (!args.mode){args.mode = this.mode;}
var _this = this;
var defResult;
dojox.rpc._sync = this.mode;
dojox._newId = query;
if (results && !("cache" in args && !args.cache)){ // TODO: Add TTL maybe?
defResult = new dojo.Deferred;
defResult.callback(results);
}
else {
defResult = this.service(query);
}
defResult.addCallback(function(results){
delete dojox._newId; // cleanup
if (args.onBegin){
args["onBegin"].call(_this, results.length, args);
}
_this._walk(results,function(obj,i,value){
if (value instanceof Array){
for (var i in _this._arrayModifyingMethods){
if (!value[i]._augmented){
value[i] = _this._arrayModifyingMethods[i];
}
}
}
});
if (args.onItem){
for (var i=0; i<results.length;i++){
args["onItem"].call(_this, results[i], args);
}
}
if (args.onComplete){
args["onComplete"].call(_this, results, args);
}
return results;
});
defResult.addErrback(args.onError);
return args;
},
getFeatures: function(){
// summary:
// return the store feature set
return {
"dojo.data.api.Read": true,
"dojo.data.api.Identity": true,
"dojo.data.api.Write": true,
"dojo.data.api.Notification": true
}
},
getLabel: function(item){
// summary
// returns the label for an item. Just gets the "label" attribute.
//
return this.getValue(item,"label");
},
getLabelAttributes: function(item){
// summary:
// returns an array of attributes that are used to create the label of an item
return ["label"];
},
sort: function(a,b){
console.log("TODO::implement default sort algo");
},
//Identity API Support
getIdentity: function(item){
// summary
// returns the identity of an item or throws
// a not found error.
var prefix = this.service.serviceName + '/';
if (!item._id){// generate a good random id
item._id = prefix + Math.random().toString(16).substring(2,14)+Math.random().toString(16).substring(2,14);
}
if (item._id.substring(0,prefix.length) != prefix){
throw Error("Identity attribute not found");
}
return item._id.substring(prefix.length);
},
getIdentityAttributes: function(item){
// summary:
// returns the attributes which are used to make up the
// identity of an item. Basically returns this.idAttribute
return [this.idAttribute];
},
fetchItemByIdentity: function(args){
// summary:
// fetch an item by its identity. fetch and fetchItemByIdentity work exactly the same
return this.fetch(args);
},
//Write API Support
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.
// parentInfo:
// An optional javascript object defining what item is the parent of this item (in a hierarchical store. Not all stores do hierarchical items),
// and what attribute of that parent to assign the new item to. If this is present, and the attribute specified
// is a multi-valued attribute, it will append this item into the array of values for that attribute. The structure
// of the object is as follows:
// {
// parent: someItem,
// }
// or
// {
// parentId: someItemId,
// }
if (this.service._schema && this.service._schema.clazz && data.constructor != this.service._schema.clazz)
data = dojo.mixin(new this.service._schema.clazz,data);
this.getIdentity(data);
this._getParent(parentInfo).push(data); // essentially what newItem really means
this.onNew(data);
return data;
},
_getParent : function(parentInfo){
var parentId = (parentInfo && parentInfo.parentId) || this.parentId || '';
var parent = (parentInfo && parentInfo.parent) || dojox.rpc._index[this.service.serviceName + '/' + parentId] || [];
if (!parent._id){
parent._id = this.service.serviceName + '/' + parentId;
this._setDirty(parent); // set it dirty so it will be post
}
return parent;
},
deleteItem: function(item,/*array*/parentInfo){
// summary
// deletes item any references to that item from the store.
//
// item:
// item to delete
//
// removeFrom: This an item or items from which to remove references to this object. This store does not record references,
// so if this parameter the entire object graph from load items will be searched for references. Providing this parameter
// is vastly faster. An empty object or truthy primitive can be passed if no references need to be removed
// If the desire is to delete only one reference, unsetAttribute or
// setValue is the way to go.
if (this.isItem(item))
this._deletedItems.push(item);
var _this = this;
this._walk(((parentInfo || this.parentId) && this._getParent(parentInfo)) || dojox.rpc._index,function(obj,i,val){
if (obj[i] === item){ // find a reference to this object
if (_this.isItem(obj)){
if (isNaN(i) || !obj.splice){ // remove a property
_this.unsetAttribute(obj,i);
delete obj[i];
}
else {// remove an array entry
obj.splice(i,1);
}
}
}
});
this.onDelete(item);
},
_setDirty: function(item){
// summary:
// adds an item to the list of dirty items. This item
// contains a reference to the item itself as well as a
// cloned and trimmed version of old item for use with
// revert.
var i;
if (!item._id)
return;
//if an item is already in the list of dirty items, don't add it again
//or it will overwrite the premodification data set.
for (i=0; i<this._dirtyItems.length; i++){
if (item==this._dirtyItems[i].item){
return;
}
}
var old = item instanceof Array ? [] : {};
for (i in item)
if (item.hasOwnProperty(i))
old[i] = item[i];
this._dirtyItems.push({item: item, old: old});
},
setValue: function(item, attribute, value){
// summary:
// sets 'attribute' on 'item' to 'value'
var old = item[attribute];
if (old != value){
this._setDirty(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 (!dojo.isArray(values)){throw new Error("setValues expects to be passed an Array object as its value");}
this._setDirty(item);
var old = item[attribute];
item[attribute]=values;
this.onSet(item,attribute,old,values);
},
unsetAttribute: function(item, attribute){
// summary:
// unsets 'attribute' on 'item'
this._setDirty(item);
var old = item[attribute];
delete item[attribute];
this.onSet(item,attribute,old,undefined);
},
_commitAppend: function(listId,item){
return this.service.post(listId,item);
},
save: function(kwArgs){
// summary:
// Saves the dirty data using REST Ajax methods
var data = [];
var left = 0; // this is how many changes are remaining to be received from the server
var _this = this;
function finishOne(){
if (!(--left))
_this.onSave(data);
}
while (this._dirtyItems.length > 0){
var dirty = this._dirtyItems.pop();
var item = dirty.item;
var append = false;
left++;
var deferred;
if (item instanceof Array && dirty.old instanceof Array){
// see if we can just append the item with a post
append = true;
for (var i = 0, l = dirty.old.length; i < l; i++){
if (item[i] != dirty.old[i]){
append = false;
}
}
if (append){ // if we can, we will do posts to add from here
for (;i<item.length;i++){
deferred = this._commitAppend(this.getIdentity(item),item[i]);
deferred.addCallback(finishOne);
}
}
}
if (!append){
deferred = this.service.put(this.getIdentity(item),item);
deferred.addCallback(finishOne);
}
data.push(item);
}
while (this._deletedItems.length > 0){
left++;
this.service['delete'](this.getIdentity(this._deletedItems.pop())).addCallback(finishOne);
}
},
revert: function(){
// summary
// returns any modified data to its original state prior to a save();
while (this._dirtyItems.length>0){
var i;
var d = this._dirtyItems.pop();
for (i in d.old){
d.item[i] = d.old[i];
}
for (i in d.item){
if (!d.old.hasOwnProperty(i))
delete d.item[i]
}
}
this.onRevert();
},
isDirty: function(item){
// summary
// returns true if the item is marked as dirty.
for (var i=0, l=this._dirtyItems.length; i<l; i++){
if (this._dirtyItems[i]==item){return true};
}
},
//Notifcation Support
onSet: function(){
},
onNew: function(){
},
onDelete: function(){
},
onSave: function(items){
// summary:
// notification of the save event..not part of the notification api,
// but probably should be.
//console.log("onSave() ", items);
},
onRevert: function(){
// summary:
// notification of the revert event..not part of the notification api,
// but probably should be.
}
}
);
}