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ItemFileReadStore.js
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ItemFileReadStore.js
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if(!dojo._hasResource["dojo.data.ItemFileReadStore"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojo.data.ItemFileReadStore"] = true;
dojo.provide("dojo.data.ItemFileReadStore");
dojo.require("dojo.data.util.filter");
dojo.require("dojo.data.util.simpleFetch");
dojo.require("dojo.date.stamp");
dojo.declare("dojo.data.ItemFileReadStore", null,{
// summary:
// The ItemFileReadStore implements the dojo.data.api.Read API and reads
// data from JSON files that have contents in this format --
// { items: [
// { name:'Kermit', color:'green', age:12, friends:['Gonzo', {_reference:{name:'Fozzie Bear'}}]},
// { name:'Fozzie Bear', wears:['hat', 'tie']},
// { name:'Miss Piggy', pets:'Foo-Foo'}
// ]}
// Note that it can also contain an 'identifer' property that specified which attribute on the items
// in the array of items that acts as the unique identifier for that item.
//
constructor: function(/* Object */ keywordParameters){
// summary: constructor
// keywordParameters: {url: String}
// keywordParameters: {data: jsonObject}
// keywordParameters: {typeMap: object)
// The structure of the typeMap object is as follows:
// {
// type0: function || object,
// type1: function || object,
// ...
// typeN: function || object
// }
// Where if it is a function, it is assumed to be an object constructor that takes the
// value of _value as the initialization parameters. If it is an object, then it is assumed
// to be an object of general form:
// {
// type: function, //constructor.
// deserialize: function(value) //The function that parses the value and constructs the object defined by type appropriately.
// }
this._arrayOfAllItems = [];
this._arrayOfTopLevelItems = [];
this._loadFinished = false;
this._jsonFileUrl = keywordParameters.url;
this._jsonData = keywordParameters.data;
this._datatypeMap = keywordParameters.typeMap || {};
if(!this._datatypeMap['Date']){
//If no default mapping for dates, then set this as default.
//We use the dojo.date.stamp here because the ISO format is the 'dojo way'
//of generically representing dates.
this._datatypeMap['Date'] = {
type: Date,
deserialize: function(value){
return dojo.date.stamp.fromISOString(value);
}
};
}
this._features = {'dojo.data.api.Read':true, 'dojo.data.api.Identity':true};
this._itemsByIdentity = null;
this._storeRefPropName = "_S"; // Default name for the store reference to attach to every item.
this._itemNumPropName = "_0"; // Default Item Id for isItem to attach to every item.
this._rootItemPropName = "_RI"; // Default Item Id for isItem to attach to every item.
this._loadInProgress = false; //Got to track the initial load to prevent duelling loads of the dataset.
this._queuedFetches = [];
},
url: "", // use "" rather than undefined for the benefit of the parser (#3539)
_assertIsItem: function(/* item */ item){
// summary:
// This function tests whether the item passed in is indeed an item in the store.
// item:
// The item to test for being contained by the store.
if(!this.isItem(item)){
throw new Error("dojo.data.ItemFileReadStore: 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("dojo.data.ItemFileReadStore: Invalid attribute argument.");
}
},
getValue: function( /* item */ item,
/* attribute-name-string */ attribute,
/* value? */ defaultValue){
// summary:
// See dojo.data.api.Read.getValue()
var values = this.getValues(item, attribute);
return (values.length > 0)?values[0]:defaultValue; // mixed
},
getValues: function(/* item */ item,
/* attribute-name-string */ attribute){
// summary:
// See dojo.data.api.Read.getValues()
this._assertIsItem(item);
this._assertIsAttribute(attribute);
return item[attribute] || []; // Array
},
getAttributes: function(/* item */ item){
// summary:
// See dojo.data.api.Read.getAttributes()
this._assertIsItem(item);
var attributes = [];
for(var key in item){
// Save off only the real item attributes, not the special id marks for O(1) isItem.
if((key !== this._storeRefPropName) && (key !== this._itemNumPropName) && (key !== this._rootItemPropName)){
attributes.push(key);
}
}
return attributes; // Array
},
hasAttribute: function( /* item */ item,
/* attribute-name-string */ attribute) {
// summary:
// See dojo.data.api.Read.hasAttribute()
return this.getValues(item, attribute).length > 0;
},
containsValue: function(/* item */ item,
/* attribute-name-string */ attribute,
/* anything */ value){
// summary:
// See dojo.data.api.Read.containsValue()
var regexp = undefined;
if(typeof value === "string"){
regexp = dojo.data.util.filter.patternToRegExp(value, false);
}
return this._containsValue(item, attribute, value, regexp); //boolean.
},
_containsValue: function( /* item */ item,
/* attribute-name-string */ attribute,
/* anything */ value,
/* RegExp?*/ regexp){
// summary:
// Internal function for looking at the values contained by the item.
// description:
// Internal function for looking at the values contained by the item. This
// function allows for denoting if the comparison should be case sensitive for
// strings or not (for handling filtering cases where string case should not matter)
//
// item:
// The data item to examine for attribute values.
// attribute:
// The attribute to inspect.
// value:
// The value to match.
// regexp:
// Optional regular expression generated off value if value was of string type to handle wildcarding.
// If present and attribute values are string, then it can be used for comparison instead of 'value'
return dojo.some(this.getValues(item, attribute), function(possibleValue){
if(possibleValue !== null && !dojo.isObject(possibleValue) && regexp){
if(possibleValue.toString().match(regexp)){
return true; // Boolean
}
}else if(value === possibleValue){
return true; // Boolean
}
});
},
isItem: function(/* anything */ something){
// summary:
// See dojo.data.api.Read.isItem()
if(something && something[this._storeRefPropName] === this){
if(this._arrayOfAllItems[something[this._itemNumPropName]] === something){
return true;
}
}
return false; // Boolean
},
isItemLoaded: function(/* anything */ something){
// summary:
// See dojo.data.api.Read.isItemLoaded()
return this.isItem(something); //boolean
},
loadItem: function(/* object */ keywordArgs){
// summary:
// See dojo.data.api.Read.loadItem()
this._assertIsItem(keywordArgs.item);
},
getFeatures: function(){
// summary:
// See dojo.data.api.Read.getFeatures()
return this._features; //Object
},
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( /* Object */ keywordArgs,
/* Function */ findCallback,
/* Function */ errorCallback){
// summary:
// See dojo.data.util.simpleFetch.fetch()
var self = this;
var filter = function(requestArgs, arrayOfItems){
var items = [];
if(requestArgs.query){
var ignoreCase = requestArgs.queryOptions ? requestArgs.queryOptions.ignoreCase : false;
//See if there are any string values that can be regexp parsed first to avoid multiple regexp gens on the
//same value for each item examined. Much more efficient.
var regexpList = {};
for(var key in requestArgs.query){
var value = requestArgs.query[key];
if(typeof value === "string"){
regexpList[key] = dojo.data.util.filter.patternToRegExp(value, ignoreCase);
}
}
for(var i = 0; i < arrayOfItems.length; ++i){
var match = true;
var candidateItem = arrayOfItems[i];
if(candidateItem === null){
match = false;
}else{
for(var key in requestArgs.query) {
var value = requestArgs.query[key];
if (!self._containsValue(candidateItem, key, value, regexpList[key])){
match = false;
}
}
}
if(match){
items.push(candidateItem);
}
}
findCallback(items, requestArgs);
}else{
// We want a copy to pass back in case the parent wishes to sort the array.
// We shouldn't allow resort of the internal list, so that multiple callers
// can get lists and sort without affecting each other. We also need to
// filter out any null values that have been left as a result of deleteItem()
// calls in ItemFileWriteStore.
for(var i = 0; i < arrayOfItems.length; ++i){
var item = arrayOfItems[i];
if(item !== null){
items.push(item);
}
}
findCallback(items, requestArgs);
}
};
if(this._loadFinished){
filter(keywordArgs, this._getItemsArray(keywordArgs.queryOptions));
}else{
if(this._jsonFileUrl){
//If fetches come in before the loading has finished, but while
//a load is in progress, we have to defer the fetching to be
//invoked in the callback.
if(this._loadInProgress){
this._queuedFetches.push({args: keywordArgs, filter: filter});
}else{
this._loadInProgress = true;
var getArgs = {
url: self._jsonFileUrl,
handleAs: "json-comment-optional"
};
var getHandler = dojo.xhrGet(getArgs);
getHandler.addCallback(function(data){
try{
self._getItemsFromLoadedData(data);
self._loadFinished = true;
self._loadInProgress = false;
filter(keywordArgs, self._getItemsArray(keywordArgs.queryOptions));
self._handleQueuedFetches();
}catch(e){
self._loadFinished = true;
self._loadInProgress = false;
errorCallback(e, keywordArgs);
}
});
getHandler.addErrback(function(error){
self._loadInProgress = false;
errorCallback(error, keywordArgs);
});
}
}else if(this._jsonData){
try{
this._loadFinished = true;
this._getItemsFromLoadedData(this._jsonData);
this._jsonData = null;
filter(keywordArgs, this._getItemsArray(keywordArgs.queryOptions));
}catch(e){
errorCallback(e, keywordArgs);
}
}else{
errorCallback(new Error("dojo.data.ItemFileReadStore: No JSON source data was provided as either URL or a nested Javascript object."), keywordArgs);
}
}
},
_handleQueuedFetches: function(){
// summary:
// Internal function to execute delayed request in the store.
//Execute any deferred fetches now.
if (this._queuedFetches.length > 0) {
for(var i = 0; i < this._queuedFetches.length; i++){
var fData = this._queuedFetches[i];
var delayedQuery = fData.args;
var delayedFilter = fData.filter;
if(delayedFilter){
delayedFilter(delayedQuery, this._getItemsArray(delayedQuery.queryOptions));
}else{
this.fetchItemByIdentity(delayedQuery);
}
}
this._queuedFetches = [];
}
},
_getItemsArray: function(/*object?*/queryOptions){
// summary:
// Internal function to determine which list of items to search over.
// queryOptions: The query options parameter, if any.
if(queryOptions && queryOptions.deep) {
return this._arrayOfAllItems;
}
return this._arrayOfTopLevelItems;
},
close: function(/*dojo.data.api.Request || keywordArgs || null */ request){
// summary:
// See dojo.data.api.Read.close()
},
_getItemsFromLoadedData: function(/* Object */ dataObject){
// summary:
// Function to parse the loaded data into item format and build the internal items array.
// description:
// Function to parse the loaded data into item format and build the internal items array.
//
// dataObject:
// The JS data object containing the raw data to convery into item format.
//
// returns: array
// Array of items in store item format.
// First, we define a couple little utility functions...
function valueIsAnItem(/* anything */ aValue){
// summary:
// Given any sort of value that could be in the raw json data,
// return true if we should interpret the value as being an
// item itself, rather than a literal value or a reference.
// example:
// | false == valueIsAnItem("Kermit");
// | false == valueIsAnItem(42);
// | false == valueIsAnItem(new Date());
// | false == valueIsAnItem({_type:'Date', _value:'May 14, 1802'});
// | false == valueIsAnItem({_reference:'Kermit'});
// | true == valueIsAnItem({name:'Kermit', color:'green'});
// | true == valueIsAnItem({iggy:'pop'});
// | true == valueIsAnItem({foo:42});
var isItem = (
(aValue != null) &&
(typeof aValue == "object") &&
(!dojo.isArray(aValue)) &&
(!dojo.isFunction(aValue)) &&
(aValue.constructor == Object) &&
(typeof aValue._reference == "undefined") &&
(typeof aValue._type == "undefined") &&
(typeof aValue._value == "undefined")
);
return isItem;
}
var self = this;
function addItemAndSubItemsToArrayOfAllItems(/* Item */ anItem){
self._arrayOfAllItems.push(anItem);
for(var attribute in anItem){
var valueForAttribute = anItem[attribute];
if(valueForAttribute){
if(dojo.isArray(valueForAttribute)){
var valueArray = valueForAttribute;
for(var k = 0; k < valueArray.length; ++k){
var singleValue = valueArray[k];
if(valueIsAnItem(singleValue)){
addItemAndSubItemsToArrayOfAllItems(singleValue);
}
}
}else{
if(valueIsAnItem(valueForAttribute)){
addItemAndSubItemsToArrayOfAllItems(valueForAttribute);
}
}
}
}
}
this._labelAttr = dataObject.label;
// We need to do some transformations to convert the data structure
// that we read from the file into a format that will be convenient
// to work with in memory.
// Step 1: Walk through the object hierarchy and build a list of all items
var i;
var item;
this._arrayOfAllItems = [];
this._arrayOfTopLevelItems = dataObject.items;
for(i = 0; i < this._arrayOfTopLevelItems.length; ++i){
item = this._arrayOfTopLevelItems[i];
addItemAndSubItemsToArrayOfAllItems(item);
item[this._rootItemPropName]=true;
}
// Step 2: Walk through all the attribute values of all the items,
// and replace single values with arrays. For example, we change this:
// { name:'Miss Piggy', pets:'Foo-Foo'}
// into this:
// { name:['Miss Piggy'], pets:['Foo-Foo']}
//
// We also store the attribute names so we can validate our store
// reference and item id special properties for the O(1) isItem
var allAttributeNames = {};
var key;
for(i = 0; i < this._arrayOfAllItems.length; ++i){
item = this._arrayOfAllItems[i];
for(key in item){
if (key !== this._rootItemPropName)
{
var value = item[key];
if(value !== null){
if(!dojo.isArray(value)){
item[key] = [value];
}
}else{
item[key] = [null];
}
}
allAttributeNames[key]=key;
}
}
// Step 3: Build unique property names to use for the _storeRefPropName and _itemNumPropName
// This should go really fast, it will generally never even run the loop.
while(allAttributeNames[this._storeRefPropName]){
this._storeRefPropName += "_";
}
while(allAttributeNames[this._itemNumPropName]){
this._itemNumPropName += "_";
}
// Step 4: Some data files specify an optional 'identifier', which is
// the name of an attribute that holds the identity of each item.
// If this data file specified an identifier attribute, then build a
// hash table of items keyed by the identity of the items.
var arrayOfValues;
var identifier = dataObject.identifier;
if(identifier){
this._itemsByIdentity = {};
this._features['dojo.data.api.Identity'] = identifier;
for(i = 0; i < this._arrayOfAllItems.length; ++i){
item = this._arrayOfAllItems[i];
arrayOfValues = item[identifier];
var identity = arrayOfValues[0];
if(!this._itemsByIdentity[identity]){
this._itemsByIdentity[identity] = item;
}else{
if(this._jsonFileUrl){
throw new Error("dojo.data.ItemFileReadStore: The json data as specified by: [" + this._jsonFileUrl + "] is malformed. Items within the list have identifier: [" + identifier + "]. Value collided: [" + identity + "]");
}else if(this._jsonData){
throw new Error("dojo.data.ItemFileReadStore: The json data provided by the creation arguments is malformed. Items within the list have identifier: [" + identifier + "]. Value collided: [" + identity + "]");
}
}
}
}else{
this._features['dojo.data.api.Identity'] = Number;
}
// Step 5: Walk through all the items, and set each item's properties
// for _storeRefPropName and _itemNumPropName, so that store.isItem() will return true.
for(i = 0; i < this._arrayOfAllItems.length; ++i){
item = this._arrayOfAllItems[i];
item[this._storeRefPropName] = this;
item[this._itemNumPropName] = i;
}
// Step 6: We walk through all the attribute values of all the items,
// looking for type/value literals and item-references.
//
// We replace item-references with pointers to items. For example, we change:
// { name:['Kermit'], friends:[{_reference:{name:'Miss Piggy'}}] }
// into this:
// { name:['Kermit'], friends:[miss_piggy] }
// (where miss_piggy is the object representing the 'Miss Piggy' item).
//
// We replace type/value pairs with typed-literals. For example, we change:
// { name:['Nelson Mandela'], born:[{_type:'Date', _value:'July 18, 1918'}] }
// into this:
// { name:['Kermit'], born:(new Date('July 18, 1918')) }
//
// We also generate the associate map for all items for the O(1) isItem function.
for(i = 0; i < this._arrayOfAllItems.length; ++i){
item = this._arrayOfAllItems[i]; // example: { name:['Kermit'], friends:[{_reference:{name:'Miss Piggy'}}] }
for(key in item){
arrayOfValues = item[key]; // example: [{_reference:{name:'Miss Piggy'}}]
for(var j = 0; j < arrayOfValues.length; ++j) {
value = arrayOfValues[j]; // example: {_reference:{name:'Miss Piggy'}}
if(value !== null && typeof value == "object"){
if(value._type && value._value){
var type = value._type; // examples: 'Date', 'Color', or 'ComplexNumber'
var mappingObj = this._datatypeMap[type]; // examples: Date, dojo.Color, foo.math.ComplexNumber, {type: dojo.Color, deserialize(value){ return new dojo.Color(value)}}
if(!mappingObj){
throw new Error("dojo.data.ItemFileReadStore: in the typeMap constructor arg, no object class was specified for the datatype '" + type + "'");
}else if(dojo.isFunction(mappingObj)){
arrayOfValues[j] = new mappingObj(value._value);
}else if(dojo.isFunction(mappingObj.deserialize)){
arrayOfValues[j] = mappingObj.deserialize(value._value);
}else{
throw new Error("dojo.data.ItemFileReadStore: Value provided in typeMap was neither a constructor, nor a an object with a deserialize function");
}
}
if(value._reference){
var referenceDescription = value._reference; // example: {name:'Miss Piggy'}
if(dojo.isString(referenceDescription)){
// example: 'Miss Piggy'
// from an item like: { name:['Kermit'], friends:[{_reference:'Miss Piggy'}]}
arrayOfValues[j] = this._itemsByIdentity[referenceDescription];
}else{
// example: {name:'Miss Piggy'}
// from an item like: { name:['Kermit'], friends:[{_reference:{name:'Miss Piggy'}}] }
for(var k = 0; k < this._arrayOfAllItems.length; ++k){
var candidateItem = this._arrayOfAllItems[k];
var found = true;
for(var refKey in referenceDescription){
if(candidateItem[refKey] != referenceDescription[refKey]){
found = false;
}
}
if(found){
arrayOfValues[j] = candidateItem;
}
}
}
}
}
}
}
}
},
getIdentity: function(/* item */ item){
// summary:
// See dojo.data.api.Identity.getIdentity()
var identifier = this._features['dojo.data.api.Identity'];
if(identifier === Number){
return item[this._itemNumPropName]; // Number
}else{
var arrayOfValues = item[identifier];
if(arrayOfValues){
return arrayOfValues[0]; // Object || String
}
}
return null; // null
},
fetchItemByIdentity: function(/* Object */ keywordArgs){
// summary:
// See dojo.data.api.Identity.fetchItemByIdentity()
// Hasn't loaded yet, we have to trigger the load.
if(!this._loadFinished){
var self = this;
if(this._jsonFileUrl){
if(this._loadInProgress){
this._queuedFetches.push({args: keywordArgs});
}else{
this._loadInProgress = true;
var getArgs = {
url: self._jsonFileUrl,
handleAs: "json-comment-optional"
};
var getHandler = dojo.xhrGet(getArgs);
getHandler.addCallback(function(data){
var scope = keywordArgs.scope?keywordArgs.scope:dojo.global;
try{
self._getItemsFromLoadedData(data);
self._loadFinished = true;
self._loadInProgress = false;
var item = self._getItemByIdentity(keywordArgs.identity);
if(keywordArgs.onItem){
keywordArgs.onItem.call(scope, item);
}
self._handleQueuedFetches();
}catch(error){
self._loadInProgress = false;
if(keywordArgs.onError){
keywordArgs.onError.call(scope, error);
}
}
});
getHandler.addErrback(function(error){
self._loadInProgress = false;
if(keywordArgs.onError){
var scope = keywordArgs.scope?keywordArgs.scope:dojo.global;
keywordArgs.onError.call(scope, error);
}
});
}
}else if(this._jsonData){
// Passed in data, no need to xhr.
self._getItemsFromLoadedData(self._jsonData);
self._jsonData = null;
self._loadFinished = true;
var item = self._getItemByIdentity(keywordArgs.identity);
if(keywordArgs.onItem){
var scope = keywordArgs.scope?keywordArgs.scope:dojo.global;
keywordArgs.onItem.call(scope, item);
}
}
}else{
// Already loaded. We can just look it up and call back.
var item = this._getItemByIdentity(keywordArgs.identity);
if(keywordArgs.onItem){
var scope = keywordArgs.scope?keywordArgs.scope:dojo.global;
keywordArgs.onItem.call(scope, item);
}
}
},
_getItemByIdentity: function(/* Object */ identity){
// summary:
// Internal function to look an item up by its identity map.
var item = null;
if(this._itemsByIdentity){
item = this._itemsByIdentity[identity];
}else{
item = this._arrayOfAllItems[identity];
}
if(item === undefined){
item = null;
}
return item; // Object
},
getIdentityAttributes: function(/* item */ item){
// summary:
// See dojo.data.api.Identity.getIdentifierAttributes()
var identifier = this._features['dojo.data.api.Identity'];
if(identifier === Number){
// If (identifier === Number) it means getIdentity() just returns
// an integer item-number for each item. The dojo.data.api.Identity
// spec says we need to return null if the identity is not composed
// of attributes
return null; // null
}else{
return [identifier]; // Array
}
},
_forceLoad: function(){
// summary:
// Internal function to force a load of the store if it hasn't occurred yet. This is required
// for specific functions to work properly.
var self = this;
if(this._jsonFileUrl){
var getArgs = {
url: self._jsonFileUrl,
handleAs: "json-comment-optional",
sync: true
};
var getHandler = dojo.xhrGet(getArgs);
getHandler.addCallback(function(data){
try{
//Check to be sure there wasn't another load going on concurrently
//So we don't clobber data that comes in on it. If there is a load going on
//then do not save this data. It will potentially clobber current data.
//We mainly wanted to sync/wait here.
//TODO: Revisit the loading scheme of this store to improve multi-initial
//request handling.
if (self._loadInProgress !== true && !self._loadFinished) {
self._getItemsFromLoadedData(data);
self._loadFinished = true;
}
}catch(e){
console.log(e);
throw e;
}
});
getHandler.addErrback(function(error){
throw error;
});
}else if(this._jsonData){
self._getItemsFromLoadedData(self._jsonData);
self._jsonData = null;
self._loadFinished = true;
}
}
});
//Mix in the simple fetch implementation to this class.
dojo.extend(dojo.data.ItemFileReadStore,dojo.data.util.simpleFetch);
}

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