source: Dev/trunk/src/client/dojox/data/CssRuleStore.js

define(["dojo/_base/lang", "dojo/_base/declare", "dojo/_base/array", "dojo/_base/json","dojo/_base/kernel", "dojo/_base/sniff", "dojo/data/util/sorter", "dojo/data/util/filter", "./css"],
 function(lang, declare, array, jsonUtil, kernel, has, sorter, filter, css) {

return declare("dojox.data.CssRuleStore", null, {
        // summary:
        //              Basic store to display CSS information.
        // description:
        //              The CssRuleStore allows users to get information about active CSS rules in the page running the CssRuleStore.
        //              It can also filter out rules from specific stylesheets.  The attributes it exposes on rules are as follows:
        //
        //              - selector:                             The selector text.
        //              - classes:                              An array of classes present in this selector.
        //              - rule:                                 The actual DOM Rule object.
        //              - style:                                        The actual DOM CSSStyleDeclaration object.
        //              - cssText:                              The cssText string provided on the rule object.
        //              - styleSheet:                           The originating DOM Stylesheet object.
        //              - parentStyleSheet:             The parent stylesheet to the sheet this rule originates from.
        //              - parentStyleSheetHref: The href of the parent stylesheet.
        //
        //              AND every style attribute denoted as style.*, such as style.textAlign or style.backgroundColor

        _storeRef: '_S',
        _labelAttribute: 'selector', // text representation of the Item [label and identifier may need to stay due to method names]

        _cache: null,

        _browserMap: null,

        _cName: "dojox.data.CssRuleStore",

        constructor: function(/* Object */ keywordParameters){
                // Initializes this store
                if(keywordParameters){
                        lang.mixin(this, keywordParameters);
                }
                this._cache = {};
                this._allItems = null;
                this._waiting = [];
                this.gatherHandle = null;
                var self = this;
                // CSS files may not be finished loading by the time the store is constructed.  We need to
                // give them a little time, so setting the stylesheet loading to retry every 250ms.
                function gatherRules(){
                        try{
                                // Funkiness here is due to css that may still be loading.  This throws an DOM Access
                                // error if css isnt completely loaded.
                                self.context = css.determineContext(self.context);
                                if(self.gatherHandle){
                                        clearInterval(self.gatherHandle);
                                        self.gatherHandle = null;
                                }
                                // Handle any fetches that have been queued while we've been waiting on the CSS files
                                // to finish
                                while(self._waiting.length){
                                        var item = self._waiting.pop();
                                        css.rules.forEach(item.forFunc, null, self.context);
                                        item.finishFunc();
                                }
                        }catch(e){}
                }
                this.gatherHandle = setInterval(gatherRules,250);
        },
        
        setContext: function(/* Array */ context){
                // Sets the context in which queries are executed
                // context: Array - Array of CSS string paths to execute queries within
                if(context){
                        this.close();
                        this.context = css.determineContext(context);
                }
        },

        getFeatures: function(){
                // summary:
                //              See dojo/data/api/Read.getFeatures()
                return {
                        "dojo.data.api.Read" : true
                };
        },

        isItem: function(item){
                // summary:
                //              See dojo/data/api/Read.isItem()
                if(item && item[this._storeRef] == this){
                        return true;
                }
                return false;
        },

        hasAttribute: function(item, attribute){
                // summary:
                //              See dojo/data/api/Read.hasAttribute()
                this._assertIsItem(item);
                this._assertIsAttribute(attribute);
                var attrs = this.getAttributes(item);
                if(array.indexOf(attrs, attribute) != -1){
                        return true;
                }
                return false;
        },

        getAttributes: function(item){
                // summary:
                //              See dojo/data/api/Read.getAttributes()
                this._assertIsItem(item);
                var attrs = ['selector', 'classes', 'rule', 'style', 'cssText', 'styleSheet', 'parentStyleSheet', 'parentStyleSheetHref'];
                var style = item.rule.style;
                if(style){
                        var key;
                        for(key in style){
                                attrs.push("style." + key);
                        }
                }
                return attrs;
        },

        getValue: function(item, attribute, defaultValue){
                // summary:
                //              See dojo/data/api/Read.getValue()
                var values = this.getValues(item, attribute);
                var value = defaultValue;
                if(values && values.length > 0){
                        return values[0];
                }
                return defaultValue;
        },

        getValues: function(item, attribute){
                // summary:
                //              See dojo/data/api/Read.getValues()
                this._assertIsItem(item);
                this._assertIsAttribute(attribute);
                var value = null;
                if(attribute === "selector"){
                        value = item.rule["selectorText"];
                        if(value && lang.isString(value)){
                                value = value.split(",");
                        }
                }else if(attribute === "classes"){
                        value = item.classes;
                }else if(attribute === "rule"){
                        value = item.rule.rule;
                }else if(attribute === "style"){
                        value = item.rule.style;
                }else if(attribute === "cssText"){
                        if(has("ie")){
                                if(item.rule.style){
                                        value = item.rule.style.cssText;
                                        if(value){
                                                value = "{ " + value.toLowerCase() + " }";
                                        }
                                }
                        }else{
                                value = item.rule.cssText;
                                if(value){
                                        value = value.substring(value.indexOf("{"), value.length);
                                }
                        }
                }else if(attribute === "styleSheet"){
                        value = item.rule.styleSheet;
                }else if(attribute === "parentStyleSheet"){
                        value = item.rule.parentStyleSheet;
                }else if(attribute === "parentStyleSheetHref"){
                        if(item.href){
                                value = item.href;
                        }
                }else if(attribute.indexOf("style.") === 0){
                        var attr = attribute.substring(attribute.indexOf("."), attribute.length);
                        value = item.rule.style[attr];
                }else{
                        value = [];
                }
                if(value !== undefined){
                        if(!lang.isArray(value)){
                                value = [value];
                        }
                }
                return value;
        },

        getLabel: function(item){
                // summary:
                //              See dojo/data/api/Read.getLabel()
                this._assertIsItem(item);
                return this.getValue(item, this._labelAttribute);
        },

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

        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 = filter.patternToRegExp(value, false);
                }
                return this._containsValue(item, attribute, value, regexp); //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);
        },

        fetch: function(request){
                // summary:
                //              See dojo/data/api/Read.fetch()
                request = request || {};
                if(!request.store){
                        request.store = this;
                }

                var scope = request.scope || kernel.global;
                if(this._pending && this._pending.length > 0){
                        this._pending.push({request: request, fetch: true});
                }else{
                        this._pending = [{request: request, fetch: true}];
                        this._fetch(request);
                }
                return request;
        },

        _fetch: function(request){
                // summary:
                //              Populates the _allItems object with unique class names
                var scope = request.scope || kernel.global;
                if(this._allItems === null){
                        this._allItems = {};
                        try{
                                if(this.gatherHandle){
                                        this._waiting.push({'forFunc': lang.hitch(this, this._handleRule), 'finishFunc': lang.hitch(this, this._handleReturn)});
                                }else{
                                        css.rules.forEach(lang.hitch(this, this._handleRule), null, this.context);
                                        this._handleReturn();
                                }
                        }catch(e){
                                if(request.onError){
                                        request.onError.call(scope, e, request);
                                }
                        }
                }else{
                        this._handleReturn();
                }
        },

        _handleRule: function(rule, styleSheet, href){
                // summary:
                //              Handles the creation of an item based on the passed rule.  In this store, this implies
                //              parsing out all available class names.
                var selector = rule['selectorText'];
                var s = selector.split(" ");
                var classes = [];
                for(var j=0; j<s.length; j++){
                        var tmp = s[j];
                        var first = tmp.indexOf('.');
                        if(tmp && tmp.length > 0 && first !== -1){
                                var last = tmp.indexOf(',') || tmp.indexOf('[');
                                tmp = tmp.substring(first, ((last !== -1 && last > first)?last:tmp.length));
                                classes.push(tmp);
                        }
                }
                var item = {};
                item.rule = rule;
                item.styleSheet = styleSheet;
                item.href = href;
                item.classes = classes;
                item[this._storeRef] = this;
                if(!this._allItems[selector]){
                        this._allItems[selector] = [];
                }
                this._allItems[selector].push(item);
        },

        _handleReturn: function(){
                // summary:
                //              Handles the return from a fetching action.  Delegates requests to act on the resulting
                //              item set to eitehr the _handleFetchReturn or _handleFetchByIdentityReturn depending on
                //              where the request originated.
                var _inProgress = [];
                
                var items = [];
                var item = null;
                for(var i in this._allItems){
                        item = this._allItems[i];
                        for(var j in item){
                                items.push(item[j]);
                        }
                }

                var requestInfo;
                // One-level deep clone (can't use dojo.clone, since we don't want to clone all those store refs!)
                while(this._pending.length){
                        requestInfo = this._pending.pop();
                        requestInfo.request._items = items;
                        _inProgress.push(requestInfo);
                }

                while(_inProgress.length){
                        requestInfo = _inProgress.pop();
                        this._handleFetchReturn(requestInfo.request);
                }
        },

        _handleFetchReturn: function(/*Request */ request){
                // summary:
                //              Handles a fetchByIdentity request by finding the correct items.
                var scope = request.scope || kernel.global;
                var items = [];
                //Check to see if we've looked this query up before
                //If so, just reuse it, much faster.  Only regen if query changes.
                var cacheKey = "all";
                var i;
                if(request.query){
                        cacheKey = jsonUtil.toJson(request.query);
                }
                if(this._cache[cacheKey]){
                        items = this._cache[cacheKey];
                }else if(request.query){
                        for(i in request._items){
                                var item = request._items[i];
                                // Per https://bugs.webkit.org/show_bug.cgi?id=17935 , Safari 3.x always returns the selectorText
                                // of a rule in full lowercase.
                                var ignoreCase = (request.queryOptions ? request.queryOptions.ignoreCase : false);
                                var regexpList = {};
                                var key;
                                var value;
                                for(key in request.query){
                                        value = request.query[key];
                                        if(typeof value === "string"){
                                                regexpList[key] = filter.patternToRegExp(value, ignoreCase);
                                        }
                                }
                                var match = true;
                                for(key in request.query){
                                        value = request.query[key];
                                        if(!this._containsValue(item, key, value, regexpList[key])){
                                                match = false;
                                        }
                                }
                                if(match){
                                        items.push(item);
                                }
                        }
                        this._cache[cacheKey] = items;
                }else{
                        for(i in request._items){
                                items.push(request._items[i]);
                        }
                }
                var total = items.length;

                //Sort it if we need to.
                if(request.sort){
                        items.sort(sorter.createSortFunction(request.sort, this));
                }
                var start = 0;
                var count = items.length;
                if(request.start > 0 && request.start < items.length){
                        start = request.start;
                }
                if(request.count && request.count){
                        count = request.count;
                }
                var endIdx = start + count;
                if(endIdx > items.length){
                        endIdx = items.length;
                }

                items = items.slice(start, endIdx);

                if(request.onBegin){
                        request.onBegin.call(scope, total, request);
                }
                if(request.onItem){
                        if(lang.isArray(items)){
                                for(i = 0; i < items.length; i++){
                                        request.onItem.call(scope, items[i], request);
                                }
                                if(request.onComplete){
                                        request.onComplete.call(scope, null, request);
                                }
                        }
                }else if(request.onComplete){
                        request.onComplete.call(scope, items, request);
                }
                return request;
        },

        close: function(){
                // summary:
                //              See dojo/data/api/Read.close().
                //              Clears out the cache and allItems objects, meaning all future fetches will requery
                //              the stylesheets.
                this._cache = {};
                this._allItems = null;
        },
        
        _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(this._cName + ": 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._cName + ": Invalid attribute argument.");
                }
        },

        _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 array.some(this.getValues(item, attribute), function(possibleValue){
                        if(possibleValue !== null && !lang.isObject(possibleValue) && regexp){
                                if(possibleValue.toString().match(regexp)){
                                        return true; // Boolean
                                }
                        }else if(value === possibleValue){
                                return true; // Boolean
                        }
                        return false;
                });
        }
});
});