| // Copyright 2006 Google Inc. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or |
| // implied. See the License for the specific language governing |
| // permissions and limitations under the License. |
| /** |
| * Author: Steffen Meschkat <mesch@google.com> |
| * |
| * @fileoverview A simple formatter to project JavaScript data into |
| * HTML templates. The template is edited in place. I.e. in order to |
| * instantiate a template, clone it from the DOM first, and then |
| * process the cloned template. This allows for updating of templates: |
| * If the templates is processed again, changed values are merely |
| * updated. |
| * |
| * NOTE(mesch): IE DOM doesn't have importNode(). |
| * |
| * NOTE(mesch): The property name "length" must not be used in input |
| * data, see comment in jstSelect_(). |
| */ |
| |
| |
| /** |
| * Names of jstemplate attributes. These attributes are attached to |
| * normal HTML elements and bind expression context data to the HTML |
| * fragment that is used as template. |
| */ |
| var ATT_select = 'jsselect'; |
| var ATT_instance = 'jsinstance'; |
| var ATT_display = 'jsdisplay'; |
| var ATT_values = 'jsvalues'; |
| var ATT_vars = 'jsvars'; |
| var ATT_eval = 'jseval'; |
| var ATT_transclude = 'transclude'; |
| var ATT_content = 'jscontent'; |
| var ATT_skip = 'jsskip'; |
| |
| |
| /** |
| * Name of the attribute that caches a reference to the parsed |
| * template processing attribute values on a template node. |
| */ |
| var ATT_jstcache = 'jstcache'; |
| |
| |
| /** |
| * Name of the property that caches the parsed template processing |
| * attribute values on a template node. |
| */ |
| var PROP_jstcache = '__jstcache'; |
| |
| |
| /** |
| * ID of the element that contains dynamically loaded jstemplates. |
| */ |
| var STRING_jsts = 'jsts'; |
| |
| |
| /** |
| * Un-inlined string literals, to avoid object creation in |
| * IE6. |
| */ |
| var CHAR_asterisk = '*'; |
| var CHAR_dollar = '$'; |
| var CHAR_period = '.'; |
| var CHAR_ampersand = '&'; |
| var STRING_div = 'div'; |
| var STRING_id = 'id'; |
| var STRING_asteriskzero = '*0'; |
| var STRING_zero = '0'; |
| |
| |
| /** |
| * HTML template processor. Data values are bound to HTML templates |
| * using the attributes transclude, jsselect, jsdisplay, jscontent, |
| * jsvalues. The template is modifed in place. The values of those |
| * attributes are JavaScript expressions that are evaluated in the |
| * context of the data object fragment. |
| * |
| * @param {JsEvalContext} context Context created from the input data |
| * object. |
| * |
| * @param {Element} template DOM node of the template. This will be |
| * processed in place. After processing, it will still be a valid |
| * template that, if processed again with the same data, will remain |
| * unchanged. |
| * |
| * @param {boolean} opt_debugging Optional flag to collect debugging |
| * information while processing the template. Only takes effect |
| * in MAPS_DEBUG. |
| */ |
| function jstProcess(context, template, opt_debugging) { |
| var processor = new JstProcessor; |
| JstProcessor.prepareTemplate_(template); |
| |
| /** |
| * Caches the document of the template node, so we don't have to |
| * access it through ownerDocument. |
| * @type Document |
| */ |
| processor.document_ = ownerDocument(template); |
| |
| processor.run_(bindFully(processor, processor.jstProcessOuter_, |
| context, template)); |
| } |
| |
| |
| /** |
| * Internal class used by jstemplates to maintain context. This is |
| * necessary to process deep templates in Safari which has a |
| * relatively shallow maximum recursion depth of 100. |
| * @class |
| * @constructor |
| */ |
| function JstProcessor() { |
| } |
| |
| |
| /** |
| * Counter to generate node ids. These ids will be stored in |
| * ATT_jstcache and be used to lookup the preprocessed js attributes |
| * from the jstcache_. The id is stored in an attribute so it |
| * suvives cloneNode() and thus cloned template nodes can share the |
| * same cache entry. |
| * @type number |
| */ |
| JstProcessor.jstid_ = 0; |
| |
| |
| /** |
| * Map from jstid to processed js attributes. |
| * @type Object |
| */ |
| JstProcessor.jstcache_ = {}; |
| |
| /** |
| * The neutral cache entry. Used for all nodes that don't have any |
| * jst attributes. We still set the jsid attribute on those nodes so |
| * we can avoid to look again for all the other jst attributes that |
| * aren't there. Remember: not only the processing of the js |
| * attribute values is expensive and we thus want to cache it. The |
| * access to the attributes on the Node in the first place is |
| * expensive too. |
| */ |
| JstProcessor.jstcache_[0] = {}; |
| |
| |
| /** |
| * Map from concatenated attribute string to jstid. |
| * The key is the concatenation of all jst atributes found on a node |
| * formatted as "name1=value1&name2=value2&...", in the order defined by |
| * JST_ATTRIBUTES. The value is the id of the jstcache_ entry that can |
| * be used for this node. This allows the reuse of cache entries in cases |
| * when a cached entry already exists for a given combination of attribute |
| * values. (For example when two different nodes in a template share the same |
| * JST attributes.) |
| * @type Object |
| */ |
| JstProcessor.jstcacheattributes_ = {}; |
| |
| |
| /** |
| * Map for storing temporary attribute values in prepareNode_() so they don't |
| * have to be retrieved twice. (IE6 perf) |
| * @type Object |
| */ |
| JstProcessor.attributeValues_ = {}; |
| |
| |
| /** |
| * A list for storing non-empty attributes found on a node in prepareNode_(). |
| * The array is global since it can be reused - this way there is no need to |
| * construct a new array object for each invocation. (IE6 perf) |
| * @type Array |
| */ |
| JstProcessor.attributeList_ = []; |
| |
| |
| /** |
| * Prepares the template: preprocesses all jstemplate attributes. |
| * |
| * @param {Element} template |
| */ |
| JstProcessor.prepareTemplate_ = function(template) { |
| if (!template[PROP_jstcache]) { |
| domTraverseElements(template, function(node) { |
| JstProcessor.prepareNode_(node); |
| }); |
| } |
| }; |
| |
| |
| /** |
| * A list of attributes we use to specify jst processing instructions, |
| * and the functions used to parse their values. |
| * |
| * @type Array.<Array> |
| */ |
| var JST_ATTRIBUTES = [ |
| [ ATT_select, jsEvalToFunction ], |
| [ ATT_display, jsEvalToFunction ], |
| [ ATT_values, jsEvalToValues ], |
| [ ATT_vars, jsEvalToValues ], |
| [ ATT_eval, jsEvalToExpressions ], |
| [ ATT_transclude, jsEvalToSelf ], |
| [ ATT_content, jsEvalToFunction ], |
| [ ATT_skip, jsEvalToFunction ] |
| ]; |
| |
| |
| /** |
| * Prepares a single node: preprocesses all template attributes of the |
| * node, and if there are any, assigns a jsid attribute and stores the |
| * preprocessed attributes under the jsid in the jstcache. |
| * |
| * @param {Element} node |
| * |
| * @return {Object} The jstcache entry. The processed jst attributes |
| * are properties of this object. If the node has no jst attributes, |
| * returns an object with no properties (the jscache_[0] entry). |
| */ |
| JstProcessor.prepareNode_ = function(node) { |
| // If the node already has a cache property, return it. |
| if (node[PROP_jstcache]) { |
| return node[PROP_jstcache]; |
| } |
| |
| // If it is not found, we always set the PROP_jstcache property on the node. |
| // Accessing the property is faster than executing getAttribute(). If we |
| // don't find the property on a node that was cloned in jstSelect_(), we |
| // will fall back to check for the attribute and set the property |
| // from cache. |
| |
| // If the node has an attribute indexing a cache object, set it as a property |
| // and return it. |
| var jstid = domGetAttribute(node, ATT_jstcache); |
| if (jstid != null) { |
| return node[PROP_jstcache] = JstProcessor.jstcache_[jstid]; |
| } |
| |
| var attributeValues = JstProcessor.attributeValues_; |
| var attributeList = JstProcessor.attributeList_; |
| attributeList.length = 0; |
| |
| // Look for interesting attributes. |
| for (var i = 0, I = jsLength(JST_ATTRIBUTES); i < I; ++i) { |
| var name = JST_ATTRIBUTES[i][0]; |
| var value = domGetAttribute(node, name); |
| attributeValues[name] = value; |
| if (value != null) { |
| attributeList.push(name + "=" + value); |
| } |
| } |
| |
| // If none found, mark this node to prevent further inspection, and return |
| // an empty cache object. |
| if (attributeList.length == 0) { |
| domSetAttribute(node, ATT_jstcache, STRING_zero); |
| return node[PROP_jstcache] = JstProcessor.jstcache_[0]; |
| } |
| |
| // If we already have a cache object corresponding to these attributes, |
| // annotate the node with it, and return it. |
| var attstring = attributeList.join(CHAR_ampersand); |
| if (jstid = JstProcessor.jstcacheattributes_[attstring]) { |
| domSetAttribute(node, ATT_jstcache, jstid); |
| return node[PROP_jstcache] = JstProcessor.jstcache_[jstid]; |
| } |
| |
| // Otherwise, build a new cache object. |
| var jstcache = {}; |
| for (var i = 0, I = jsLength(JST_ATTRIBUTES); i < I; ++i) { |
| var att = JST_ATTRIBUTES[i]; |
| var name = att[0]; |
| var parse = att[1]; |
| var value = attributeValues[name]; |
| if (value != null) { |
| jstcache[name] = parse(value); |
| } |
| } |
| |
| jstid = STRING_empty + ++JstProcessor.jstid_; |
| domSetAttribute(node, ATT_jstcache, jstid); |
| JstProcessor.jstcache_[jstid] = jstcache; |
| JstProcessor.jstcacheattributes_[attstring] = jstid; |
| |
| return node[PROP_jstcache] = jstcache; |
| }; |
| |
| |
| /** |
| * Runs the given function in our state machine. |
| * |
| * It's informative to view the set of all function calls as a tree: |
| * - nodes are states |
| * - edges are state transitions, implemented as calls to the pending |
| * functions in the stack. |
| * - pre-order function calls are downward edges (recursion into call). |
| * - post-order function calls are upward edges (return from call). |
| * - leaves are nodes which do not recurse. |
| * We represent the call tree as an array of array of calls, indexed as |
| * stack[depth][index]. Here [depth] indexes into the call stack, and |
| * [index] indexes into the call queue at that depth. We require a call |
| * queue so that a node may branch to more than one child |
| * (which will be called serially), typically due to a loop structure. |
| * |
| * @param {Function} f The first function to run. |
| */ |
| JstProcessor.prototype.run_ = function(f) { |
| var me = this; |
| |
| /** |
| * A stack of queues of pre-order calls. |
| * The inner arrays (constituent queues) are structured as |
| * [ arg2, arg1, method, arg2, arg1, method, ...] |
| * ie. a flattened array of methods with 2 arguments, in reverse order |
| * for efficient push/pop. |
| * |
| * The outer array is a stack of such queues. |
| * |
| * @type Array.<Array> |
| */ |
| var calls = me.calls_ = []; |
| |
| /** |
| * The index into the queue for each depth. NOTE: Alternative would |
| * be to maintain the queues in reverse order (popping off of the |
| * end) but the repeated calls to .pop() consumed 90% of this |
| * function's execution time. |
| * @type Array.<number> |
| */ |
| var queueIndices = me.queueIndices_ = []; |
| |
| /** |
| * A pool of empty arrays. Minimizes object allocation for IE6's benefit. |
| * @type Array.<Array> |
| */ |
| var arrayPool = me.arrayPool_ = []; |
| |
| f(); |
| var queue, queueIndex; |
| var method, arg1, arg2; |
| var temp; |
| while (calls.length) { |
| queue = calls[calls.length - 1]; |
| queueIndex = queueIndices[queueIndices.length - 1]; |
| if (queueIndex >= queue.length) { |
| me.recycleArray_(calls.pop()); |
| queueIndices.pop(); |
| continue; |
| } |
| |
| // Run the first function in the queue. |
| method = queue[queueIndex++]; |
| arg1 = queue[queueIndex++]; |
| arg2 = queue[queueIndex++]; |
| queueIndices[queueIndices.length - 1] = queueIndex; |
| method.call(me, arg1, arg2); |
| } |
| }; |
| |
| |
| /** |
| * Pushes one or more functions onto the stack. These will be run in sequence, |
| * interspersed with any recursive calls that they make. |
| * |
| * This method takes ownership of the given array! |
| * |
| * @param {Array} args Array of method calls structured as |
| * [ method, arg1, arg2, method, arg1, arg2, ... ] |
| */ |
| JstProcessor.prototype.push_ = function(args) { |
| this.calls_.push(args); |
| this.queueIndices_.push(0); |
| }; |
| |
| |
| /** |
| * Enable/disable debugging. |
| * @param {boolean} debugging New state |
| */ |
| JstProcessor.prototype.setDebugging = function(debugging) { |
| }; |
| |
| |
| JstProcessor.prototype.createArray_ = function() { |
| if (this.arrayPool_.length) { |
| return this.arrayPool_.pop(); |
| } else { |
| return []; |
| } |
| }; |
| |
| |
| JstProcessor.prototype.recycleArray_ = function(array) { |
| arrayClear(array); |
| this.arrayPool_.push(array); |
| }; |
| |
| /** |
| * Implements internals of jstProcess. This processes the two |
| * attributes transclude and jsselect, which replace or multiply |
| * elements, hence the name "outer". The remainder of the attributes |
| * is processed in jstProcessInner_(), below. That function |
| * jsProcessInner_() only processes attributes that affect an existing |
| * node, but doesn't create or destroy nodes, hence the name |
| * "inner". jstProcessInner_() is called through jstSelect_() if there |
| * is a jsselect attribute (possibly for newly created clones of the |
| * current template node), or directly from here if there is none. |
| * |
| * @param {JsEvalContext} context |
| * |
| * @param {Element} template |
| */ |
| JstProcessor.prototype.jstProcessOuter_ = function(context, template) { |
| var me = this; |
| |
| var jstAttributes = me.jstAttributes_(template); |
| |
| var transclude = jstAttributes[ATT_transclude]; |
| if (transclude) { |
| var tr = jstGetTemplate(transclude); |
| if (tr) { |
| domReplaceChild(tr, template); |
| var call = me.createArray_(); |
| call.push(me.jstProcessOuter_, context, tr); |
| me.push_(call); |
| } else { |
| domRemoveNode(template); |
| } |
| return; |
| } |
| |
| var select = jstAttributes[ATT_select]; |
| if (select) { |
| me.jstSelect_(context, template, select); |
| } else { |
| me.jstProcessInner_(context, template); |
| } |
| }; |
| |
| |
| /** |
| * Implements internals of jstProcess. This processes all attributes |
| * except transclude and jsselect. It is called either from |
| * jstSelect_() for nodes that have a jsselect attribute so that the |
| * jsselect attribute will not be processed again, or else directly |
| * from jstProcessOuter_(). See the comment on jstProcessOuter_() for |
| * an explanation of the name. |
| * |
| * @param {JsEvalContext} context |
| * |
| * @param {Element} template |
| */ |
| JstProcessor.prototype.jstProcessInner_ = function(context, template) { |
| var me = this; |
| |
| var jstAttributes = me.jstAttributes_(template); |
| |
| // NOTE(mesch): See NOTE on ATT_content why this is a separate |
| // attribute, and not a special value in ATT_values. |
| var display = jstAttributes[ATT_display]; |
| if (display) { |
| var shouldDisplay = context.jsexec(display, template); |
| if (!shouldDisplay) { |
| displayNone(template); |
| return; |
| } |
| displayDefault(template); |
| } |
| |
| // NOTE(mesch): jsvars is evaluated before jsvalues, because it's |
| // more useful to be able to use var values in attribute value |
| // expressions than vice versa. |
| var values = jstAttributes[ATT_vars]; |
| if (values) { |
| me.jstVars_(context, template, values); |
| } |
| |
| values = jstAttributes[ATT_values]; |
| if (values) { |
| me.jstValues_(context, template, values); |
| } |
| |
| // Evaluate expressions immediately. Useful for hooking callbacks |
| // into jstemplates. |
| // |
| // NOTE(mesch): Evaluation order is sometimes significant, e.g. when |
| // the expression evaluated in jseval relies on the values set in |
| // jsvalues, so it needs to be evaluated *after* |
| // jsvalues. TODO(mesch): This is quite arbitrary, it would be |
| // better if this would have more necessity to it. |
| var expressions = jstAttributes[ATT_eval]; |
| if (expressions) { |
| for (var i = 0, I = jsLength(expressions); i < I; ++i) { |
| context.jsexec(expressions[i], template); |
| } |
| } |
| |
| var skip = jstAttributes[ATT_skip]; |
| if (skip) { |
| var shouldSkip = context.jsexec(skip, template); |
| if (shouldSkip) return; |
| } |
| |
| // NOTE(mesch): content is a separate attribute, instead of just a |
| // special value mentioned in values, for two reasons: (1) it is |
| // fairly common to have only mapped content, and writing |
| // content="expr" is shorter than writing values="content:expr", and |
| // (2) the presence of content actually terminates traversal, and we |
| // need to check for that. Display is a separate attribute for a |
| // reason similar to the second, in that its presence *may* |
| // terminate traversal. |
| var content = jstAttributes[ATT_content]; |
| if (content) { |
| me.jstContent_(context, template, content); |
| |
| } else { |
| // Newly generated children should be ignored, so we explicitly |
| // store the children to be processed. |
| var queue = me.createArray_(); |
| for (var c = template.firstChild; c; c = c.nextSibling) { |
| if (c.nodeType == DOM_ELEMENT_NODE) { |
| queue.push(me.jstProcessOuter_, context, c); |
| } |
| } |
| if (queue.length) me.push_(queue); |
| } |
| }; |
| |
| |
| /** |
| * Implements the jsselect attribute: evalutes the value of the |
| * jsselect attribute in the current context, with the current |
| * variable bindings (see JsEvalContext.jseval()). If the value is an |
| * array, the current template node is multiplied once for every |
| * element in the array, with the array element being the context |
| * object. If the array is empty, or the value is undefined, then the |
| * current template node is dropped. If the value is not an array, |
| * then it is just made the context object. |
| * |
| * @param {JsEvalContext} context The current evaluation context. |
| * |
| * @param {Element} template The currently processed node of the template. |
| * |
| * @param {Function} select The javascript expression to evaluate. |
| * |
| * @notypecheck FIXME(hmitchell): See OCL6434950. instance and value need |
| * type checks. |
| */ |
| JstProcessor.prototype.jstSelect_ = function(context, template, select) { |
| var me = this; |
| |
| var value = context.jsexec(select, template); |
| |
| // Enable reprocessing: if this template is reprocessed, then only |
| // fill the section instance here. Otherwise do the cardinal |
| // processing of a new template. |
| var instance = domGetAttribute(template, ATT_instance); |
| |
| var instanceLast = false; |
| if (instance) { |
| if (instance.charAt(0) == CHAR_asterisk) { |
| instance = parseInt10(instance.substr(1)); |
| instanceLast = true; |
| } else { |
| instance = parseInt10(/** @type string */(instance)); |
| } |
| } |
| |
| // The expression value instanceof Array is occasionally false for |
| // arrays, seen in Firefox. Thus we recognize an array as an object |
| // which is not null that has a length property. Notice that this |
| // also matches input data with a length property, so this property |
| // name should be avoided in input data. |
| var multiple = isArray(value); |
| var count = multiple ? jsLength(value) : 1; |
| var multipleEmpty = (multiple && count == 0); |
| |
| if (multiple) { |
| if (multipleEmpty) { |
| // For an empty array, keep the first template instance and mark |
| // it last. Remove all other template instances. |
| if (!instance) { |
| domSetAttribute(template, ATT_instance, STRING_asteriskzero); |
| displayNone(template); |
| } else { |
| domRemoveNode(template); |
| } |
| |
| } else { |
| displayDefault(template); |
| // For a non empty array, create as many template instances as |
| // are needed. If the template is first processed, as many |
| // template instances are needed as there are values in the |
| // array. If the template is reprocessed, new template instances |
| // are only needed if there are more array values than template |
| // instances. Those additional instances are created by |
| // replicating the last template instance. |
| // |
| // When the template is first processed, there is no jsinstance |
| // attribute. This is indicated by instance === null, except in |
| // opera it is instance === "". Notice also that the === is |
| // essential, because 0 == "", presumably via type coercion to |
| // boolean. |
| if (instance === null || instance === STRING_empty || |
| (instanceLast && instance < count - 1)) { |
| // A queue of calls to push. |
| var queue = me.createArray_(); |
| |
| var instancesStart = instance || 0; |
| var i, I, clone; |
| for (i = instancesStart, I = count - 1; i < I; ++i) { |
| var node = domCloneNode(template); |
| domInsertBefore(node, template); |
| |
| jstSetInstance(/** @type Element */(node), value, i); |
| clone = context.clone(value[i], i, count); |
| |
| queue.push(me.jstProcessInner_, clone, node, |
| JsEvalContext.recycle, clone, null); |
| |
| } |
| // Push the originally present template instance last to keep |
| // the order aligned with the DOM order, because the newly |
| // created template instances are inserted *before* the |
| // original instance. |
| jstSetInstance(template, value, i); |
| clone = context.clone(value[i], i, count); |
| queue.push(me.jstProcessInner_, clone, template, |
| JsEvalContext.recycle, clone, null); |
| me.push_(queue); |
| } else if (instance < count) { |
| var v = value[instance]; |
| |
| jstSetInstance(template, value, instance); |
| var clone = context.clone(v, instance, count); |
| var queue = me.createArray_(); |
| queue.push(me.jstProcessInner_, clone, template, |
| JsEvalContext.recycle, clone, null); |
| me.push_(queue); |
| } else { |
| domRemoveNode(template); |
| } |
| } |
| } else { |
| if (value == null) { |
| displayNone(template); |
| } else { |
| displayDefault(template); |
| var clone = context.clone(value, 0, 1); |
| var queue = me.createArray_(); |
| queue.push(me.jstProcessInner_, clone, template, |
| JsEvalContext.recycle, clone, null); |
| me.push_(queue); |
| } |
| } |
| }; |
| |
| |
| /** |
| * Implements the jsvars attribute: evaluates each of the values and |
| * assigns them to variables in the current context. Similar to |
| * jsvalues, except that all values are treated as vars, independent |
| * of their names. |
| * |
| * @param {JsEvalContext} context Current evaluation context. |
| * |
| * @param {Element} template Currently processed template node. |
| * |
| * @param {Array} values Processed value of the jsvalues attribute: a |
| * flattened array of pairs. The second element in the pair is a |
| * function that can be passed to jsexec() for evaluation in the |
| * current jscontext, and the first element is the variable name that |
| * the value returned by jsexec is assigned to. |
| */ |
| JstProcessor.prototype.jstVars_ = function(context, template, values) { |
| for (var i = 0, I = jsLength(values); i < I; i += 2) { |
| var label = values[i]; |
| var value = context.jsexec(values[i+1], template); |
| context.setVariable(label, value); |
| } |
| }; |
| |
| |
| /** |
| * Implements the jsvalues attribute: evaluates each of the values and |
| * assigns them to variables in the current context (if the name |
| * starts with '$', javascript properties of the current template node |
| * (if the name starts with '.'), or DOM attributes of the current |
| * template node (otherwise). Since DOM attribute values are always |
| * strings, the value is coerced to string in the latter case, |
| * otherwise it's the uncoerced javascript value. |
| * |
| * @param {JsEvalContext} context Current evaluation context. |
| * |
| * @param {Element} template Currently processed template node. |
| * |
| * @param {Array} values Processed value of the jsvalues attribute: a |
| * flattened array of pairs. The second element in the pair is a |
| * function that can be passed to jsexec() for evaluation in the |
| * current jscontext, and the first element is the label that |
| * determines where the value returned by jsexec is assigned to. |
| */ |
| JstProcessor.prototype.jstValues_ = function(context, template, values) { |
| for (var i = 0, I = jsLength(values); i < I; i += 2) { |
| var label = values[i]; |
| var value = context.jsexec(values[i+1], template); |
| |
| if (label.charAt(0) == CHAR_dollar) { |
| // A jsvalues entry whose name starts with $ sets a local |
| // variable. |
| context.setVariable(label, value); |
| |
| } else if (label.charAt(0) == CHAR_period) { |
| // A jsvalues entry whose name starts with . sets a property of |
| // the current template node. The name may have further dot |
| // separated components, which are translated into namespace |
| // objects. This specifically allows to set properties on .style |
| // using jsvalues. NOTE(mesch): Setting the style attribute has |
| // no effect in IE and hence should not be done anyway. |
| var nameSpaceLabel = label.substr(1).split(CHAR_period); |
| var nameSpaceObject = template; |
| var nameSpaceDepth = jsLength(nameSpaceLabel); |
| for (var j = 0, J = nameSpaceDepth - 1; j < J; ++j) { |
| var jLabel = nameSpaceLabel[j]; |
| if (!nameSpaceObject[jLabel]) { |
| nameSpaceObject[jLabel] = {}; |
| } |
| nameSpaceObject = nameSpaceObject[jLabel]; |
| } |
| nameSpaceObject[nameSpaceLabel[nameSpaceDepth - 1]] = value; |
| |
| } else if (label) { |
| // Any other jsvalues entry sets an attribute of the current |
| // template node. |
| if (typeof value == TYPE_boolean) { |
| // Handle boolean values that are set as attributes specially, |
| // according to the XML/HTML convention. |
| if (value) { |
| domSetAttribute(template, label, label); |
| } else { |
| domRemoveAttribute(template, label); |
| } |
| } else { |
| domSetAttribute(template, label, STRING_empty + value); |
| } |
| } |
| } |
| }; |
| |
| |
| /** |
| * Implements the jscontent attribute. Evalutes the expression in |
| * jscontent in the current context and with the current variables, |
| * and assigns its string value to the content of the current template |
| * node. |
| * |
| * @param {JsEvalContext} context Current evaluation context. |
| * |
| * @param {Element} template Currently processed template node. |
| * |
| * @param {Function} content Processed value of the jscontent |
| * attribute. |
| */ |
| JstProcessor.prototype.jstContent_ = function(context, template, content) { |
| // NOTE(mesch): Profiling shows that this method costs significant |
| // time. In jstemplate_perf.html, it's about 50%. I tried to replace |
| // by HTML escaping and assignment to innerHTML, but that was even |
| // slower. |
| var value = STRING_empty + context.jsexec(content, template); |
| // Prevent flicker when refreshing a template and the value doesn't |
| // change. |
| if (template.innerHTML == value) { |
| return; |
| } |
| while (template.firstChild) { |
| domRemoveNode(template.firstChild); |
| } |
| var t = domCreateTextNode(this.document_, value); |
| domAppendChild(template, t); |
| }; |
| |
| |
| /** |
| * Caches access to and parsing of template processing attributes. If |
| * domGetAttribute() is called every time a template attribute value |
| * is used, it takes more than 10% of the time. |
| * |
| * @param {Element} template A DOM element node of the template. |
| * |
| * @return {Object} A javascript object that has all js template |
| * processing attribute values of the node as properties. |
| */ |
| JstProcessor.prototype.jstAttributes_ = function(template) { |
| if (template[PROP_jstcache]) { |
| return template[PROP_jstcache]; |
| } |
| |
| var jstid = domGetAttribute(template, ATT_jstcache); |
| if (jstid) { |
| return template[PROP_jstcache] = JstProcessor.jstcache_[jstid]; |
| } |
| |
| return JstProcessor.prepareNode_(template); |
| }; |
| |
| |
| /** |
| * Helps to implement the transclude attribute, and is the initial |
| * call to get hold of a template from its ID. |
| * |
| * If the ID is not present in the DOM, and opt_loadHtmlFn is specified, this |
| * function will call that function and add the result to the DOM, before |
| * returning the template. |
| * |
| * @param {string} name The ID of the HTML element used as template. |
| * @param {Function} opt_loadHtmlFn A function which, when called, will return |
| * HTML that contains an element whose ID is 'name'. |
| * |
| * @return {Element|null} The DOM node of the template. (Only element nodes |
| * can be found by ID, hence it's a Element.) |
| */ |
| function jstGetTemplate(name, opt_loadHtmlFn) { |
| var doc = document; |
| var section; |
| if (opt_loadHtmlFn) { |
| section = jstLoadTemplateIfNotPresent(doc, name, opt_loadHtmlFn); |
| } else { |
| section = domGetElementById(doc, name); |
| } |
| if (section) { |
| JstProcessor.prepareTemplate_(section); |
| var ret = domCloneElement(section); |
| domRemoveAttribute(ret, STRING_id); |
| return ret; |
| } else { |
| return null; |
| } |
| } |
| |
| /** |
| * This function is the same as 'jstGetTemplate' but, if the template |
| * does not exist, throw an exception. |
| * |
| * @param {string} name The ID of the HTML element used as template. |
| * @param {Function} opt_loadHtmlFn A function which, when called, will return |
| * HTML that contains an element whose ID is 'name'. |
| * |
| * @return {Element} The DOM node of the template. (Only element nodes |
| * can be found by ID, hence it's a Element.) |
| */ |
| function jstGetTemplateOrDie(name, opt_loadHtmlFn) { |
| var x = jstGetTemplate(name, opt_loadHtmlFn); |
| check(x !== null); |
| return /** @type Element */(x); |
| } |
| |
| |
| /** |
| * If an element with id 'name' is not present in the document, call loadHtmlFn |
| * and insert the result into the DOM. |
| * |
| * @param {Document} doc |
| * @param {string} name |
| * @param {Function} loadHtmlFn A function that returns HTML to be inserted |
| * into the DOM. |
| * @param {string} opt_target The id of a DOM object under which to attach the |
| * HTML once it's inserted. An object with this id is created if it does not |
| * exist. |
| * @return {Element} The node whose id is 'name' |
| */ |
| function jstLoadTemplateIfNotPresent(doc, name, loadHtmlFn, opt_target) { |
| var section = domGetElementById(doc, name); |
| if (section) { |
| return section; |
| } |
| // Load any necessary HTML and try again. |
| jstLoadTemplate_(doc, loadHtmlFn(), opt_target || STRING_jsts); |
| var section = domGetElementById(doc, name); |
| if (!section) { |
| log("Error: jstGetTemplate was provided with opt_loadHtmlFn, " + |
| "but that function did not provide the id '" + name + "'."); |
| } |
| return /** @type Element */(section); |
| } |
| |
| |
| /** |
| * Loads the given HTML text into the given document, so that |
| * jstGetTemplate can find it. |
| * |
| * We append it to the element identified by targetId, which is hidden. |
| * If it doesn't exist, it is created. |
| * |
| * @param {Document} doc The document to create the template in. |
| * |
| * @param {string} html HTML text to be inserted into the document. |
| * |
| * @param {string} targetId The id of a DOM object under which to attach the |
| * HTML once it's inserted. An object with this id is created if it does not |
| * exist. |
| */ |
| function jstLoadTemplate_(doc, html, targetId) { |
| var existing_target = domGetElementById(doc, targetId); |
| var target; |
| if (!existing_target) { |
| target = domCreateElement(doc, STRING_div); |
| target.id = targetId; |
| displayNone(target); |
| positionAbsolute(target); |
| domAppendChild(doc.body, target); |
| } else { |
| target = existing_target; |
| } |
| var div = domCreateElement(doc, STRING_div); |
| target.appendChild(div); |
| div.innerHTML = html; |
| } |
| |
| |
| /** |
| * Sets the jsinstance attribute on a node according to its context. |
| * |
| * @param {Element} template The template DOM node to set the instance |
| * attribute on. |
| * |
| * @param {Array} values The current input context, the array of |
| * values of which the template node will render one instance. |
| * |
| * @param {number} index The index of this template node in values. |
| */ |
| function jstSetInstance(template, values, index) { |
| if (index == jsLength(values) - 1) { |
| domSetAttribute(template, ATT_instance, CHAR_asterisk + index); |
| } else { |
| domSetAttribute(template, ATT_instance, STRING_empty + index); |
| } |
| } |
| |
| |
| /** |
| * Log the current state. |
| * @param {string} caller An identifier for the caller of .log_. |
| * @param {Element} template The template node being processed. |
| * @param {Object} jstAttributeValues The jst attributes of the template node. |
| */ |
| JstProcessor.prototype.logState_ = function( |
| caller, template, jstAttributeValues) { |
| }; |
| |
| |
| /** |
| * Retrieve the processing logs. |
| * @return {Array.<string>} The processing logs. |
| */ |
| JstProcessor.prototype.getLogs = function() { |
| return this.logs_; |
| }; |