diff options
Diffstat (limited to 'chrome/common/extensions/docs/examples/extensions/benchmark/jst/jstemplate.js')
| -rw-r--r-- | chrome/common/extensions/docs/examples/extensions/benchmark/jst/jstemplate.js | 1018 |
1 files changed, 1018 insertions, 0 deletions
diff --git a/chrome/common/extensions/docs/examples/extensions/benchmark/jst/jstemplate.js b/chrome/common/extensions/docs/examples/extensions/benchmark/jst/jstemplate.js new file mode 100644 index 0000000..d2cc386 --- /dev/null +++ b/chrome/common/extensions/docs/examples/extensions/benchmark/jst/jstemplate.js @@ -0,0 +1,1018 @@ +// 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;
+ if (MAPS_DEBUG && opt_debugging) {
+ processor.setDebugging(opt_debugging);
+ }
+ 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));
+ if (MAPS_DEBUG && opt_debugging) {
+ log('jstProcess:' + '\n' + processor.getLogs().join('\n'));
+ }
+}
+
+
+/**
+ * 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() {
+ if (MAPS_DEBUG) {
+ /**
+ * An array of logging messages. These are collected during processing
+ * and dumped to the console at the end.
+ * @type Array.<string>
+ */
+ this.logs_ = [];
+ }
+}
+
+
+/**
+ * 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);
+ if (MAPS_DEBUG) {
+ jstcache.jstAttributeValues = jstcache.jstAttributeValues || {};
+ jstcache.jstAttributeValues[name] = 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) {
+ if (MAPS_DEBUG) {
+ this.debugging_ = 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);
+ if (MAPS_DEBUG && me.debugging_) {
+ me.logState_('Outer', template, jstAttributes.jstAttributeValues);
+ }
+
+ 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);
+ if (MAPS_DEBUG && me.debugging_) {
+ me.logState_('Inner', template, jstAttributes.jstAttributeValues);
+ }
+
+ // 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 (MAPS_DEBUG && me.debugging_) {
+ me.logs_.push(ATT_display + ': ' + shouldDisplay + '<br/>');
+ }
+ 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 (MAPS_DEBUG && me.debugging_) {
+ me.logs_.push(ATT_skip + ': ' + shouldSkip + '<br/>');
+ }
+ 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) {
+ if (MAPS_DEBUG) {
+ var msg = '<table>';
+ msg += '<caption>' + caller + '</caption>';
+ msg += '<tbody>';
+ if (template.id) {
+ msg += '<tr><td>' + 'id:' + '</td><td>' + template.id + '</td></tr>';
+ }
+ if (template.name) {
+ msg += '<tr><td>' + 'name:' + '</td><td>' + template.name + '</td></tr>';
+ }
+ if (jstAttributeValues) {
+ msg += '<tr><td>' + 'attr:' +
+ '</td><td>' + jsToSource(jstAttributeValues) + '</td></tr>';
+ }
+ msg += '</tbody></table><br/>';
+ this.logs_.push(msg);
+ }
+};
+
+
+/**
+ * Retrieve the processing logs.
+ * @return {Array.<string>} The processing logs.
+ */
+JstProcessor.prototype.getLogs = function() {
+ return this.logs_;
+};
+
|