Revision: 5354
Author: [email protected]
Date: Mon Apr 15 15:02:05 2013
Log: Refactoring Domado: bundle nodeClasses/inertCtor into an object.
https://codereview.appspot.com/8676043
Put nodeClasses and nodeTamers tables into an object to manage their
state transitions and consistency.
This is intended to make load order dependencies more visible and
fail-stop, make further refactoring easier, and prepare for future reuse
(e.g. taming setTimeout and XMLHttpRequest without an associated DOM).
[email protected]
http://code.google.com/p/google-caja/source/detail?r=5354
Modified:
/trunk/src/com/google/caja/plugin/domado.js
=======================================
--- /trunk/src/com/google/caja/plugin/domado.js Mon Apr 15 14:31:05 2013
+++ /trunk/src/com/google/caja/plugin/domado.js Mon Apr 15 15:02:05 2013
@@ -372,9 +372,6 @@
*
* The property's enumerability is inherited from the ancestor's
property's
* descriptor. The property is not writable or configurable.
- *
- * TODO(kpreid): Attempt to eliminate the need for uses of this. Some
may be
- * due to a fixed bug in ES5/3.
*/
function setOwn(object, propName, value) {
propName += '';
@@ -385,6 +382,17 @@
value: value
});
}
+
+ /**
+ * Shortcut for an unmodifiable property. Currently used only where
+ * overriding is not of interest, so doesn't do
definePropertyAllowOverride.
+ */
+ function setFinal(object, propName, value) {
+ Object.defineProperty(object, propName, {
+ enumerable: true,
+ value: value
+ });
+ }
/**
* Given that n is a string, is n an "array element" property name?
@@ -1143,6 +1151,98 @@
};
};
+ function TamingClassTable() {
+ var hop = Object.prototype.hasOwnProperty;
+
+ // would be Object.create(null) but not supported by ES5/3
+ var tamingCtors = {};
+ var safeCtors = {};
+
+ var prototypeNames = new WeakMap();
+
+ /**
+ * This does three things:
+ *
+ * Replace tamingCtor's prototype with one whose prototype is
someSuper.
+ *
+ * Hide the constructor of the products of tamingCtor, replacing it
with a
+ * function which just throws (but can still be used for instanceof
+ * checks).
+ *
+ * Register the inert ctor under the given name if not undefined.
+ */
+ this.inertCtor = function inertCtor(
+ tamingCtor, someSuper, opt_name, opt_writableProto) {
+ inherit(tamingCtor, someSuper, opt_writableProto);
+
+ var inert = function domadoInertConstructor() {
+ throw new TypeError('This constructor cannot be called directly.');
+ };
+ var string = opt_name ? '[domado inert constructor ' + opt_name + ']'
+ : '[domado inert constructor]';
+ inert.toString = cajaVM.constFunc(function inertCtorToString() {
+ return string;
+ });
+ inert.prototype = tamingCtor.prototype;
+ Object.freeze(inert); // not def, because inert.prototype must
remain
+ setOwn(tamingCtor.prototype, "constructor", inert);
+
+ if (opt_name !== undefined) {
+ setFinal(tamingCtors, opt_name, tamingCtor);
+ setFinal(safeCtors, opt_name, inert);
+ prototypeNames.set(inert.prototype, opt_name);
+ }
+
+ return inert;
+ };
+
+ this.registerSafeCtor = function registerSafeCtor(name, safeCtor) {
+ setFinal(tamingCtors, name, undefined); // prohibit inconsistency
+ setFinal(safeCtors, name, safeCtor);
+ // Registering multiple names is allowed. However, if we ever stop
having
+ // multiple names (HTMLElement vs. Element, HTMLDocument vs.
Document),
+ // which would be technically correct, this should become a failure
case.
+ if (!prototypeNames.has(safeCtor.prototype)) {
+ prototypeNames.set(safeCtor.prototype, name);
+ }
+ }
+
+ this.defAllAndFinish = function defAllAndFinish() {
+ for (var name in safeCtors) {
+ var ctor = safeCtors[name];
+ cajaVM.def(ctor);
+ }
+
+ // prohibit late additions
+ Object.freeze(tamingCtors);
+ Object.freeze(safeCtors);
+ };
+
+ this.exportTo = function exportTo(imports) {
+ if (Object.isExtensible(safeCtors)) {
+ throw new Error(
+ 'TamingClassTable: exportTo called before defAllAndFinish');
+ }
+ for (var name in safeCtors) {
+ var ctor = safeCtors[name];
+ Object.defineProperty(imports, name, {
+ enumerable: true,
+ configurable: true,
+ writable: true,
+ value: ctor
+ });
+ }
+ };
+
+ this.getTamingCtor = function(name) {
+ return hop.call(tamingCtors, name) ? tamingCtors[name] : undefined;
+ };
+
+ this.getNameOfPrototype = function(prototype) {
+ return prototypeNames.get(prototype);
+ };
+ }
+
cajaVM.def(domitaModules);
var NOT_EDITABLE = "Node not editable.";
@@ -1831,6 +1931,9 @@
// will recognize
bridal.initCanvasElements(containerNode);
+ var tamingClassTable = new TamingClassTable();
+ var inertCtor = tamingClassTable.inertCtor.bind(tamingClassTable);
+
// The private properties used in TameNodeConf are:
// feral (feral node)
// policy (access policy)
@@ -2637,8 +2740,10 @@
// <script> is specifically allowed because we make
provisions
// for controlling its content and src.
var domInterfaceName = schemaElem.domInterface;
- if (nodeTamers.hasOwnProperty(domInterfaceName)) {
- return new nodeTamers[domInterfaceName](node);
+ var specificTamer =
+ tamingClassTable.getTamingCtor(domInterfaceName);
+ if (specificTamer) {
+ return new specificTamer(node);
} else {
if (!nodeClassNoImplWarnings[domInterfaceName]) {
nodeClassNoImplWarnings[domInterfaceName] = true;
@@ -3344,46 +3449,6 @@
}
return null;
}
-
- // A map of tamed node classes, keyed by DOM Level 2 standard name,
which
- // will be exposed to the client (and are not usable as
constructors).
- var nodeClasses = {};
- // Ditto, but the taming constructors instead of the useless ones.
- var nodeTamers = {};
-
- /**
- * This does three things:
- *
- * Replace tamedCtor's prototype with one whose prototype is
someSuper.
- *
- * Hide the constructor of the products of tamedCtor, replacing it
with a
- * function which just throws (but can still be used for instanceof
- * checks).
- *
- * Register the inert ctor under the given name if specified.
- */
- function inertCtor(tamedCtor, someSuper, opt_name,
opt_writableProto) {
- inherit(tamedCtor, someSuper, opt_writableProto);
-
- var inert = function() {
- throw new TypeError('This constructor cannot be called
directly.');
- };
- var string = opt_name ? '[domado inert constructor ' + opt_name
+ ']'
- : '[domado inert constructor]';
- inert.toString = cajaVM.constFunc(function inertCtorToString() {
- return string;
- });
- inert.prototype = tamedCtor.prototype;
- Object.freeze(inert); // not def, because inert.prototype must
remain
- setOwn(tamedCtor.prototype, "constructor", inert);
-
- if (opt_name !== undefined) {
- nodeClasses[opt_name] = inert;
- nodeTamers[opt_name] = tamedCtor;
- }
-
- return inert;
- }
// We have now set up most of the 'support' facilities and are
starting to
// define node taming classes.
@@ -3436,19 +3501,15 @@
return Object.prototype.toString.call(self);
}
- var ctor = prototype.constructor;
- for (var name in nodeClasses) { // TODO(kpreid): less O(n)
- if (nodeClasses[name] === ctor) {
- if (ctor.prototype === self) {
- return "[domado PROTOTYPE OF " + name + "]";
- } else {
- return "[domado object " + name + ' ' + self.nodeName + "]";
- }
- }
+ var name = tamingClassTable.getNameOfPrototype(prototype);
+ if (!name) {
+ // try next ancestor
+ return nodeToStringSearch(self,
Object.getPrototypeOf(prototype));
+ } else if (prototype === self) {
+ return '[domado PROTOTYPE OF ' + name + ']';
+ } else {
+ return '[domado object ' + name + ' ' + self.nodeName + ']';
}
-
- // try next ancestor
- return nodeToStringSearch(self, Object.getPrototypeOf(prototype));
}
// abstract TameNode.prototype.nodeType
// abstract TameNode.prototype.nodeName
@@ -3917,8 +3978,9 @@
privates.geometryDelegate = node;
});
}
- nodeClasses.Element = inertCtor(TameElement, TameBackedNode,
- 'HTMLElement');
+ var defaultNodeClassCtor =
+ tamingClassTable.registerSafeCtor('Element',
+ inertCtor(TameElement, TameBackedNode, 'HTMLElement'));
registerElementScriptAttributeHandlers(TameElement.prototype);
TameElement.prototype.blur = nodeAmp(function(privates) {
privates.feral.blur();
@@ -5813,8 +5875,8 @@
installLocation(this);
}
- nodeClasses.Document =
- inertCtor(TameHTMLDocument, TameNode, 'HTMLDocument');
+ tamingClassTable.registerSafeCtor('Document',
+ inertCtor(TameHTMLDocument, TameNode, 'HTMLDocument'));
definePropertiesAwesomely(TameHTMLDocument.prototype, {
nodeType: P_constant(9),
nodeName: P_constant('#document'),
@@ -6398,19 +6460,19 @@
cajaVM.def(TameComputedStyle); // and its prototype
}
- // Note: nodeClasses.XMLHttpRequest is a ctor that *can* be directly
+ // Note: XMLHttpRequest is a ctor that *can* be directly
// called by cajoled code, so we do not use inertCtor().
- nodeClasses.XMLHttpRequest = domitaModules.TameXMLHttpRequest(
- taming,
- rulebreaker,
- domitaModules.XMLHttpRequestCtor(
- makeDOMAccessible,
- makeFunctionAccessible(window.XMLHttpRequest),
- makeFunctionAccessible(window.ActiveXObject),
- makeFunctionAccessible(window.XDomainRequest)),
- naiveUriPolicy,
- function () { return domicile.pseudoLocation.href; });
- cajaVM.def(nodeClasses.XMLHttpRequest);
+ tamingClassTable.registerSafeCtor('XMLHttpRequest',
+ cajaVM.def(domitaModules.TameXMLHttpRequest(
+ taming,
+ rulebreaker,
+ domitaModules.XMLHttpRequestCtor(
+ makeDOMAccessible,
+ makeFunctionAccessible(window.XMLHttpRequest),
+ makeFunctionAccessible(window.ActiveXObject),
+ makeFunctionAccessible(window.XDomainRequest)),
+ naiveUriPolicy,
+ function () { return domicile.pseudoLocation.href; })));
/**
* given a number, outputs the equivalent css text.
@@ -6787,12 +6849,7 @@
// Freeze exported classes. Must occur before TameHTMLDocument is
// instantiated.
- for (var name in nodeClasses) {
- var ctor = nodeClasses[name];
- cajaVM.def(ctor); // and its prototype
- }
- Object.freeze(nodeClasses);
- // fail hard if late-added item wouldn't be frozen
+ tamingClassTable.defAllAndFinish();
var tameDocument = new TameHTMLDocument(
document,
@@ -6826,15 +6883,7 @@
// Iterate over all node classes, assigning them to the Window object
// under their DOM Level 2 standard name. They have been frozen
above.
- for (var name in nodeClasses) {
- var ctor = nodeClasses[name];
- Object.defineProperty(tameWindow, name, {
- enumerable: true,
- configurable: true,
- writable: true,
- value: ctor
- });
- }
+ tamingClassTable.exportTo(tameWindow);
// TODO(ihab.awad): Build a more sophisticated virtual class
hierarchy by
// having a table of subclass relationships and implementing them.
@@ -6842,7 +6891,6 @@
// If a node class name in this list is not defined using
defineElement or
// inertCtor above, then it will now be bound to the HTMLElement
class.
var allDomNodeClasses = htmlSchema.getAllKnownScriptInterfaces();
- var defaultNodeClassCtor = nodeClasses.HTMLElement;
for (var i = 0; i < allDomNodeClasses.length; i++) {
var className = allDomNodeClasses[+i];
if (!(className in tameWindow)) {
--
---
You received this message because you are subscribed to the Google Groups "Google Caja Discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.
