Revision: 3780
Author: mikesamuel
Date: Tue Oct 6 20:14:04 2009
Log: Fixed spelling mistakes and added notes on validation.
http://code.google.com/p/google-caja/source/detail?r=3780
Modified:
/wiki/UserAgentContext.wiki
=======================================
--- /wiki/UserAgentContext.wiki Wed Sep 30 16:43:34 2009
+++ /wiki/UserAgentContext.wiki Tue Oct 6 20:14:04 2009
@@ -37,7 +37,7 @@
for which we cannot optimize code should dwindle for any given bug.
{{{ a[+i] = b[+i] }}}
can be significantly optimized on all browsers except certain older
-Firefox versions. And browers that implement EcmaScript 5 strict mode
+Firefox versions. And browsers that implement EcmaScript 5 strict mode
will require vastly fewer code transformations allowing smaller and
faster cajoled code to work on those browsers.
@@ -62,8 +62,8 @@
"(function () { 'use strict'; return this === null; })()": false
})
}}}
-where each key is a snippet of javascrit that has no side-effect, and
-where each value is the result produced by evaling that code in a
+where each key is a snippet of javascript that has no side-effect, and
+where each value is the result produced by {{{eval}}}ing that code in a
fresh execution context.
We can generate JSON files for each user-agent we care about and store
@@ -73,7 +73,7 @@
We assume two things about containers that load our
cajoled JS:
# That they never delete a member of the global object
- # That any additions to the global object will behave as specified. So
if a container provides its own implemention of window.JSON it is not
observably different from that on a user-agent with a native implementation.
+ # That any additions to the global object will behave as specified. So
if a container provides its own implementation of window.JSON it is not
observably different from that on a user-agent with a native implementation.
==Code Eliminating Minifier==
Next, we define a rewriter that reads the JSON file, and finds
@@ -118,3 +118,12 @@
probably have to write a function to strip out insignificant info (OS
version, locale, etc.) from the user agent string. It is always safe
to use an empty JSON object as an environment object.
+
+==Validating==
+We can check that the assumptions inherent in a user-agent JSON file hold
in a container, and in the presence of the cajita supporting code by doing
the following:
+
+ # Load the container and/or cajita supporting code
+ # Run "environment-checks.js" to generate a new JSON object
+ # Compare the JSON from (2) with that from the environment file.
+
+This validation can be done by containers to make sure they're not
violating the assumptions above, and could be done in the beginning of a
module to make sure that it only runs in the proper environment.
