Dev : Tips : Disable XUL cache: Difference between revisions

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(redirect to devmo, all the up-to-date info is there minus the overlay reload thing, which sounds kinda iffy)
 
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==nglayout.debug.disable_xul_cache==
See [http://developer.mozilla.org/en/docs/Setting_up_extension_development_environment Setting up extension development environment] at [http://developer.mozilla.org MDC].


'''nglayout.debug.disable_xul_cache''' is a Mozilla [[Editing configuration|preference]] useful for extension developers. Basically when it is set to '''false''' (which is default), Mozilla caches chrome XUL and JavaScript (and more) in a file named XUL.mfl or similarly. Therefore, when making changes to your extension, you have to restart Mozilla in order to get new version used. As it is very inconvenient, many extension developers set this pref to '''true'''.
[[Category:Redirects]]
 
However even when '''nglayout.debug.disable_xul_cache''' is set to '''false''', Mozilla forbids rewriting *.jar files that contain installed extensions. To overcome this, and to avoid having to repack every change you make, you can unpack the JAR file you want to edit and make it permanent by updating chrome.rdf to point to the unpacked files instead of the JAR:
 
===Using chrome.rdf===
We assume that the extension is installed in profile in this section. For global installation see next section.
 
'''''Important!! Backup your profile before editing chrome.rdf!'''''
<ol><li>Unpack the JAR file you have, say <tt>Profiles\default\extensions\{YOUR-EXTENSION'S-GUID}\my-ext.jar</tt> to the same directory. You will get (at least) <tt>Profiles\default\extensions\{YOUR-EXTENSION'S-GUID}\content</tt> directory.</li>
<li>In <tt>Profiles\default\chrome\chrome.rdf</tt> look for ''my-ext.jar!'' and delete it. For example replace this line
<pre>c:baseURL="jar:file:///D:/Firefox/Profiles/default/extensions/{GUID}/chrome/my-ext.jar!/content/my-ext/"</pre>
with this:
<pre>c:baseURL="file:///D:/Firefox/Profiles/default/extensions/{GUID}/chrome/content/my-ext/"</pre>
Note, that you should also delete ''jar:'' at the beginning of the path.</li></ol>
 
===Changing install.rdf===
Perhaps you would like to package your extension as a series of directories, rather than
a jar file.  This would allow, for example, an XPI that could be easily edited and perhaps
checked back into a repository (e.g. a developer version).
 
Change the install.rdf from:
 
<tt><Description about="urn:mozilla:extension:file:myextension.jar"></tt>
 
to:
 
<tt><Description about="urn:mozilla:extension:file:myextension"></tt>
 
An [http://cgi29.plala.or.jp/mozzarel/addon/firefox0_9/non-jarred/  example]  
of this technique is available.  Also, myk is planning to update his [http://www.mozilla.org/docs/tutorials/tinderstatus/ tinderstatus extension]
to demonstrate this technique.
 
===Using installed-chrome.txt===
''Write me!''
{{msg:stub}}
 
==The overlay problem==
There is still another issue to be solved: a javascript that's called from the overlay.
The steps above help you test scripts that are not part of the overlay, like your settings dialog. But they can't help you test the overlay scripts because Firefox caches those.
 
The solution is to have the overlay script load its code from an external [[Dev : Extensions : Example Code : File IO|file]], which is reloaded and re-evaluated constantly.
Here's an example:
 
<pre>
var TheExt = {
 
//aFuncCall is a string to be evaluated as a function call
inject : function (aFuncCall) {
                var codeFileName =  "injected.js";
 
// Get profile directory
var file = Components.classes["@mozilla.org/file/directory_service;1"].
createInstance(Components.interfaces.nsIProperties).
get("ProfD", Components.interfaces.nsIFile);
 
// Get the file with the code
file.append(codeFileName);
if (!file.exists()) {
dump ("Error: " + file.path + "does not exist.\n");
reutrn;
}
 
// Read the file into code
var code = "";
var fstream = Components.classes["@mozilla.org/network/file-input-stream;1"]
.createInstance(Components.interfaces.nsIFileInputStream);
var sstream = Components.classes["@mozilla.org/scriptableinputstream;1"]
.createInstance(Components.interfaces.nsIScriptableInputStream);
fstream.init(file, 1, 0, false);
sstream.init(fstream);
code += sstream.read(-1);
sstream.close();
fstream.close();
// Run the code
eval(code);
eval(aFuncCall);
},
doAction : function() {
this.inject("doAction()");
}
}
 
dump ("Testing the extension.\n");
TheExt.doAction();
</pre>
 
The file injected.js simply looks like this:
<pre>
function doAction() {
dump ("Action!\n")
}
</pre>
 
You can add as many functions as you want. inject() evaluates all the functions in the file, but only executes the aFuncCall parameter.

Latest revision as of 19:53, 23 May 2007