If you are developing an extension for one of the mozilla applications (e.g. Firefox, Thunderbird, etc.) you define a extension id in the install.rdf.
If for some reason you need to know the extension id e.g. to retrieve the extension dir in local file system (1) or if you want to send it to a webservice (useage statistic) etc. it would be nice to get it from the install.rdf in favour to have it hardcoded in your javascript code.
But how to access the extension id from within my extension?
1) example code:
var extId = "myspecialthunderbirdextid#mydomain.com";
var filename = "install.rdf";
var file = extManager.getInstallLocation(extId).getItemFile(extId, filename);
var fullPathToFile = file.path;
I'm fairly sure the 'hard-coded ID' should never change throughout the lifetime of an extension. That's the entire purpose of the ID: it's unique to that extension, permanently. Just store it as a constant and use that constant in your libraries. There's nothing wrong with that.
What IS bad practice is using the install.rdf, which exists for the sole purpose of... well, installing. Once the extension is developed, the install.rdf file's state is irrelevant and could well be inconsistent.
"An Install Manifest is the file an Add-on Manager-enabled XUL application uses to determine information about an add-on as it is being installed" [1]
To give it an analogy, it's like accessing the memory of a deleted object from an overflow. That object still exists in memory but it's not logically longer relevant and using its data is a really, really bad idea.
[1] https://developer.mozilla.org/en/install_manifests
Like lwburk, I don't think its available through Mozilla's API's, but I have an idea which works, but it seems like a complex hack. The basic steps are:
Set up a custom resource url to point to your extension's base directory
Read the file and parse it into XML
Pull the id out using XPath
Add the following line to your chrome.manifest file
resource packagename-base-dir chrome/../
Then we can grab and parse the file with the following code:
function myId(){
var req = new XMLHttpRequest();
// synchronous request
req.open('GET', "resource://packagename-base-dir/install.rdf", false);
req.send(null);
if( req.status !== 0){
throw("file not found");
}
var data = req.responseText;
// this is so that we can query xpath with namespaces
var nsResolver = function(prefix){
var ns = {
"rdf" : "http://www.w3.org/1999/02/22-rdf-syntax-ns#",
"em" : "http://www.mozilla.org/2004/em-rdf#"
};
return ns[prefix] || null;
};
var parser = CCIN("#mozilla.org/xmlextras/domparser;1", Ci.nsIDOMParser);
var doc = parser.parseFromString(data, "text/xml");
// you might have to change this xpath expression a bit to fit your setup
var myExtId = doc.evaluate("//em:targetApplication//em:id", doc, nsResolver,
Ci.nsIDOMXPathResult.FIRST_ORDERED_NODE_TYPE, null);
return myExtId.singleNodeValue.textContent;
}
I chose to use a XMLHttpRequest(as opposed to simply reading from a file) to retrieve the contents since in Firefox 4, extensions aren't necessarily unzipped. However, XMLHttpRequest will still work if the extension remains packed (haven't tested this, but have read about it).
Please note that resource URL's are shared by all installed extensions, so if packagename-base-dir isn't unique, you'll run into problems. You might be able to leverage Programmatically adding aliases to solve this problem.
This question prompted me to join StackOverflow tonight, and I'm looking forward participating more... I'll be seeing you guys around!
As Firefox now just uses Chrome's WebExtension API, you can use #serg's answer at How to get my extension's id from JavaScript?:
You can get it like this (no extra permissions required) in two
different ways:
Using runtime api: var myid = chrome.runtime.id;
Using i18n api: var myid = chrome.i18n.getMessage("##extension_id");
I can't prove a negative, but I've done some research and I don't think this is possible. Evidence:
This question, which shows that
the nsIExtensionManager interface
expects you to retrieve extension
information by ID
The full nsIExtensionManager interface
description, which shows no
method that helps
The interface does allow you to retrieve a full list of installed extensions, so it's possible to retrieve information about your extension using something other than the ID. See this code, for example:
var em = Cc['#mozilla.org/extensions/manager;1']
.getService(Ci.nsIExtensionManager);
const nsIUpdateItem = Ci.nsIUpdateItem;
var extension_type = nsIUpdateItem.TYPE_EXTENSION;
items = em.getItemList(extension_type, {});
items.forEach(function(item, index, array) {
alert(item.name + " / " + item.id + " version: " + item.version);
});
But you'd still be relying on hardcoded properties, of which the ID is the only one guaranteed to be unique.
Take a look on this add-on, maybe its author could help you, or yourself can figure out:
[Extension Manager] Extended is very
simple to use. After installing, just
open the extension manager by going to
Tools and the clicking Extensions. You
will now see next to each extension
the id of that extension.
(Not compatible yet with Firefox 4.0)
https://addons.mozilla.org/firefox/addon/2195
Related
Within our web application we load a lot of content from package files (zipped packages containing html, js, css, images and so on.) The module loader (client side JS) processes the packages and makes the content available to the DOM using blob urls.
While this works very nice, it's sometimes tedious to find the right piece of JavaScript file for debugging.
IE: in chrome in the development console->sources all blob urls are listed under (no domain) and have random names such as:
blob:https://example.com/0613efd7-6977-4872-981f-519eea0bc911
In a normal production environment there are roughly 100 lines like this, so finding the right one might take some time.
I'd pretty much like to name the blob urls, or do something to make them easier to find for debugging purposes. This seems possible since WebPack is doing something like this, however i can't seem to find how. Is there anybody that can hint me in the right direction.
Ok, the way I would do it is have some global that keeps a track of the URL's, using a simple reverse map.
One problem of course with this is that references to a blob that no longer exists will be kept in memory, but if say you was only enabling this for debugging purposes this might not be a problem.
var namedblobs = {};
function addNamedBlob(name, uri) {
namedblobs[uri] = name;
}
function getNamedBlob(uri) {
return namedblobs[uri];
}
function createSomeBlob() {
//for testing just a random number would do
return Math.random().toString();
}
var blob = createSomeBlob();
addNamedBlob("test1", blob);
addNamedBlob("test2", createSomeBlob());
console.log(getNamedBlob(blob)); //should be test1
Finally i have found a solution that works to my liking. For our application we already used a serviceworker which has caching active. So i ended up writing the module files into the serviceworker cache whenever somebody has debug mode turned on.
Since the url portion of the resource files is static this way, all the nice browser features such as breakpoints are now useable again.
Below i've posted the relevant code of the serviceworker. The rest of the code is just plain serviceworker caching.
api.serveScript = function(module, script, content){
try{
content = atob(content);
} catch(err){}
return new Promise(function(resolve, reject){
var init = {
status: 200,
statusText: "OK",
headers: {'Content-Type': 'text/javascript'}
};
caches.open("modulecache-1").then(function(cache) {
console.log('[ServiceWorker] Caching ' + module + "/" + script);
cache.put("/R/" + module + "/script/" + script, new Response(content, init));
resolve("/R/" + module + "/script/" + script);
});
});
}
Thanks for your answers and help. I hope this solution is going to help some others too.
#Keith's option is probably the best one. (create a Map of your blobURIs and easy to read file names).
You could also do a dynamic router that will point some nice url to the blobURIs, but if you are open to do this, then just don't use blobURIs.
An other hackish workaround, really less cleaner than the Map, would be to append a fragment identifier to your blobURI blob:https://example.com/0613efd7-6977-4872-981f-519eea0bc911#script_name.js.
Beware, This should work for application/javascript Blobs or some other resource types, but not for documents (html/svg/...) where this fragment identifier has a special meaning.
var hello = new Blob(["alert('hello')"], {type:'application/javascript'});
var script = document.createElement('script');
script.src = URL.createObjectURL(hello) + '#hello.js';
document.head.appendChild(script);
console.log(script.src);
var css = new Blob(["body{background:red}"], {type:'text/css'});
var style = document.createElement('link');
style.href = URL.createObjectURL(css) + '#style.css';
style.rel = 'stylesheet';
document.head.appendChild(style);
console.log(style.href);
And as a fiddle for browsers which doesn't like null origined StackSnippet's iframes.
I have a problem.
I have a list of SKU numbers (hundreds) that I'm trying to match with the title of the product that it belongs to. I have thought of a few ways to accomplish this, but I feel like I'm missing something... I'm hoping someone here has a quick and efficient idea to help me get this done.
The products come from Aidan Gray.
Attempt #1 (Batch Program Method) - FAIL:
After searching for a SKU in Aidan Gray, the website returns a URL that looks like below:
http://www.aidangrayhome.com/catalogsearch/result/?q=SKUNUMBER
... with "SKUNUMBER" obviously being a SKU.
The first result of the webpage is almost always the product.
To click the first result (through the address bar) the following can be entered (if Javascript is enabled through the address bar):
javascript:{document.getElementsByClassName("product-image")[0].click;}
I wanted to create a .bat file through Command Prompt and execute the following command:
firefox http://www.aidangrayhome.com/catalogsearch/result/?q=SKUNUMBER javascript:{document.getElementsByClassName("product-image")[0].click;}
... but Firefox doesn't seem to allow these two commands to execute in the same tab.
If that worked, I was going to go to http://tools.buzzstream.com/meta-tag-extractor, paste the resulting links to get the titles of the pages, and export the data to CSV format, and copy over the data I wanted.
Unfortunately, I am unable to open both the webpage and the Javascript in the same tab through a batch program.
Attempt #2 (I'm Feeling Lucky Method):
I was going to use Google's &btnI URL suffix to automatically redirect to the first result.
http://www.google.com/search?btnI&q=site:aidangrayhome.com+SKUNUMBER
After opening all the links in tabs, I was going to use a Firefox add-on called "Send Tab URLs" to copy the names of the tabs (which contain the product names) to the clipboard.
The problem is that most of the results were simply not lucky enough...
If anybody has an idea or tip to get this accomplished, I'd be very grateful.
I recommend using JScript for this. It's easy to include as hybrid code in a batch script, its structure and syntax is familiar to anyone comfortable with JavaScript, and you can use it to fetch web pages via XMLHTTPRequest (a.k.a. Ajax by the less-informed) and build a DOM object from the .responseText using an htmlfile COM object.
Anyway, challenge: accepted. Save this with a .bat extension. It'll look for a text file containing SKUs, one per line, and fetch and scrape the search page for each, writing info from the first anchor element with a .className of "product-image" to a CSV file.
#if (#CodeSection == #Batch) #then
#echo off
setlocal
set "skufile=sku.txt"
set "outfile=output.csv"
set "URL=http://www.aidangrayhome.com/catalogsearch/result/?q="
rem // invoke JScript portion
cscript /nologo /e:jscript "%~f0" "%skufile%" "%outfile%" "%URL%"
echo Done.
rem // end main runtime
goto :EOF
#end // end batch / begin JScript chimera
var fso = WSH.CreateObject('scripting.filesystemobject'),
skufile = fso.OpenTextFile(WSH.Arguments(0), 1),
skus = skufile.ReadAll().split(/\r?\n/),
outfile = fso.CreateTextFile(WSH.Arguments(1), true),
URL = WSH.Arguments(2);
skufile.Close();
String.prototype.trim = function() { return this.replace(/^\s+|\s+$/g, ''); }
// returns a DOM root object
function fetch(url) {
var XHR = WSH.CreateObject("Microsoft.XMLHTTP"),
DOM = WSH.CreateObject('htmlfile');
WSH.StdErr.Write('fetching ' + url);
XHR.open("GET",url,true);
XHR.setRequestHeader('User-Agent','XMLHTTP/1.0');
XHR.send('');
while (XHR.readyState!=4) {WSH.Sleep(25)};
DOM.write(XHR.responseText);
return DOM;
}
function out(what) {
WSH.StdErr.Write(new Array(79).join(String.fromCharCode(8)));
WSH.Echo(what);
outfile.WriteLine(what);
}
WSH.Echo('Writing to ' + WSH.Arguments(1) + '...')
out('sku,product,URL');
for (var i=0; i<skus.length; i++) {
if (!skus[i]) continue;
var DOM = fetch(URL + skus[i]),
anchors = DOM.getElementsByTagName('a');
for (var j=0; j<anchors.length; j++) {
if (/\bproduct-image\b/i.test(anchors[j].className)) {
out(skus[i]+',"' + anchors[j].title.trim() + '","' + anchors[j].href + '"');
break;
}
}
}
outfile.Close();
Too bad the htmlfile COM object doesn't support getElementsByClassName. :/ But this seems to work well enough in my testing.
I'm trying to read in a local text file to perform functions like counting syllables, characters etc.,
I am trying to do this by doing:
var txtFile = new XMLHttpRequest();
txtFile.open("GET", "file://path/to/my/file.txt", true);
txtFile.onreadystatechange = function() {
if (txtFile.readyState === 4) { // Makes sure the document is ready to parse.
if (txtFile.status === 200) { // Makes sure it's found the file.
allText = txtFile.responseText;
//lines = txtFile.responseText.split("\r\n"); // Will separate each line into an array
} //"\r\n"
}
}
when I try to log 'txtFile' to the command line it prints [ObjectHtmlRequest], how do i look at what i'm loading and consequently iterate over it?
I also get an error message when i try doing this piece of code
var text = txtFile
//$(this).val();
//document.text_input.my_text.value = newtext;
var words = new Array(text.replace(/\s/g, ' ').split(' '));
which worked before, but i'm guessing it's not now because i'm no longer working with text
Most browsers won't allow JavaScript to use the local filesystem. Chrome definitely won't, I'm not sure about Firefox and the others.
What I do in that case is either :
Use a local web server based on the local directory if the file you want to read is static. I usually start it with python -mhttp.server (Python 3) or python -mSimpleHTTPServer (Python 2).
Use the latest HTML5 File API if you want to let the user choose the file. More information here.
EDIT: Well, what I said isn't entirely true. Chrome allows you to use local files, but you have to start it on the command line with a special switch (--allow-file-access-from-files), and frankly, it's a bother and is only really intended for development. Don't rely on it for anything in production!
I am trying to find a way where by we can auto save a file in Firefox using JS. The way I have done till yet using FireShot on a Windows Desktop:
var element = content.document.createElement("FireShotDataElement");
element.setAttribute("Entire", EntirePage);
element.setAttribute("Action", Action);
element.setAttribute("Key", Key);
element.setAttribute("BASE64Content", "");
element.setAttribute("Data", Data);
element.setAttribute("Document", content.document);
if (typeof(CapturedFrameId) != "undefined")
element.setAttribute("CapturedFrameId", CapturedFrameId);
content.document.documentElement.appendChild(element);
var evt = content.document.createEvent("Events");
evt.initEvent("capturePageEvt", true, false);
element.dispatchEvent(evt);
But the issue is that it opens a dialog box to confirm the local drive location details. Is there a way I can hard code the local drive storage location and auto save the file?
If you are creating a Firefox add-on then FileUtils and NetUtil.asyncCopy are your friends:
Components.utils.import("resource://gre/modules/FileUtils.jsm");
Components.utils.import("resource://gre/modules/NetUtil.jsm");
var TEST_DATA = "this is a test string";
var source = Components.classes["#mozilla.org/io/string-input-stream;1"].
createInstance(Components.interfaces.nsIStringInputStream);
source.setData(TEST_DATA, TEST_DATA.length);
var file = new FileUtils.File("c:\\foo\\bar.txt");
var sink = file.openSafeFileOutputStream(file, FileUtils.MODE_WRONLY |
FileUtils.MODE_CREATE);
NetUtil.asyncCopy(source, sink);
This will asynchronously write the string this is a test string into the file c:\foo\bar.txt. Note that NetUtil.asyncCopy closes both streams automatically, you don't need to do it. However, you might want to pass a function as third parameter to this method - it will be called when the write operation is finished.
See also: Code snippets, writing to a file
Every computer has a different file structure. But still, there is a way. You can save it to cookie / session, depends on how "permanent" your data wants to be.
Do not consider writing a physical file as it requires extra permission.
I have a script CustomAction (Yes, I know all about the opinions that say don't use script CustomActions. I have a different opinion.)
I'd like to run a command, and capture the output. I can do this using the WScript.Shell COM object, then invoking shell.Exec(). But, this flashes a visible console window for the executed command.
To avoid that, I understand I can use the shell.Run() call, and specify "hidden" for the window appearance. But .Run() doesn't give me access to the StdOut of the executed process, so that means I'd need to create a temporary file and redirect the exe output to the temp file, then later read that temp file in script.
Some questions:
is this gonna work?
How do I generate a name for the temporary file? In .NET I could use a static method in the System.IO namespace, but I am using script here. I need to insure that the use has RW access, and also that no anti-virus program is going to puke on this.
Better ideas? I am trying very hard to avoid C/C++.
I could avoid all this if there were a way to query websites in IIS7 from script, without resorting to the IIS6 Compatibility pack, without using .NET (Microsoft.Web.Administration.ServerManager), and without execing a process (appcmd list sites).
I already asked a separate question on that topic; any suggestions on that would also be appreciated.
Answering my own question...
yes, this is going to work.
Use the Scripting.FileSystemObject thing within Javascript. There's a GetTempName() method that produces a file name suitable for temporary use, and a GetSpecialFolder() method that gets the location of the temp folder. There's even a BuildPath() method to combine them.
so far I don't have any better ideas.
Here's the code I used:
function GetWebSites_IIS7_B()
{
var ParseOneLine = function(oneLine) {
...regex parsing of output...
};
LogMessage("GetWebSites_IIS7_B() ENTER");
var shell = new ActiveXObject("WScript.Shell");
var fso = new ActiveXObject("Scripting.FileSystemObject");
var tmpdir = fso.GetSpecialFolder(SpecialFolders.TemporaryFolder);
var tmpFileName = fso.BuildPath(tmpdir, fso.GetTempName());
var windir = fso.GetSpecialFolder(SpecialFolders.WindowsFolder);
var appcmd = fso.BuildPath(windir,"system32\\inetsrv\\appcmd.exe") + " list sites";
// use cmd.exe to redirect the output
var rc = shell.Run("%comspec% /c " + appcmd + "> " + tmpFileName, WindowStyle.Hidden, true);
// WindowStyle.Hidden == 0
var ts = fso.OpenTextFile(tmpFileName, OpenMode.ForReading);
var sites = [];
// Read from the file and parse the results.
while (!ts.AtEndOfStream) {
var oneLine = ts.ReadLine();
var line = ParseOneLine(oneLine);
LogMessage(" site: " + line.name);
sites.push(line);
}
ts.Close();
fso.DeleteFile(tmpFileName);
return sites;
}