I have built a Firefox extension using the Addon SDK that opens up a new tab with a HTML page from the extensions directory and attaches a content script to it:
function openHtmlLoadFormTab(htmlFileName, jsWorkerFileName) {
tabs.open({
url: data.url(htmlFileName),
onReady: function(tab) {
var tabWorker = tab.attach({
contentScriptFile: [ data.url(jsJquery), data.url(jsWorkerFileName) ]
});
}
});
}
I have an <input type="file"> in the HTML file and some code that handles the “submit” event in the JS file (these files are given by htmlFileName and jsWorkerFileName respectively)
Because of security reasons, I cannot access the full file path in JS with document.getElementById('uploadid').value. I only get the file’s name.
However, since this is a Firefox extension, I’m wondering if there is anyway to override this restriction?
I have been looking into netscape.security.PrivilegeManager.enablePrivilege("UniversalFileRead") and mozFullPath but I haven’t been able to get it to work. I believe it’s deprecated anyway?
The other solution is to build an XUL-based UI and prompt for the file there somehow, but I would like to know for sure if there is anyway to get this to work in HTML.
First edit with small example code
I built a small sample extension to illustrate how I’m doing things.
lib/main.js
var self = require('self');
var tabs = require('tabs');
var data = self.data;
var jsLoadForm = "load-form.js", htmlLoadForm = "load-form.html";
var jsJquery = 'jquery-1.8.0.min.js';
exports.onUnload = function(reason) {};
exports.main = function(options, callbacks) {
// TODO: remove this debugging line
openHtmlLoadFormTab(htmlLoadForm, jsLoadForm);
};
function openHtmlLoadFormTab(htmlFileName, jsWorkerFileName) {
tabs.open({
url: data.url(htmlFileName),
onReady: function(tab) {
var tabWorker = tab.attach({
contentScriptFile: [ data.url(jsJquery), data.url(jsWorkerFileName) ]
});
}
});
}
data/load-form.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>Form</title>
<script lang="text/javascript">
function fileChanged(e) {
// this is just the file name
alert("html js: files[0].name: " + e.files[0].name);
// mozFullPath is indeed empty, NOT undefined
alert("html js: files[0].mozFullPath: " + e.files[0].mozFullPath);
}
</script>
</head>
<body>
<form name="my-form" id="my-form" action="">
<div>
<label for="uploadid1" id="uploadlabel1">File (JS in HTML):</label>
<input type="file" name="uploadid1" id="uploadid1" onchange="fileChanged(this)"/>
</div>
<div>
<label for="uploadid2" id="uploadlabel2">File (JS in content script): </label>
<input type="file" name="uploadid2" id="uploadid2" onchange="fileChangedInContentScript(this)"/>
</div>
<div>
<label for="uploadid3" id="uploadlabel3">File (JS using jQuery in content script):</label>
<input type="file" name="uploadid3" id="uploadid3" />
</div>
</form>
</body>
</html>
data/load-form.js
$(document).ready(function() {
$("#uploadid3").change(function(e) {
// in jquery, e.files is null
if(e.files != null)
console.log("jquery: e.files is defined");
else
console.log("jquery: e.files is null");
// this works, prints the file name though
console.log("$('#uploadid3').val(): " + $("#uploadid3").val());
// this is undefined
console.log("$('#uploadid3').mozFullPath: " + $("#uploadid3").mozFullPath);
});
});
// this handler never gets called
function fileChangedInContentScript(e) {
alert("js content script: filechanged in content script called");
}
As you can see in main.js, I used jquery-1.8.0.min.js, downloaded from the jQuery website.
Note: I also tried these without jQuery included as a content script when I opened the tab in main.js, but no luck.
The conclusion is that mozFullPath is indeed empty when I access it from JS embedded in the HTML page and I cannot find a way to access mozFullPath from jQuery, nor can I find a way to add a onchange handler in load-form.html that’s defined in load-form.js
Second edit with onchange handler in the load-form.js content-script
I added the following code to load-form.js to catch the onchange event.
I also removed the jQuery content script from main.js
document.addEventListener("DOMContentLoaded", function() {
try {
document.getElementById("uploadid2").addEventListener('change', function(e) {
console.log("addeventlistener worked!");
console.log("e: " + e);
console.log("e.target: " + e.target);
console.log("e.target.files: " + e.target.files);
console.log("e.target.files[0].name: " + e.target.files[0].name);
console.log("e.target.files[0].mozFullPath: " + e.target.files[0].mozFullPath);
});
console.log('added event listener')
} catch(e) {
console.log('adding event listener failed: ' + e);
}
}, false);
This still outputs an empty string for mozFullPath:
info: added event listener
info: addeventlistener worked!
info: e: [object Event]
info: e.target: [object HTMLInputElement]
info: e.target.files: [object FileList]
info: e.target.files[0].name: test.sh
info: e.target.files[0].mozFullPath:
Is there anyway to acquire the needed permissions? How can I get my hands on that full path? I need the full path so I can pass it to an application the extension launches. (There are workaround solutions where I can do without the full path, but they decrease the quality of the extension)
fileInput.valueproperty is meant to be accessible to web pages so it will only give you the file name, not the full path – web pages have no reason to know the full path on your machine. However, as a privileged extension you should be able to access theFile.mozFullPathproperty. In this particular case you would do it like this:The big question of course is whether your code is allowed to access
File.mozFullPath. I suspect that a content script in the Add-on SDK won’t have the necessary privileges. The main extension code will have the privileges but getting to the input field from there is hard…