I use tampermonkey on mobile firefox. In userscript I use GM_download(url, name) to download file from url. When it start download same file in firefox the result of this is :
Hello.txt
Hello(1).txt
...
Hello(9).txt
I want to know how not download duplicates. Or way to block firefox download duplicate.
Or get directory list. If there file alredy exist dont download.
In bash(linux cml) you write ls ,in windows you write dir. But how it would be in userscript? If yo write file:///storage/emulated/0/Download/Hello.txt in your browser it show all files that you want (in this address is Hello.txt file). But I can't get this html or whatever is this via XMLHttpRequest
Ps: Sorry for my english
You cannot access the filesystem to check if some file exists. That would be pretty dangerous for userscripts - imagine you installed userscript that did that. Firefox doesn't even allow plugins to access filesystem AFAIK, so tampermonkey cannot provide that API.
What you can do is to remember the name of the downloaded file. Your options are:
localStorage - for example set localStorage[filename]=true and then check for that. But if you delete the file on your phone, this will prevent you from downloading it again
indexedDB this is nicer for saving data, but the problem is same as for local storage.
You can store the list of files downloaded with your user script, but cannot access the directory list I think.
Related
I'm wondering if it's possible to for certain JS files to be added to the web extension directory later?
Like say I have an app where users can select certain settings from within the app and those files (js and html files, images or blobs) are somehow added into the extension from the web. Like some sort of ondemand updater without using any native apps but it seems that upgrades are done by the appstores automatically.
I'm reading the files using ajax and adding them to indexeddb but because it could be more than one file that's getting messy.
Say a user wants a certain feature on the extension and there's an html page, js files and images then this gets downloaded to a certain folder inside the installed extension.
function download() { //only saves to downloads directory
var imgurl = "https://www.google.com.hk/images/srpr/logo11w.png";
console.log('download');
browser.downloads.download({url:imgurl},function(downloadId){
console.log("download begin, the downId is:" + downloadId);
});
}
I also tried the chrome download function above but that only works for the downloads folder not the extension folder.
Is there any way to make a custom updater?! I know we can't save to disk but any leniency or workarounds for the extension folder?! Even something silly like making a shell call to some dos (and linux/mac) thing that saves the file to the extension folder. I can fetch the files, just not save them.
Ok so I'll put it as an answer. This is the solution I'm leaning on which works for my scenario and I've listed some alternatives below:
Having the other files as separate extensions and giving the user an install link instead where they can install that extension, then those child extensions talk to the mother extension and they know the address to the resources in their child extension folder, so the mother gets the just the file locations from the children to load those assets from that folder. The child extensions are like bundles of those html and js with a background script which sends the addresses of these items to the mother.
https://developer.chrome.com/extensions/messaging#external
The drawback is that I'll have to see how that affects the urls like if I inject the html page from the child extension folder into the main interface using ajax then I can't use relative url's to any images in that 'cos the urls are relative to the mother extension folder.. I'll have to rewrite the child extension urls with the absolute paths into the html page to load images and js from the child extension html code which has relative urls.
Pros:
Cleaner and more persistent than indexeddb.
Files can be loaded normally from disk.
Cons:
User has to install separate extensions.
URL structure might be a bit confusing, need to rewrite urls if loading html from child. However this is only for image src's and where the javascript is loaded from so it's not such a big deal.
Other Possible Solutions:
Indexeddb which I'm already doing seems to be the preferred way of doing this but I really do not want to store every html asset in indexeddb. The upside is that while extensions need to be installed, this method can be done silently fetching and adding files without user interaction and indexeddb seems to be somewhat persistent. Might still end up using this because it is silent but having to load each asset from a database sounds like a nightmare.
The File Handle Api might have worked if I was working on Firefox only https://wiki.mozilla.org/WebAPI/FileHandleAPI
I haven't tried the shell copy, maybe if I fetch with ajax and then save to disk using some dos function and then doing different save functions for different OS systems.
Filesystem Api only saves to downloads and doesn't work for extensions anyways, so that's useless.
UPDATE
In windows there isn't any sudo, but this worked without admin priveleges for a subfolder (not on the C:\ root though). It would work for a linux only app very nicely. If I just wanted to save a file to a windows machine this might work.
Shell copy method would be to grab the contents of file with ajax from the local or remote location, output to DOS as a stream to save to file on windows. And do this for every operating system with a shell exec command or detect the OS and do that command. This way I can even put the files in the exact folder location.
Like say I make this sort of command from the contents:
//To append you can use >> instead of >
//folder seems necessary, can't save to root without admin
echo the content I want to save > C:\folder\textfile.txt
I thought of calling it using shell exec that only works in nodejs, so digging through the other answers on
How to execute shell command in Javascript
//full code to save file using javascript on windows
var shell = WScript.CreateObject("WScript.Shell");
shell.Run("echo content to save > C:\folder\textfile.txt");
The shell command doesn't seem to work. i can't find what this is for. There doesn't seem to be a shell command in regular javascript for windows. It seems to require IE ActiveX. Doesn't work with Firefox or Chrome.
Extensions can't modify their sources because the browser verifies them and resets/disables the extension if they change. Also, in Firefox the extensions aren't even unpacked.
The solution is actually quite trivial: save the code in any storage (localStorage, chrome.storage.local, IndexedDB) as a string and then add it in your extension page as a standard DOM script element. You'll have to relax the standard CSP a bit for that.
Used Filesaver.js plugins to download a text file. By default file download in My download folder. Need to store the downloaded file in a specific folder.
It is not possible... fortunately! Imagine what would happen if JS which runs in your browser could change your filesystem. The security hole would be so big that everyone would (and definitely should) stop using the Internet. Imagine a situation where I've built a website which onload fires the code which save a file in your filesystem. The file lands in your cron.daily directory (suppose you use Linux). What is the file doing? - you may ask (if you knew that it's been even saved :smiling_imp:). Nothing special - just looking for some private data and when finished it deletes random files from /usr/bin, /proc, /sys and maybe /etc - just to see what happens.
Do you see the problem now? The code which runs in your browser before you can react to this cannot have such power to save anything in your filesystem. The only thing you can do to give the user a file is to use a module like Filesaver.js which, in fact, does not have access to user's file system at all. It just makes a GET request to the file directly and it's the browser which downloads the file (because that's how a browser works). So the only way you can change the location of the downloaded file is to change the browser settings. No other way I know of.
The answer is No,
changing a directory is not possible due to security reasons in the
File API.
https://github.com/eligrey/FileSaver.js/issues/42
I'm making an extension that among other things edit a javascript file in an external editor (one on the user's computer). The extension has the javascript file saved in chrome.storage but it will ofcourse be a lot easier for the user to write code in their own editor.
This is why I decided to find something that creates a file on the user's filesystem which the user can find and edit it themselves, and if any changes are made, sync that back up to the extension (either by periodically checking or by using some listener).
I have looked around but nothing really seems to fit what I'm trying to do. Chrome's fileSystem API only works for chrome apps, not chrome extensions and the HTML5 fileSystem API does not allow for a simple filesystem URL to be requested and opened, instead it obfuscates the stored file and makes it practically impossible to edit that file easily.
Something else I looked at which might be more promising is letting the user edit one of the files in the directory where the extension is stored and somehow retrieving that content. This is however going to be a bit tough to implement with chrome's all the hash checking going on in chrome extensions not to mention the general modifying of those files' contents by the extension (possibly by hacking around by specifying your own update URL and "updating" a dummy javascript file that is going to be written to).
Is there any way to simply ask for a location to store a file and then allow the user to edit that file and sync it back up?
No, extensions are sandboxed from the real filesystem.
As you said, it's possible to read extension's own files; however, this is read-only for the extension and modifying those files on a deployed extension will result in Chrome detecting extension "tampering" and immediate disabling as a precaution.
The only way for a Chrome extension to escape the sandbox is, as wOxxOm suggested, a Native Host module. Note that this cannot be distributed in Chrome Web Store with the extension; it needs a separate installer.
Alternatively, you could use some sort of cloud storage with API to access it; e.g. a user could store something in a Dropbox subfolder, and your extension can authorize access to it via Dropbox API. Unfortunately, there is no "native" solution like syncFileSystem for Apps.
Is there a function in the Chrome API that gets the most recently downloaded file?
My goal is to grab this file, copy it, and save it to a different location since in Chrome you cannot change the default download directory for specific file types/websites:
How to set download location via chrome api
Is this idea feasible?
The chrome.downloads API just became stable with Chrome 31. It allows you to deal with all download interactions, like getting the filename and the MIME type. I'm not sure if and how you can copy and move files on the user's system by a Chrome extension.
For your goal you could use the onDeterminingFilename function and alter the filename to contain subdirectories, like putting all .jpg files into Downloads/images/.
I want to read the data from a file that is distributed with my CRX (it's in a subfolder myfiles) into a javascript variable. (It is not on the filesystem. It's inside the crx)
I understand I can use XMLHttpRequest, but what would the url be? Would it just be a relative one? or a file:///WHAT_GOES_HERE/myfile.txt? Since this is a packaged app, what would go after the "file:///"?
I don't want to use chrome.runtime.getPackageDirectoryEntry because that requires Chrome 29 or later and some of my users might not have that version
How would I do this?
This is a chrome packaged app, not extension
To get the URL you should use chrome.runtime.getURL.