How to serve html+js in node.js from virtual memory? - javascript

Context
I am making an in-browser html/js editor, for this I am using memory-fs (virtual memory) with Webpack and webpack-html-plugin to bundle the files that the user creates in the editor. The files are written to virtual memory in order to avoid I/O operations, which would happen whenever any user compiles their program in the in-browser editor.
Problem
Using node.js, how do I serve the resulting html+js-bundle?
I know I can use
express.get('/:id', (req,res) =>...)
to make dynamic routes which I can map to the correct output. I also know I can use
res.send(html-string-from-virtual-memory)
to serve the html as string. However, I don't know if this will serve also the bundled javascript which will be included in the html file with a script tag like this:
<script type="text/javascript" src="index_bundle.js?a9d6aa105c772d02e0f9"></script>
What will happen when the browser gets to this part? Will it make another request that I will have to handle on the server side with another .get()? What should it look like? I have no idea.
Node.js is made to serve static files from a /public path from disk to handle it easily, so I'm struggling because it doesn't allow me to handle the file-retrieval manually (it just asks for the path and handles the files itself) in order to get the files from the virtual memory.

Yes, when the browser sees the <script> tag, it will make a new request for the JavaScript file. In Node, you can make a new express.get() listener and send the JavaScript just like you send the HTML.
res.send(javascript-string-from-virtual-memory)

Related

Run HTML file via Bash? Possible?

I have a html file that when run in a browser such as Chrome and that contain javascript instructions, it sends the "emit" message to my websockets server and displays the value on that page.
Is there a way to call this same html file from a bash script as I'm wanting to insert data into a MySQL database which will ultimately call that html file to send an update to the websocket.
Hopefully that makes sense but hopefully there is a way to do it too :)
If you are only focused on rendering the HTML page (and not interacting with it via buttons or something) you may find this link helpful: Running HTML from Command Line
If you try to execute javascript instruction in your server without using a browser, I recommand you to use Node.JS with a real js script without html.
Otherwise you can try to run an html file with js instruction inside using something like phantomjs but I think is less performant than using Node correctly.
EDIT
It is Javascript yes, but I need to "Import" the socket.io.js file into the same script I have created and my browser I'm having to use doesn't support the new Javascript import methods. So I'm writing as HTML which calls the Javascript, otherwise I would use nodejs
I think you can import the socket.io lib in node application using npm.
https://www.npmjs.com/package/socket.io
The documentation says that you can use a client inside a node script too :
Socket.IO enables real-time bidirectional event-based communication. It consists in:
a Node.js server (this repository)
a Javascript client library for the browser (or a Node.js client)

Download external website with nodejs (including resources)

I want to download a webpage, say http://www.stackoverflow.com with nodejs. Meaning that I have an offline copy of the static page. It has to download the resources (like styles, javascript files, images etc) and update the references to local ones.
In any case I want an offline page that once opened looks exactly like the real page. Just like what happens when I choose file->save in a web browser.
Basically I want to replicate the function of
wget --page-requisites
(Although this does not download css and images properly)
The background is that I want to execute Javascript on an external website. This is (rightly) not possible due to cross-domain-policies. To avoid this, I just want to download the website and statically host it myself, execute my Javascript analysis-code and then delete it.
I'm sort of spit-balling on a solution that could work for this:
A package like js dom could be used to grab all the page's script, link, img, etc's source URLs. You could then GET and save each of those resources to your local environment and replace their src attributes with a new URL that points to your local copy. Then you could stringify the resulting HTML and save that as well. Then just serve the containing directory statically in Node.
Maybe just running wget --page-requisites from within node is the easiest solution?
I'll be interested to know what the final solution to this is. Hopefully something I said helps.

Failed to load large JavaScript file ExpressJS after uglifying

All my scripts are compressed and minified used uglifyJS:
The size of this file "app.min.js" is 982.1KB however when I tried to run the node server and open the app in the browser It's stopped in 502kB
and after some while
I don't know what happened there, Is there any limitation on Javascript file '502kB' ?
what I miss
I think this article may help you, it is all about nodejs server serving static content, so nginx is recommended to do this purpose.
If you have to use nodejs server then you should make all files smaller in terms of size, no need for example to minimize libraries files as jquery since it is already minimized, scripts should be minimized only, you can even minimize all libs files into one javascript file called libs.min.js as example and the rest of your scripts in another file called script.min.js.

Using javascript to move a file on a server

So I have this html page. Inside of it is a bit of javascript code that talks to a flash application.
During the flash application's lifecycle, it'll save a file to a place on the server using the javascript on the html page.
How can I use javascript to take the file I just saved and move it to a different location?
You cannot. Javascript works on a client and don't have an access to the server's filesystem.
You can only trigger a script on the server that does that.
As you said you have node js installed and running on the server,it is possible for you to move a file using the nodejs filesystem api: http://nodejs.org/api/fs.html#fs_fs_rename_oldpath_newpath_callback
For this to work you would need to monitor and detect when new files are saved in a certain folder, which should be possible using: http://nodejs.org/api/fs.html#fs_fs_watch_filename_options_listener
Happy coding!

Does Javascript support the ability to get a directory listing?

I want to upload a bunch of image files to a directory that I've set up on my ISP's free hosting service. It's something like http://home.ISPname.net/~username/subdir.
I want my Javascript code to be able to get a directory listing and then preload whatever it finds.
But getting such a thing even possible? My impression is not.
I suspect I will have to instead rename my files to 00000.jpg and upward, and attempt to detect what files are there using try.
FYI, I know that my ISP does not support using FTP protocol to get a directory listing.
Thanks for any help.
Under the assumption that your JavaScript code is code on your pages and not code on your server, then no, there's no API provided for JavaScript in a web browser other than a server-side API accessible via HTTP that you would create yourself. If the directory full of files is on the server, then it's going to have to be some server-side code that delivers the directory listing anyway. You could write such code in the server-side programming environment of your choice (including a server-side JavaScript solution, if that's what you want and if such a thing is possible at your ISP). As Pekka notes, it may be possible to simply enable directory browsing in your server, though that's generally a fairly low-level service that will deliver some sort of HTML page to you, and parsing through that might be somewhat painful (compared to what you could get from a tailor-made service).
Another, simpler thing you could do would be to upload a manifest file along with the other image files. In other words, create the directory listing in some easy-to-digest form, and maintain it separately as a simple file to be fetched.
javascript not suport directory listing in a direct way. but you can create a directory dumper php file, and send via AJAX.

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