I recently found out that Go compiles down to WebAssembly. Cool!
As per this Go doc, the Go toolchain itself is written in Go.
This made me think, can the Go compiler run in the browser? Can I make a website which given a file path through an upload button (though, without uploading anything), can compile a Go project and return the executable as a "download"?
The end result I'm looking for is an executable file saved to disk, not for the Go code to run in a browser, but I don't need the exact scenario above to be followed as long as that is the final result.
If this is possible, what are the limitations, if any?
Additional resources I have looked at:
A compiler from Go to WASM on GitHub
Someone working on a game where entered Go code runs in the browser
EDIT: I have started work on this, based on a similar project. The repo can be found here: https://github.com/TR-SLimey/IBGC
It is possible, but it's hard to do.
You can't access files using WebAssembly. Instead, you need the user to drop a folder inside the webpage and use the File and Directory Entries API to get the files and their contents.
But the real problem is passing the files from JS to WASM and vice-versa. You'll also need to replace in the compiler source code all the calls to the Go standard library that would access files to calls to JS functions. Those function need to access the WASM memory directly. You will need to modify the compiler quite a bit.
To download the binary, you can create a Blob, use URL.createObjectURL() to get an URL to that blob, create an <a> element with .download = true and .href = <the blob URL>, and then .click() it.
The performance might be worse than running the Go compiler directly, but other than that it should work just fine.
Related
I am having trouble using dartdocgen and dartdoc-viewer to pump my JSON files to the browser. I have had success getting all the JSON files from my application but haven't had any success actually viewing them in the browser. Based on my research, the best way to do this is hosting dartdoc-viewer on a local server as mentioned by this document:
https://www.dartlang.org/tools/dartdocgen/#deploy
However I just cannot seem to get it to work following these directions (I would like to approach it via dartium):
https://github.com/dart-lang/dartdoc-viewer/
I understand that once I am able to run pub build and compile to javascript that I dump the client/build folder into my server along with the docs folder under the URL, I am golden. That's where the issue is, how to get it from the docs folder to javascript to the browser.
I would like to be able to use dartdocgen to it's full potential so can I get some ideas?
Just run dartdocgen --serve .
see https://www.dartlang.org/tools/dartdocgen/#view-locally
Is not what you are looking for?
Dear Haskell community I have written my first gui application and decided to use
threepenny-gui to do so.
The task is the following search the files in a given folder for matches and provide links to open those files. In addition I made nice parse and render function as the files (mostly) have a special formatting.
But now I have stumbled upon a problem - most browsers prohibit links to local files by href="file://localhost/home/user/folder/file.pdf" being opened, for security reasons, which I do understand and find completely sensible.
I tried to use href="./file.pdf" when the program and the file are in the same folder, which also doesn't seem to work.
The code of the whole application is available at github/epsilonhalbe, I run it in a folder and access it via a browser at localhost:100000
The HTTP server provided by threepenny-gui will serve up static content from the directory you specify in tpStatic. Put your files in that directory, and make your links' paths be relative to it, and you'll be good to go!
As of threepenny-gui-0.4.*, there are also two functions loadFile and loadDirectory that can be used to serve a local file or directory at an automatically generated URL. This can be useful if the tpStatic field is not enough.
Well, using HTML5 file handlining api we can read files with the collaboration of inpty type file. What about ready files with pat like
/images/myimage.png
etc??
Any kind of help is appreciated
Yes, if it is chrome! Play with the filesytem you will be able to do that.
The simple answer is; no. When your HTML/CSS/images/JavaScript is downloaded to the client's end you are breaking loose of the server.
Simplistic Flowchart
User requests URL in Browser (for example; www.mydomain.com/index.html)
Server reads and fetches the required file (www.mydomain.com/index.html)
index.html and it's linked resources will be downloaded to the user's browser
The user's Browser will render the HTML page
The user's Browser will only fetch the files that came with the request (images/someimages.png and stuff like scripts/jquery.js)
Explanation
The problem you are facing here is that when HTML is being rendered locally it has no link with the server anymore, thus requesting what /images/ contains file-wise is not logically comparable as it resides on the server.
Work-around
What you can do, but this will neglect the reason of the question, is to make a server-side script in JSP/PHP/ASP/etc. This script will then traverse through the directory you want. In PHP you can do this by using opendir() (http://php.net/opendir).
With a XHR/AJAX call you could request the PHP page to return the directory listing. Easiest way to do this is by using jQuery's $.post() function in combination with JSON.
Caution!
You need to keep in mind that if you use the work-around you will store a link to be visible for everyone to see what's in your online directory you request (for example http://www.mydomain.com/my_image_dirlist.php would then return a stringified list of everything (or less based on certain rules in the server-side script) inside http://www.mydomain.com/images/.
Notes
http://www.html5rocks.com/en/tutorials/file/filesystem/ (seems to work only in Chrome, but would still not be exactly what you want)
If you don't need all files from a folder, but only those files that have been downloaded to your browser's cache in the URL request; you could try to search online for accessing browser cache (downloaded files) of the currently loaded page. Or make something like a DOM-walker and CSS reader (regex?) to see where all file-relations are.
I was using wget with system call (c++) to save a webpage from internet to my HD in a program. Now I want to use wxWidget to do the same. Is there anyway I can do that and still have the generic behaviour of wget? (i.e. i give a link to a pdf file n then a pdf file is saved)
I found this link http://wiki.wxwidgets.org/Download_a_file_from_internet
but I have no idea how to convert wxString to a pdf/mp3 file according to the url entered.
Could anyone help please. I am working on an open source project for the first time and I encountered this wxWidget just now
If you are happy using wget with a system call, then why not continue to do so?
wxWidgets is a GUI framework, with a lot of extra convenience functions included. You don't HAVE to use them. You can still use whatever C++ features, utilities and packages that your are familiar with.
Here is a link to Wget for Windows
You can use wxHTTP (as described here) or use wxURL and GetInputStream()
I have a Flash AS3 application that uses FileReference.browse() to request a SWF from the user. If the chosen SWF is AS3, I'm good to go. However, if it's AS2, I need to load it into an AS2 wrapper first (so my app can alter it). All of these files (including my app and wrapper) are intended to exist locally on the user's machine, but the file they select can exist in any directory. So to be clear: Main application (AS3) -> Wrapper (AS2) -> User's file (AS2)
I know how to get the uploaded file's ActionScript version from the Loader's loaderInfo.actionScriptVersion variable, and that's working correctly. My issue is how to pass the file from the AS3 application to the AS2 wrapper so it can load it.
My first thought was to dump the ByteArray from the FileReference's load() function into a SharedObject "cookie". This method seemed pretty bad from a user-experience point of view, but it seemed most likely to work. However, I've been unable to find any method within AS2 to load the ByteArray as a movie (in fact, AS2 doesn't even seem to have a ByteArray class). So the first potential solution to my problem would be if anyone knew of a method for loading a movie from a ByteArray in AS2.
My second thought was to pass the uploaded file's path to my wrapper via the already-setup LocalConnection bridge, and then just have it load the file from that. However, I can't find any way to get the file's path, and my Googling suggests the security model intentionally prevents it. Not to mention, I'm not sure I can load an arbitrary file from the user's machine.
My "hands up in the air; I give up" solution was to just create separate buttons for loading AS3 and AS2 files (leaving it up to the users to guess which it is!) and have the AS2 button actually within the AS2 wrapper. However, it looks like AS2 doesn't have a file browsing uploading API, and the PHP-hybrid solutions I've found aren't an option (because this is meant to be run locally).
So, I would be eternally grateful if anyone could point me in the right direction for solving any of these three roadblocks. Alternative workarounds are of course welcome.
(Edit)
Ok, I found the documentation for AS2's version of the FileReference class. It supports the same file-browsing capability, but does not support directly loading the selected file into the SWF.
However, the security sandbox doesn't seem as strict for local files as I expected, and it looks like I can load any SWF on the user's machine once I have a path to it. So I should be able use JavaScript and an HTML form with a file input to get and pass the file path to my application. It's not ideal having to do all of this from within a web browser, but it should work. If it turns out satisfactorily I'll submit it as an answer.
(Edit 2)
Scratch the HTML-form idea. Looks like the path is hidden from JavaScript for the same reasons Flash hides it. The only option I can think of now is to have the user copy and paste the path to the file...
After reading over your post, you may be able to retry one of your previous attemps with some new information. Actionscript 2 DOES have a method for looking up files from a browser, same as AS3 does. AS2 also has a FileReference class. Check out the documentation here:
http://help.adobe.com/en_US/AS2LCR/Flash_10.0/help.html?content=00001040.html
Also, here is a tutorial:
http://markshu.ca/imm/flash/tutorial/fileReference.html
Well, all of my other leads have dried up, so I'm submitting the two answers that will actually work, although neither is ideal:
A) Use Adobe AIR, which will give more access to the filesystem (such as for getting path info) at the cost of requiring the separate AIR runtime to be installed.
B) Have the user enter the path to the file themselves (cumbersome for the user)