# Triggering Javascript from a Ruby form **URL:** \ **Category:** Rails\ **Created:** [September 4, 2010, 2:14am UTC](https://www.ruby-forum.com/t/triggering-javascript-from-a-ruby-form/194407 "2010-09-04T02:14:39Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![marsdragon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b2d939/32.png) [@marsdragon](https://www.ruby-forum.com/u/marsdragon)\ **Post date:** [September 4, 2010, 2:14am UTC](https://www.ruby-forum.com/t/triggering-javascript-from-a-ruby-form/194407/1 "2010-09-04T02:14:39Z")
Hello again, I’ve managed to hack together an uploader, but I need a progress bar to go with it. I ended up using FTP to upload, and got a way to find the progress while it’s uploading. I split that off into another function in the controller, which is all well and good. The problem is that I need to repeatedly call the how\_finished function while the file is uploading. The form goes to the uploading function, so I need another way to repeatedly call how\_finished. The best way seems to be with Javascript and AJAX, but I can’t find a good way of setting up and calling a Javascript function to get the information from the controller. Looking at other Ruby progress bars ([http://railsillustrated.com/screencast-file-uploads-progress-in-rails-passenger.html](http://railsillustrated.com/screencast-file-uploads-progress-in-rails-passenger.html)) it seems to be possible to call the controller with Javascript, but that also requires a separate module for Apache that doesn’t work for FTP uploads. I’ve been looking around at JSON, but I don’t really understand it or how to use it to do what I want. I’m pretty sure I have all the information I need in the program, the problem is getting it all together and I’m not sure if that’s even possible. Does anyone have ideas? ---
**Author:** ![marsdragon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b2d939/32.png) [@marsdragon](https://www.ruby-forum.com/u/marsdragon)\ **Post date:** [September 5, 2010, 9:12pm UTC](https://www.ruby-forum.com/t/triggering-javascript-from-a-ruby-form/194407/2 "2010-09-05T21:12:25Z")
A. Leek wrote: > I’m pretty sure I have all the information I need in the program, the > problem is getting it all together and I’m not sure if that’s even > possible. Does anyone have ideas? It may be too narrowly supported for what your trying, but you can go to the HTML5 route. Check out the File API: [File API](http://dev.w3.org/2006/webapi/FileAPI/), which shows the new javascript events that get fired when you do an upload. You can tie into the following and perform actions all on the client side: onloadstart onprogress onabort onerror onload onloadend If you need a more legacy (well, meaning it will support IE) solution you can look at SWFUpload. It has similar events, but uses Flash and Javascript to handle files and events. > **[Playbet88 : Daftar Agen Live Casino Online Uang Asli Terpercaya\<](https://swfupload.org/)** > > Playbet88 merupakan agen situs judi online terpercaya indonesia yang menyediakan banyak permainan gampang menang setiap saat. ---
**Author:** ![marsdragon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b2d939/32.png) [@marsdragon](https://www.ruby-forum.com/u/marsdragon)\ **Post date:** [September 6, 2010, 4:39pm UTC](https://www.ruby-forum.com/t/triggering-javascript-from-a-ruby-form/194407/3 "2010-09-06T16:39:36Z")
I think one of the things you might need is a ‘timer’, which will let your code ‘sleep’ before calling again your ‘how\_finished’ function. I have never done this but remember reading about it, I googled for ‘javascript sleep timer’ and one of the links I found was this: > **[Is there a sleep/wait javascript function for firefox?](https://www.daniweb.com/programming/web-development/threads/47199/is-there-a-sleep-wait-javascript-function-for-firefox)** > > I need to suspend processing in my script for a few seconds, and i am not sure how. Thanks, sj In order to communicate with the server from Javascript I would look into Prototype or jQuery. They simplify enormously the code in Javascript to be able to communicate with your server using AJAX. I hope this gets you started. ---
**Author:** ![marsdragon](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/b2d939/32.png) [@marsdragon](https://www.ruby-forum.com/u/marsdragon)\ **Post date:** [September 6, 2010, 5:09pm UTC](https://www.ruby-forum.com/t/triggering-javascript-from-a-ruby-form/194407/4 "2010-09-06T17:09:11Z")
pepe wrote: > I think one of the things you might need is a ‘timer’, which will let > your code ‘sleep’ before calling again your ‘how\_finished’ function. I > have never done this but remember reading about it, I googled for > ‘javascript sleep timer’ and one of the links I found was this: > [Is there a sleep/wait javascript function ... | DaniWeb](http://www.daniweb.com/forums/thread47199.html) Be it that he is using Rails he is certainly using Prototype, or perhaps jQuery, already. I have to disagree with the use of a timer (setInterval) in this context, considering the hugely evented nature of Javascript and what already exists out there.