Using Sinatra and ruby to interface to HTML buttons

Question

Disclosure: I know nothing about web programming

Background to problem: I have an environmental testing chamber testing embedded computers at various temperatures. It is controlled by a windows application. I can control the chamber via ruby and the Win32API interface of the control application. The chamber is far from my office and I would remotely monitor the state and trigger a change via a Web interface. Sinatra makes it easy to show the state via a web server.

My problem: I want to click on a button on the status webpage and send a command via Sinatra and Ruby to the application without switching to a different page. I cant find any examples or information for something like that.

The Answer: You can use Ajax(as in the accepted answer) but I am going with post and reload the page. It is a lot simpler but not as smooth.

Answer 1

I want to […] send a command via (the server) […] without switching to a different page

This is known as Ajax and is usually implemented using XMLHttpRequest.

Answer 2

Do you already have a form that POSTs to a sinatra handler and does what you want?

If so, you could easily make it ajaxy by using jQuery.

1. Add jquery.js to your public directory & require it from the layout

2. Add some js to post to your handler when your button is clicked.

   // assuming your form has id=myform
   // defines a callback on submission of the form #myform.
   $("#myform").submit(function() {
     //posts the contents of the form to /action using ajax
     $.post("/action", $("#myform").serialize(), function(result){
       // assuming result is a string of the updated data in html
       // and assuming that your data goes in an element with the id data-table
       $("#data-table").html(result)
     });
     return false; // prevents the form from submitting normally
   });
   

jquery docs for

• submit
• post
• serialize
• html