javascript - .js.erb VS .js

Question

What is the advantage to putting you javascript for your rails app into a .js.erb file instead of just throwing it in your application.js file? I have a create button for businesses so should I put the code into a create.js.erb file or put it into my application.js using:

$("#business_submit").click(function() {}

All that aside is that I have my create button

    $('.error').hide();
$("#business_submit").click(function() {
    // validate and process form here

    $('.error').hide();
    var name = $("input#business_name").val();
    if (name == ""  || name == "Required Field") {
        $('#namelabel').show()
        $("#business_name").focus();
        return false;
    }
    var address = $("#business_address").val();
    if (address == ""  || address == "Required Field") {
        $('#addresslabel').show();
        $("#business_address").focus();
        return false;
    }
    var city = $("#business_city").val();
    if (city == "" || city == "Required Field") {
        $('#citylabel').show();
        $('#business_city').focus();
        return false;
    }
    var state = $("#business_state").val();
    if (state == ""  || state == "Required Field") {
        $('#statelabel').show();
        $("#business_state").focus();
        return false;
    }
    var zip = $("#business_zip").val();
    if (zip == ""  || zip == "Required Field") {
        $('#ziplabel').show();
        $("#business_zip").focus();
        return false;
    }
    var phone = $("#business_phone").val();
    if (phone == ""  || phone == "Required Field") {
        $('#phonelabel').show();
        $("#business_phone").focus();
        return false;
    }

     var category = $("#business_business_category_id").val();
    if (category == " - Choose one - ") {
        $('#categorylabel').show();
        $("#business_business_category_id").focus();
        return false;
    }
    $("#new_business")[0].reset();
    $("#new_business").toggle();
   return false;
});

This works great in my .js file but when I click create it doesn't actually send the information they typed in the form to the database. So I tried copy pasting the code into the .js.erb file. Now the form is submitted to the database when I click create, but half the javascript isn't working. The $('.error').hide(); isn't hiding my errors and they are all showing up regardless. $("#new_business")[0].reset(); isn't reseting my form, and there is no validation checks when I click create. So I either have a fully functional form that doesn't submit or one that submits but isn't really functional. Which one should I try to get working?

I see a lot of code with $.ajax but I can't figure it out for the life of me. I tried for a bit and I started getting some forgery protection errors in rails which is a whole other problem.

Answer 1

.js.erb files are for controller actions, such as create, when you want javascript to be executed when the action completes. For example, when you want to submit a form via ajax and want display an alert when everything is done, you would put the

$('#business_submit').click(...)

in your application.js or *.html.erb, and your create.js.erb could look like this:

alert('New object id: ' + <%= new_object.id %>);

This way, the javascript that is getting returned to the browser can be first rendered by Erb, allowing you to insert custom strings/variables/etc just like you can in .html.erb templates.