Question

I’m trying to create some javascript validation for my web app and it’s all going pretty well except I do not want my script to look for something to validate all the time.

Let’s say I have two things I want to validate for but they do not occur on the same page. They are on '/page1' and 'page2' and I don’t want my validator for page1 to run on page2.

That should be possible through object literals right?
Something like this:

var validations = 
{
    page1validation :
    {
        init : function()
        {
            // validation page 1
        }
    }
    page2validation :
    {
        init : function()
        {
            // validation page 2
        }
    }
}

So I need to call these validation methods like validations.page1validation.init() and I guess I could do this with inline javascript in each haml view where I have a form that needs validation.

%form{:action => ""}
  %input{:type => "text"}
  %input{:type => "submit", :value => "save"}
:javascript
  $(function() {
    validations.page1validation.init();
  });

But there must be a better solution – I just can’t think of one right now. So what would you do to make sure the validator doesn’t try to validate all the time?

Oh and the inline javascript won’t work if I put the javascript at the bottom in my layout file…

Answer 1

The simplest way to do what you want is to make the forms different, either with a different id or class.

Then your validations can use that difference to “target” each form independently. You don’t need the extra “namespace” with that approach. Instead, you do something like this.

$(function() {
  page1validation();
  page2validation();
});

function page1validation() {
  var form = getElementById('form1'); // form1 is the first form
  if(!form) then return;

  // .. perform validations in form 1
}
function page2validation() {
  var form = getElementById('form2');
  if(!form) then return;

  // .. perform validations in form 2
}

Also, I’d advice you to invest some time in learning a js library like jQuery. It provides some built-in methods that will make the code above much smaller.