How to use JavaScript to fill a form on another page

Question

I am trying to fill out the fields on a form through JavaScript. The problem is I only know how to execute JavaScript on the current page so I cannot redirect to the form a

Answer 1

You're trying to maintain state between pages. Conventionally there are two ways to maintain state:

• Store state in cookies
• Store state in the query string

Either way your first page has to persist state (to either cookies or the query string) and the other page has to - separately - restore the state. You can't use the same script across both pages.

Example: Using Cookies

Using cookies, the first page would have to write all the form data you'll need on the next page to cookies:

 
     
 
 
     

         Setting cookies and redirecting...
     
     
 

... and the second page would then read those cookies and populate the form fields with them:

Example: Using the Query String

In the case of using the Query String, the first page would just include the query string in the redirect URL, like so:

 
     
 
 
     

         Redirecting...
     
     
 

...while the form would then parse the query string (available in JavaScript via window.location.search - prepended with a ?):

Example: With a Fragment Identifier

There's one more option: since state is being maintained strictly on the client side (not on th server side) you could put the information in a fragment identifier (the "hash" part of a URL).

The first script is very similar to the Query String example above: the redirect URL just includes the fragment identifier. I'm going to re-use query string formatting for convenience, but notice the # in the place where a ? used to be:

 
     
 
 
     

         Redirecting...
     
     
 

... and then the form has to parse the fragment identifier etc:

And if you can't edit the code for the form page

Try a greasemonkey script.