Alter input of form before it is submitted

Question

I'm creating a multilingual Drupal site and trying to implement a search function, that only displays results in the current language, that the user is viewing the site through.

Using Drupals own searchfunction at /search/node it is possible to select which language to search for through the "Advanced search" options, and it works perfectly. However, I dont want to expose these language selectboxes, I just want it to only search in the current language automatically.

What's the best option to do this?

I have one solution where I create a hook_form_alter function, that sets the #default_value in the language selectboxes to the current language, and then I hide the whole "advanced options" with in css. This doesnt seem very right though.

I think the most clean solution would be to hook into Drupals form-processing process and append ex "language:en" to the input text, but I cannot get this to work.

Does anyone know if it is possible via one of the Drupal form related alter functions, to get a hold of the input text and alter it before drupal does its final processing of it?

Answer 1

To answer your question specifically, while using 'hook_form_alter', you have a referenced variable called '$form_state'. This stores the values in the form, and any change there will be passed further.

Also,

I think setting a default value and hiding the field is a good solution as any, only, if you are hiding it you should do it server side, while altering the form. The same field you are setting the default value to. like this: $fieldname['#type'] = 'hidden'.