problem with hooking node add/edit form

Question

I wanted to hook node/add/patient-history form because I wanted to add ajax in that form.

Before adding Ajax I wanted to get field names correctly. So I tried this:

function ajaxify_form_patient_history_node_form_alter(&$form, &$form_state, $form_id) {
  $form['field_history_patient_id']['und'][0]['#value'] = "Hello";
  // I also tried 
  $form['field_history_patient_id']['#value'] = "Hello";
}

They are not working.

I am not sure if I am taking the field names incorrectly or missing something else.

Hook name seems to be correct because this one works:

  $form['actions']['submit']['#value'] = t('Save History');

I found some similar questions on stackexchange but with no answers.

Any advice/links appreciated very much. Thank you.

Answer 1

I use this in my module to prepopulate the forms with data when hooking on FORM_ALTER:

$form['field_history_patient_id'][LANGUAGE_NONE][0]['value']['#default_value'] = "whatever";

But when defining the form it is enough to do :

$form['field_history_patient_id']['#default_value'] = "whatever";

Answer 2

Check Why is hook_form_alter so messy in d7?.

If you have Devel module installed, you can check your fields with dpm($form) in your hook or you can use echo '<pre>'; print_r($form); echo '</pre>'.

I hope this will help you to track down your element hierarchy and find out the correct attributes.

Answer 3

You need to set the #default_value property. $form['field_history_patient_id']['#default_value']