Programmatically adding fields to node submission form

Question

I need to add fields to a node creation/editing form programmatically. More specifically, I need to take already-generated form elements from another form and insert them into the node submission form.

That part isn't what's hanging me up though. My problem is that I can't figure out how to make the database hang onto the values submitted via the new field.

For example, the following code (copypasta'd directly from the API Quickstart page) creates a form element inside the existing node form just fine, but when I enter a value and submit the form, the value is not stored.

function [mymodule]_form_alter(&$form, &$form_state, $form_id) {
    $form['foo'] = array(
      '#type' => 'textfield',
      '#title' => t('bar'),
      '#default_value' => t('foo'),
      '#size' => 60,
      '#maxlength' => 64,
      '#description' => t('baz'),
    );
}

How do I alter an existing form in such a way that the submitted values 'take,' so to speak?

Answer 1

Add something like this to your hook_form_alter().

$form['#submit'] += array('mymodule_another_submit_handler');

Create that function and save your values from $form_state['values'].

function mymodule_another_submit_handler(&$form, &$form_state) {}

Where are they supposed to go? You might try to fire the submit handler of the other form so you wouldn't have to write so much code.

Answer 2

I hacked together a way of doing this. I have NO IDEA whether this is at all a good idea, or if I'm doing something blatantly terrible, so any code or ideas here are for information purposes only!

So, here's what I did (for a module called "webformta")

1. On my content type "Answer Key" I added a text field with unlimited multiple values enabled.

2. Inside webformta_form_alter() I add my fields:

       $form['foo'] = array(
         '#type' => 'textfield',
         '#title' => t('bar'),
         '#default_value' => t('foo'),
         '#size' => 60,
         '#maxlength' => 64,
         '#description' => t('baz'),
       );
    # ... and so forth for all the form elements as I want to add. 
   

3. Then, after I add the form elements I want, still inside webformta_form_alter():

       $form['#submit'][] = 'webformta_answerkey_submit';
   

4. Next, a separate submit function:

(This appends the responses given onto the ones already in the field without overwriting or deleting the old ones because the [] after $form['#submit'] above adds this onto the $form['submit'] array instead of replacing it.)

function webformta_answerkey_submit($form, &$form_state) {
    $foo = $form_state['input']['foo'];
    $values = $form_state['values']['field_answer_answers']['und'];
    $count = 0;
    foreach ($values as $value){
        $count += 1;
    }
    $form_state['values']['field_answer_answers']['und'][$count]['value'] = $foo;
    $form_state['values']['field_answer_answers']['und'][$count]['_weight'] = $count;
}

So, the values entered by your user in as many fields as you want can be stored in an array as one field with many values on the node submission form.

Anyone know if this is a terrible idea for any reason?

Answer 3

Your code just defines a form element. If you want to put the submitted value into the DB you have add a submitthandler and write appropriate code for it.

Maybe you consider adding a field to this node type as this does all the DB numbo jumbo for you for free. No coding would be required at all.