Set default values for a field from a node

Question

In Drupal, when you create a field, you can specify the default value for a field. For example, if you have a field called price, you can set the default value to be 400. When the user creates a new node, 400 is the default value, but s/he can change it to whatever s/he wants.

Is there a way to link this default value to a node field value.

For example, lets say on node/12 I have a field called "price default". If the user enters 500 on this field (on node/12), the default value of the price field (for all new nodes) will change from 400 to 500.

Answer 1

Ahmed was close, but to take it all the way you need to fetch the field's value:

function MODULENAME_form_alter(&$form, $form_state, $form_id) {  
  if ($form_id = 'YOUR_FORM_ID_HERE') {
    // Fetch node that has default value
    $node = node_load($nid);
    // Fetch the value from price field
    $node_wrapper = entity_metadata_wrapper('node', $node);
    $field_val = $node_wrapper->field_price->value();
    // Set fetched value as default
    $form['field_price'][LANGUAGE_NONE][0]["value"]['#default_value'] = $field_val;
  }
}

• I am itching for a clean way to avoid having ['und'][0] in there, as these values can change with localisation, but this would still work.

Answer 2

You can use hook_form_alter to set default value of your field by select the last value of it

function MODULENAME_form_alter(&$form, $form_state, $form_id) {
    $form['account']['status']['#default_value'] = '0';
}

Answer 3

You actually can. Before setting the price field's default value, do a node_load($nid) (You must know the node's id), it should return the complete node object inclusive of the fields. You can find the value of price_default from that and set the default value of price field accordingly.