Using form_set_error() to display error messages, the first argument is the name of a field.
1.$form['height'] = array( 2. '#type' => 'textfield', 3. '#title' => 'Height', 4.);Along with:
1.form_set_error('height', 'Error with height.');
Normally this is simple to define, but when using nested form items within fieldsets, this doesn't highlight the right item.
If the form was changed to nest the items:
01.$form['new'] = array( 02. '#type' => 'fieldset', 03. '#title' => 'New Image Size', 04. '#tree' => true, 05.); 06. 07.$form['new']['height'] = array( 08. '#type' => 'textfield', 09. '#title' => 'Height', 10.);Using:
1.form_set_error('height', 'Error with height.');
Notice the height is no longer highlighted?
The reason is that the field argument requires some formatting to make it work with nested forms.
Using a stupid '][' to tokenise the fieldname, we can specify which item to highlight.
1.form_set_error('new][height', 'Error with nested height.');
This gives us the proper feedback we wanted.
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