Is there a tutorial on creating field types?

Have you seen this: http://ellislab.com/expressionengine/user-guide/development/fieldtypes.html

I did find that early on in my searches but it doesn’t go into much detail for someone who has never built a field type before.

However having spent a morning messing around with code, reading it again it’s starting to make more sense.

Thank you, I’ll give it another bash and see how I get on.

Ok, having had some success with a fairly simple field type, I’m now working up to what I actually want to implement and I’ve got myself stuck again.

Take this, (very reduced!), code:

1 class my_field_type_ft extends EE_Fieldtype {
2   function display_field($data)
3    {
4        $this->settings['test_var'] = 'Testing';
5 
6       echo "settings field names: ".$this->settings['test_var']."";
7        return 'form html for publish page';
8    }
9    
10   // --------------------------------------------------------------------
11   
12    function save($data)
13    {
14        echo "test_var: ".$this->settings['test_var']."";
15        die;
16        //return 'Return string to save';
17    }
18   
19    // --------------------------------------------------------------------
20 }

display_field($data) is the function that shows the field type on the publish page, and save($data) saves the data when the submit button is clicked.

I want to store a value in $this->settings, (or some other variable), when the publish page is built that I can then test in the save function.

Line 4 sets a value, and line 6 will correctly write it to the screen on the publish page, but by line 14 it no longer exists.

It’s either a scope issue, or the fact that by the time the save function runs it is a different instance of the class so the variables are empty.

Is there any way to force $this->settings to be saved at the end of display_field, or is there another method I have not thought of yet? (I’ve been looking at this for a very long time, so could well be missing something glaringly obvious!)

Thanks.

Ok, I’ve managed to get this working in a different way involving more code than I was hoping for, but it’s working. I can refine it later when I have time.

I’m now doing some crunching through the $_POST data to work out what has been submitted and turn it into the data that will ultimately be saved in the DB. This logic is now in the validate function and I am no longer over-riding the save function.