Intercepting a Form Submission

Hi,

Hoping someone can help a developer noob with a question --

Is it possible to intercept a form submission before it is processed, run a check on the fields submitted, and only complete submission if a certain custom condition is met?

The 'processFormData' hook appears to fire after the submission, so I can't use that.

I've also tried the 'validateFormField' hook, but I can't figure out how to use it -- i.e. how to access the properties in the Widget object that is passed through.

How would a seasoned developer handle this?

Thanks!

EDIT:

Now I'm extending the Form Class, writing a custom processFormData() method that runs my checks before calling parent::processFormData(). That sounds like something someone who knows what are were doing would do... :)

which properties do you need?

you can get a list of available properties looking at the widget api

http://api.contao.org/__filesource/f....php.html#a212

if you want to "invalidate" the widget passed to the validateFormField hook just add an error to it using the addError method

http://api.contao.org/__filesource/f....php.html#a255

hope this helps in some way

Thanks again, Ga.N -- the API is definitely making more sense to me lately (before it just scared me).

I don't know what I was doing wrong before (and I scrapped the code), but when I used the 'validateFormField' hook, it seemed that no matter what I tried, I was unable get any property values from the Widget object that was passed through.

For instance '$objWidget -> strClass' would always give me a blank value, even if the Widget item actually had a class applied to it.

Quote:

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Originally Posted by Medianomaly

Thanks again, Ga.N -- the API is definitely making more sense to me lately (before it just scared me).

I don't know what I was doing wrong before (and I scrapped the code), but when I used the 'validateFormField' hook, it seemed that no matter what I tried, I was unable get any property values from the Widget object that was passed through.

For instance '$objWidget -> strClass' would always give me a blank value, even if the Widget item actually had a class applied to it.

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you can't retrieve the strClass property because it is "protected" but you can retrieve the 'class' property (as you can see looking at the __get method of the Widget class)

Ahh -- I completely see what you mean now, thanks!

The FormAuto module uses EVERY single form interception there is. Both loading and rendering form widgets (to add content to the label and prevent submission with errors) and also post-process the form using the HOOK. Look at the formauto/config/config.php file to see how many HOOKS you need to process the form.