FileIFrameField with Parsing - php

Question

I'm using SilverStripe 2.4.7 and I want to add a method that parses the file which I have just uploaded with FileIFrameField. The thing that has me stumped is where to put this. I was thinking of the onAfterWrite method but the file only gets uploaded after the rest of the fields have been saved for the first time so I'm not sure this would work.
My question is: What is the best practice for this kind of thing?
Edit
I have this line of code where $filename is the path to my uploaded file but I keep getting a "no such file or directory error". I have even tried hardcoding in the filepath but get the same error.
$fh = fopen($filename, 'r');

Answer 1

the best way to parse a new file would be to hook into the uploadfield save method, for the FileIframeField you can do that by sub classing it and overwriting save()
(in SilverStripe 3 there is a new class called UploadField, in UploadField you would need to overwrite UploadField->upload(SS_HTTPRequest $request), and the file there would be accesable like this: $tmpfile = $request->postVar($this->getName()); )
below, and example on how to do it in FileIframeField:
class myFileIFrameField extends FileIFrameField {
public function save($data, $form) {
if (
!isset($data['FileSource'])
|| ($data['FileSource'] == 'new' && (!isset($_FILES['Upload']) || !$_FILES['Upload']))
|| ($data['FileSource'] == 'existing' && (!isset($data['ExistingFile']) || !$data['ExistingFile']))
) {
$form->sessionMessage(_t('FileIFrameField.NOSOURCE', 'Please select a source file to attach'), 'required');
Director::redirectBack();
return;
}
$fileContent = false;
if($data['FileSource'] == 'new') {
$fileContent = file_get_contents($_FILES['Upload']['tmp_name']);
}
elseif($data['FileSource'] == 'existing') {
$fileObject = DataObject::get_by_id('File', $data['ExistingFile']);
$fileContent = file_get_contents($fileObject->getFullPath());
}
if ($fileContent) {
// parse the $fileContent here
}
// if you want to still save the file into a relation,
//meaning if you want to have the actually FileIframeField behaviour still in tact then call
return parent::save($data, $form);
// other wise, if you do not want to save the relation and you don't want to save the file to the server
// thenn do NOT call parent::save, just do:
// Director::redirectBack();
}
}