Use File API and file_transfer()

Here is a patch to do this.

I have rerolled this patch with the addition of #1391860: Add validation for meta tags as they conflict.

Fixed white space issue.

Last time, fixed issue when merged patches.

I think this is missing db_drop_field('site_verify', 'file');. The schema module is reporting "file: unexpected column in database".

Issues fixed.

- fixed meta verify was on wrong var.
- install schema fixed as pointed out by @mrfelton
- removed unneeded meta output at url.

Patch no longer applies cleanly I'm afraid.

A few things that need work too:

1. +++ b/site_verify.admin.inc
   @@ -174,27 +171,66 @@ function site_verify_edit_form($form, &$form_state, $record = array(), $engine =
   + * Helper function to validate meta tags
   + * @param  string $string
   + *   The meta tag string to validate.
   + * @return boolean
   + *   A flag to indicate if validation passed.
   

   Some blank lines are needed here to conform to docs standards.

2. +++ b/site_verify.admin.inc
   @@ -174,27 +171,66 @@ function site_verify_edit_form($form, &$form_state, $record = array(), $engine =
   +  // Pre pair saving this file.
   

   'Prepare'?

3. +++ b/site_verify.admin.inc
   @@ -174,27 +171,66 @@ function site_verify_edit_form($form, &$form_state, $record = array(), $engine =
   +  $destination = 'private://site_verify/';
   +  file_prepare_directory($destination, FILE_CREATE_DIRECTORY);
   

   What happens if I have not configured a private directory?

4. +++ b/site_verify.admin.inc
   @@ -174,27 +171,66 @@ function site_verify_edit_form($form, &$form_state, $record = array(), $engine =
   +/**
   + * Helper function to validate meta tags
   + * @param  string $string
   + *   The meta tag string to validate.
   + * @return boolean
   + *   A flag to indicate if validation passed.
   + */
   +function site_validate_meta_tag($form, &$form_state) {
   

   This is part of the patch at #1391860: Add validation for meta tags.

5. +++ b/site_verify.admin.inc
   @@ -212,10 +248,25 @@ function site_verify_edit_form_submit($form, &$form_state) {
   -      drupal_write_record('site_verify', $form_state['values'], array('svid'));
   +      db_update('site_verify')
   +        ->fields(array(
   +          'engine' => $form_state['values']['engine'],
   +          'fid' => $form_state['values']['fid'],
   +          'meta' => $form_state['values']['meta'],
   +          'file' => $form_state['values']['file'],
   +        ))
   +        ->condition('svid', $form_state['values']['svid'])
   +        ->execute();
   

   This looks like an unrelated change, at least partly. Why change from drw() to db_update()?

6. +++ b/site_verify.install
   @@ -128,3 +127,18 @@ function site_verify_import_ghs() {
   + * Add new column for file ID and drop old file_contents file.
   

   s/file/field/ ?

7. +++ b/site_verify.module
   @@ -177,11 +178,20 @@ function site_verify_get_engines() {
   +    return t('This is a verification page for the @title search engine.', array('@title' => $verification['file']));
   

   I don't follow this change.

Also, compare with #1230956: Support for Exportables (Features), which is (I think) incompatible with the direction taken here.