How to change the feed link?

To which link are you referring? Feeds have many links, including links to the feed and links from the feed.

Hmm. That's weird because for normal RSS feeds, assuming you haven't modified the style in use on the feed, should use the standard method of producing RSS. See includes/modules/node/views_plugin_style_node_rss.inc (and the preprocess, where most of the work is done, is in modules/node.views.inc). There's nothing too out of the ordinary there. I can't think why nodeapi might not be getting called.

Might want to check caching? Anonymous caching covers RSS.

The problem, as far as I see it, is in views_plugin_row_node_rss.inc.

The $item object is created immediately after the hook_nodeapi "alter" op is invoked, and the $item->link and $item->title properties are added then.

Then hook_nodeapi "rss item" op is invoked, and array elements returned from that will be added to $item->elements.

So there's no way for hook_nodeapi "rss item" to alter the title or link. And in hook_nodeapi "alter", I don't think we can tell if the node is being built for RSS, ie messing with things there will have unfortunate side-effects.

I propose a small modification of views_plugin_row_node_rss.inc: move the addition of the $item->title and $item->link elements to AFTER hook_nodeapi "rss item" is invoked. I don't think that would affect anything else.

Patch against 6.x-2.10 attached.

As I just pointed out on this issue: http://drupal.org/node/174359 this change will only allow you to set the title, and not the link, as the link is not built from a property of the $node object. It may be possible to achieve a workaround by changing that, or by overriding the views-view-row-rss.tpl.php template, but it may require some hacking around. I suspect that finding a solution that can be patched into the views module itself will be difficult.

Yeah, sorry - I was mostly interested in changing the title.

Since we're patching the views plugin, I wonder if adding a custom hook would be a decent solution for you? Something like (untested):

  $item->title = $node->title;
  $item->link = module_invoke_all('views_view_row_rss_link', $row, $node);

  if (!$item->link) {
    $item->link = url("node/$row->nid", array('absolute' => TRUE));
  }

Then implement that hook in your own module to generate and return the link.

Thats the same code from drupal core. The item is also there.

    // Load the specified node:
    $item = node_load($nid);
    $item->build_mode = NODE_BUILD_RSS;
    $item->link = url("node/$nid", array('absolute' => TRUE));

    if ($item_length != 'title') {
      $teaser = ($item_length == 'teaser') ? TRUE : FALSE;

      // Filter and prepare node teaser
      if (node_hook($item, 'view')) {
        $item = node_invoke($item, 'view', $teaser, FALSE);
      }
      else {
        $item = node_prepare($item, $teaser);
      }

      // Allow modules to change $node->content before the node is rendered.
      node_invoke_nodeapi($item, 'view', $teaser, FALSE);

Yes, but this is the Views issues queue. The issue is how to modify the link in an RSS feed item generated by a Views feed display - not how to do so in core's RSS feeds.

Sure sure.

The reason why i posted it, was that we shouldn't change the code from the existing one in drupal.

Here's some code to alter an RSS item's title, creator, and link via a custom module.

/**
 * Implementation of hook_nodeapi().
 */
function mymodule_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  switch ($op) {
    case 'alter':
      // Alter nodes for RSS feeds.
      if ($node->build_mode == NODE_BUILD_RSS) {
        // This is where you can set your custom title and creator.
        if ($node->type == 'my_content_type') {
          $node->title = $my_custom_title;
          $node->name = $my_custom_creator;
        }
      }
    }
    break;

    case 'rss item':
      if ($node->type == 'my_content_type') {
        // This will get added to the RSS item's extra elements array, which can then be
        // accessed in the views preprocessor function below.
        return array('link' => $my_custom_link);
      }
      break;
  }
}

/**
 * Preprocessor for views RSS feed items.
 */
function mymodule_preprocess_views_view_row_rss(&$vars) {
  // If your view is generating multiple RSS feeds, you may have to change 'feed_1' to
  // match the correct display.
  if ($vars['view']->name == 'my_view_name' && $vars['view']->current_display == 'feed_1') {
    // This will use the link from the item's elements as the item's link.
    $vars['link'] = $vars['row']->elements['link'];

    // Remove the duplicate <link> entry from the item_elements. It probably wouldn't cause
    // any issues to leave it in; you'd just have two identical <link> tags for each item.
    $vars['item_elements'] = str_replace(" <link>{$vars['link']}</link>\n", '', $vars['item_elements']);
  }
}

Don't forget to clear your cache so that the preprocessor function gets recognized.

Oops, array_merge expects an array of arrays, so in hook_nodeapi() use this line instead:

        return array(array('link' => $my_custom_link));

And the preprocessor can be replaced with this:

/**
 * Preprocessor for views RSS feed items.
 */
function mymodule_preprocess_views_view_row_rss(&$vars) {
  // If your view is generating multiple RSS feeds, you may have to change 'feed_1' to
  // match the correct display.
  if ($vars['view']->name == 'my_view_name' && $vars['view']->current_display == 'feed_1') {
    // This will use the link from the item's elements as the item's link.
    foreach ($vars['row']->elements as $element) {
      if (isset($element['link'])) {
        $vars['link'] = $element['link'];
      }
      break;
    }
  }
}

Nice, no need to patch the views plugin. I was overlooking the availability of $node->build_mode in the "alter" op.

So this is fixed?

Thanks for the snippet in #11 & #12, strangeways. It works, but only when I remove the break; from the preprocessor function or put it inside the if-statement above it. i.e. like this:

/**
* Preprocessor for views RSS feed items.
*/
function mymodule_preprocess_views_view_row_rss(&$vars) {
  // If your view is generating multiple RSS feeds, you may have to change 'feed_1' to
  // match the correct display.
  if ($vars['view']->name == 'my_view_name' && $vars['view']->current_display == 'feed_1') {
    // This will use the link from the item's elements as the item's link.
    foreach ($vars['row']->elements as $element) {
      if (isset($element['link'])) {
        $vars['link'] = $element['link'];
        break;
      }
    }
  }
}

@dawehner, @strangeways

first off thank you for the alternate solution. However, in some cases doing the preprocess is too much (deh, clients!). Sorry for reopening this, but the 3.3 code solves this in a simple manner ( see line 156 ) and allows a simple change in hook_nodeapi as seen here

I am attaching a patch against 2.16 that moves the $item->link = url() bit before the node hooks are called and instead relies on $item->link = $node->link and could be considered a partial backport from Views 3.3