Add option for display a tag in teaser or full view only

Sorry for the late reply, I only checked the "My Issues" queue so I haven't seen the new posts here.

So you want an option for field tags with "teaser" and "full", like set in the display formatter options for fields of a content type (e.g. admin/content/node-type/story/display)?

Currently Linodef retrieves the field values by loading the node object (linodef-filter.inc, line 241, 271ff):

$node = node_load($nid);
$output = get_object_vars($node);
$output = $output[$fieldname][$valuenumber]['value'];

node_load() doesn't heed any display settings (teaser, full) and always loads the plain field value. Therefore a step must follow to get the teaser and full view for the field.

D6 does this with node_view (e.g. for the front page) but this returns only HTML (and this function is removed in D7 either). Additionally the function node_build_content returns an object containing the filtered field (which is already bad for our purpose) but doesn't heed the display options of a field (always the full field is loaded here, too, though the node state can be set to teaser or full).

So we have to use a function of CCK for this purpose. Yet I haven't had a decent look in their API so I don't know where CCK sets the display for its fields. Surely the Field API of D7 is a good start.
Or maybe you know already how to retrieve the display formatters set for a certain field of a certain node type?

I've searched Drupal for "node teaser full filter" (and other keyword combinations however this seemed to be the most promising) but there seems to be no way for querying the view of a node (teaser of full) with a function out of Linodef due to Drupals input filter behavior. I'm using node_load() and it doesn't include the display state since it doesn't matter for loading the node.

When the input filters are applied to a node then there is no information about the node view (teaser or full) available. This happens afterwards with the theme module.

See this for a discussion about Drupals input filter and contextual information: #67969: Support for separate image sizes for teaser and body.
Other module writers had similar assumption, e.g. #181856: Add teaser/full option for syntax arguments.

Maybe there is a way/function/object (changing the default workflow or caching things or similar). If someone knows one share your knowledge here, please. :)

Furthermore in D7 teasers will likely be overhauled, see #372743: Body and teaser as fields. If the patch turns out as it is planned and will be accepted then you will be able to define custom text as teaser so this feature requested here won't be needed.

Thanks for looking for possible solutions!

Filter macros uses hook_nodeapi to edit the node's content (for teaser and body view) directly in the database. This may be valid for filter macros (which isn't a filter module by itself but to support other filter modules) however this doesn't fit to a filter module (as far as I know): E.g. the dynamic replacement of filter tags won't work properly then.

Could you specify filter directive, please?

Ah okay, I understand. When using hook_nodeapi that could be applied at action 'presave' or 'view' (if view is applied before the filters what I don't know yet). However, lets using 'view' so the content saved in the database is untouched by Linodef (in comment #8 I wasn't aware of 'view' action). Then the function would be like this:

function linodef_nodeapi(&$node, $op, $a3 = NULL, $a4 = NULL) {
  switch ($op) {
    case 'view':
      if ($node->teaser) {
        // Delete body only tags
        $node->teaser = preg_replace('filter those tags with body view option by regex', "", $node->teaser);
      }
      if ($node->body) {
        // Delete teaser only tags
        $node->body = preg_replace('filter those tags with teaser view option by regex', "", $node->body);
      }
      break;
  }
}

This will only work for tags in node body fields and not in CCK fields. Furthermore it will have a performance impact on every node view so using 'presave' instead of 'view' might be better. But then Linodef would change the database content directly what isn't the purpose of a filter. Finally the most important fact against this method is the fact that Linodef won't know when to apply that search and replace and when not. It shall never be applied on body fields which use an input format that doesn't contain the Linodef filter. Currently I don't know how to retrieve this information therefore there is no patch.

The arg() function could be a solution. So arg(0) == 'node' could fit to check if we are currently in teaser or full view.

Already known issue:

• This likely won't work as intended with views that show full view nodes. Nodes shown in the context of a view (e.g. taxonomy, frontpage etc) will be always threaded as teasers.

However, is there still a need for this feature (tag awareness for the current context type (visibility options, CCK formatters)) so I should do further investigations?

Never mind, I got it. I've added an option called 'visibility' to control in what context the tag is visible.

This has been committed, too.