Updated Wed, 18 July 2012 [earlier Updated Tue, 22 Nov 2011]
drupal external links filter (elf) module
http://drupal.org/project/elf 6.x-3.0-alpha2 on 6.22
starting from 6.x-2.1 on 6.14
Elf Module
Main function:
Adds little icons to links, so that you know it's a link.
Example function:
Making links more prominent without chaning the actual link title's style. This is useful, for example, if your theme does do not show overly prominently.
Manage:
Site configuration > External links filter
Here you can administer two effects:
- add a standard icon to all external links different for (link and mail link)
- make all external links open in a new window
Site configuration > Input formats
- check-mark the filter types that should use this external links filter
Test link: http://en.wikipedia.org/wiki/Wikipedia:Icons
But I'm not seeing any icons. Changing themes to see if the cause might be there. But it's the same on Garland. Checking documentation: there is no documentation. I wonder what I'm missing here. Check list: Permissions are set. What else. Checking Site configuration >
Input formats. Yes, it needs to enabled in the input filter(s). It works now.
Another module exists with similar functionality: http://drupal.org/project/extlink. That is based on java script, not filter.
The elf filter approach appears to have one advantage, the links can be made to behave differently according to input formats/user groups. The extlink module can be modified to behave differently in different settings as well.
Elf error
Update: this error has a patch now. Details see below.
20 November 2011, using Drupal 6.22, Elf 6.x-3.0-alpha2, PHP 5.2.22, MySQL 5.0.92-community.
This came up as I edited content. Obviously related to the contributed Elf external links filter module.
Links will not show on the page, after a node has been created or edited. Existing nodes remain unaffected as long as no cron has been made (like checking for site updates). Clearly after cron and updating other modules *all* site links disappeared and all pages have the error message, one for each link. Unpleasant business.
The error is discussed (update: plus patch) at http://drupal.org/node/1261568. It is categorised under D7, yet the actual issue is based on updating from 6.x-2.x to 6.x-3.x. Here, a contributor says that the module requires PHP 5.3.6 or higher. Another user has the same problem with PHP 5.3.8. My site uses PHP 5.2.22, which, in fact is quite with the times.
Extlink module
For the moment, disabled the elf module. Replacing it with the extlink module http://drupal.org/project/extlink. After upload, find it under module heading "User interface".
After cache flush, the links reappear: www.drupal.org/node/1261568.
However if the tag is enabled and anyone uses it without http://, it will not register as an external link.