How to show/hide "printer-friendly version" link according to workflow states?

Question

There's a review content type on my site with a workflow: I use 'draft' and 'completed' workflow states.

I'd like to create a printer-friendly and pdf-version of 'finished' reviews only, so I'd like to hide the links generated by Print module in any other case. I tried to modify MYTHEME__preprocess_node() to achive this with this code, but it didn't work:

if($vars['field_review_workflow'][0]['value'] == '13'){ //sid of 'finished' state
  show($vars['elements']['links']['print_html']);
}else{
  hide($vars['elements']['links']['print_html']);
}

How could I do it properly?

Answer 1

One way of doing it is by using hook_node_view_alter(). For example, you would put the following code in a custom module called hideprint (see many tutorials online on how to create a custom module). Be sure to dpm() the array $build when you are testing the module to correctly check the value of field_review_workflow.

function hideprint_node_view_alter(&$build) {
  if ($build['field_review_workflow'][0]['#value'] == TYPE_VALUE_FOR_NOT_FINISHED){
    hide($build['links']['print_html']);
    hide($build['links']['print_pdf']);
  }    
}

Answer 2

There's a module for that! Workflow Fields

This module extends Workflow by allowing CCK node fields to be made invisible or read-only depending on the current workflow state. The workflow state form is extended to show all node fields with appropriate controls to hide and/or disable each field for that particular state.

This functionality is useful when a workflow moves among users who have different permissions regarding the document flowing through them. Which is the case in most every workflow we've encountered.

Answer 3

After all, my approach has been proved to be useful too. Hiding of these links can be done in MYTHEME_preprocess_node() but content array should be used:

if($vars['field_review_workflow'][0]['value'] == '13'){ //sid of 'finished' state
  show($vars['content']['links']['print_html']);
}else{
  hide($vars['content']['links']['print_html']);
}

Anyways, thank you all for the input.