How to add a field to Views table output with hook_views_pre_render?

Question

I have a view displaying node titles formatted as a table. In a custom module I'm using hook_views_pre_execute to do do a table join and add a field to the views query. (I cannot use a regular relationship in Views to accomplish the join, because it has to be a RIGHT JOIN).

When I inspect the resulting view object with dpm($view) in hook_views_pre_render, I can see that the objects in $view->result contain the string values of the node_title, nid, and field_myfield_value (where field_myfield_value is added via the custom module).

But how do I actually display field_myfield_value in the view? And more specifically, how do I make it a column of the table?

Answer 1

To take a different approach: you could add the field through the UI as normal, and use hook_views_query_alter() to change the join type:

function MYMODULE views_query_alter(&$view, &$query) {
  if ($view->name == 'my_view' && $view->current_display == 'foo') {
    $query->table_queue['field_data_field_myfield']['join']->type = 'RIGHT';
  }
}

That should get you the same effect with a bit less effort.

Answer 2

I guess the easiest would be to add i.e. the title field again in the views ui and then in hook_views_post_execute set $row->title2 (or whatever it would be called) to the value of your field.

Alternatively, you might try to describe the join to views, add the column in the ui "normally" and "only" alter the join. (Clive was faster with that one :)

Answer 3

I think Clive is right about using hook_views_query_alter being a little easier.

The views_join class also lets you define what is the left_table, left_field, (right) table and (right) field. Perhaps you would need to do more re-building in your hook_views_query_alter to get all the tables in the right place.

Considering the last part of your question "But how do I actually display field_myfield_value in the view?" hasn't been addressed yet, I think you might need to write a module to add the field to views. This article seems pretty straight-forward: http://www.grasmash.com/article/demystifying-views-api-developers-guide-integrating-views In it, they discuss hook_views_data() (adding data to a view via a custom table and extending the views_handler_field class to display the data.