Drupal: use view output as node content - php

Question

I'm writing a Drupal 7 module to display child nodes of a module in the content.
Nodes have a field parent_nodes (node reference) where one ore more nodes are selected as parents.
First, I've created a view projects with a block view display subprojects, displaying nodes of type project with a field_parent_project contextual filter.
This is my module:
<?php
function projects_preprocess_node(&$variables) {
if ($variables['type'] == 'project') {
if (isset($variables['view_mode']) && $variables['view_mode'] == 'full') {
_projects_add_subprojects($variables);
}
}
}
function _projects_add_subprojects(&$variables) {
$nid = $variables['nid'];
$view = views_get_view('projects');
$preview = $view->preview('subprojects', array($nid));
$subprojects = array(
'#title' => t('Subprojects'),
'#label_display' => 'above',
'#weight' => 10,
//'#theme' => 'field',
'#markup' => $preview,
);
if (!isset($variables['content']['subprojects'])) {
$variables['content']['subprojects'] = array();
}
$variables['content']['subprojects'][] = $subprojects;
dpm($variables['content']);
}
This is working, adding the view display output to the node's content.
Only some things aren't working:
title (label)
weight do not change display position when rendered with other contents (it's always the first, above body).
If I uncomment the '#theme' => 'field' line, title is shown as a label, but nothing is rendered. This is because the field theme is used and I guess it needs #items and does not use the #markup element.
I cannot use a children nodes as reference, but only parent nodes.
The solution must be independent to theme, so no not answer "change your theme template" or similar
How can I show children nodes in node? I'm looking for a way to get something interpretable how a it is was a field

Answer 1

If you didn't already know, the Viewfield module allows you to specify a View as a field in your content type. This may save you some coding but you may not want a whole module to do such a specific task so...
If you want to continue with the custom code which you've written, then you need to re-structure your added content to the correct render array structure that Drupal expects. Try something like this:
$subprojects_view_output = array(
'#type' => 'markup',
'#markup' => $preview,
);
$subprojects = array(
'#theme' => 'field',
'#weight' => 10,
'#title' => t('Subprojects'),
'#items' => $subprojects_view_output,
);
With the above, the title/label for your field as well as the content of the field (the view itself) should show up. The code is untested so may not be 100% correct in terms of syntax and all but hopefully gives you a path to a solution.
EDIT: I tested the above and it does not work because in order to use the existing theme_field function it seems that Drupal expects more information required to render a field like the #field_name, #field_type, #entity_type, etc. as you should see in the warning messages.
Essentially, you are faking a field and you will need to provide Drupal with all the info it expects if you want to continue to use the built-in theme_field function, including all the variables as expected in the preprocess functions.
Alternatively, you can continue to use your original code and add a #prefix to get your title/label to render like this:
$subprojects = array(
'#weight' => 10,
'#prefix' => '<div id="subprojects-view">asdf:</div>',
//'#theme' => 'field',
'#markup' => $preview,
);
Then style the title/label with CSS accordingly. I didn't have any problems with the weighting as you described.

Answer 2

Thanks to #nmc, this is my final solution. If no results are found, it does not display the title. The check for results is done by if (count($view->result) == 0). Weight is working.
<?php
function projects_preprocess_node(&$variables) {
$type = $variables['type'];
if ($type == 'project' || $type == 'customer') {
if (isset($variables['view_mode']) && $variables['view_mode'] == 'full') {
_projects_add_subprojects_markup($variables);
}
}
}
function _projects_add_subprojects_markup(&$variables) {
$nid = $variables['nid'];
$view = views_get_view('projects');
$preview = $view->preview('subprojects', array($nid));
if (count($view->result) == 0) {
return;
}
$variables['content']['subprojects'] = array(
'#weight' => 10,
'#prefix' => '<h2>' . t('Subprojects') . '</h2>',
'#markup' => $preview,
);
}