Getting nested set model into a but hiding “closed” subtrees

Question

Based on Getting a modified preorder tree traversal model (nested set) into a

One of answers gave right code to display full tree. What i need is to alway

Answer 1

Based on answer by satrun77. I created a helper for symfony + doctrine + nestedset (http://www.doctrine-project.org/projects/orm/1.2/docs/manual/hierarchical-data/en):

function render_tree_html_list($nodes, Doctrine_Record $current_node, $render = true) {
    $html = '';
    $current_node_level = $current_node->getLevel();
    $counter = 0;
    $found = false;
    $nextSibling = false;

    foreach ($nodes as $i => $node):
        $node_level = $node->getLevel();
        $node_name = $node->getTitulo();
        $node_id = $node->getId();

        if ($current_node !== false) {
            if ($node_level == 0) {

                if ($node->getLft() <= $current_node->getLft() && $node->getRgt() >= $current_node->getRgt()) {
                    // selected root item
                    $root = $node;
                }
            } else if (!isset($root)) {
                // skip all items that are not under the selected root
                continue;
            } else {
                // when selected root is found

                $isInRange = ($root->getLft() <= $node->getLft() && $root->getRgt() >= $node->getRgt());
                if (!$isInRange) {
                    // skip all of the items that are not in range of the selected root
                    continue;
                } else if ($current_node->getLft() && $node->getLft() == $current_node->getLft()) {
                    // selected item reached
                    $found = true;
                    $current_node = $node;
                } else if ($nextSibling !== false && $nextSibling->getLevel() < $node->getLevel()) {

                    // if we have siblings after the selected item
                    // skip any other childerns in the same range or the selected root item
                    continue;
                } else if ($found && $node_level == $node->getLevel()) {
                    // siblings after the selected item
                    $nextSibling = $node;
                }
            }
        } else if ($node_level > 0) {
            // show root items only if no childern is selected
            continue;
        }

        if ($node_level == $current_node_level) {
            if ($counter > 0)
                $html .= '</li>';
        }
        elseif ($node_level > $current_node_level) {
            $html .= '<ol>';
            $current_node_level = $current_node_level + ($node_level - $current_node_level);
        } elseif ($node_level < $current_node_level) {
            $html .= str_repeat('</li></ol>', $current_node_level - $node_level) . '</li>';
            $current_node_level = $current_node_level - ($current_node_level - $node_level);
        }

        $html .= sprintf('<li node="%d" class="%s"><div>%s</div>',
                $node_id,
                (isset($nodes[$i + 1]) && $nodes[$i + 1]->getLevel() > $node_level) ? "node" : "leaf",
                $node->getLevel() > 0 ? link_to($node->getTitulo(), 'cms_categoria_edit', $node) : $node->getTitulo()
        );

        ++$counter;
    endforeach;

    $html .= str_repeat('</li></ol>', $node_level) . '</li>';
    $html = '<ol class="sortable">'. $html .'</ol>';


    return $render ? print($html) : $html;
}

Extra tags: tree, node

Answer 2

As you already managed to sort the sequence, why not just output as needed?

As some leafs need to appear closed, so the iterator should be able to skip children of non-selected nodes.

Doing so lead me to an idea to solve the problem of terminating the output tree (output = parsing). What to do if the last valid node in the sequence is at a higher depth than 0? I appended a NULL terminator for that. So still open levels can be closed before the loop finishes.

Additionally the iterator overloads nodes to offer common methods on them, like comparing against the currently selected element.

The MyRenderTree function (Demo/Full code)

Edit: The Demo Codepad has problems, here is the source-code: Gist Getting nested set model into a but hiding “closed” subtrees

function MyRenderTree($tree = array(array('name'=>'','depth'=>'', 'lft'=>'','rgt'=>'')) , $current=false)
{
    $sequence = new SequenceTreeIterator($tree);

    echo '<ul>';
    $hasChildren = FALSE;
    foreach($sequence as $node)
    {
        if ($close = $sequence->getCloseLevels())
        {
            echo str_repeat('</ul></li>', $close);
            $hasChildren = FALSE;
        }
        if (!$node && $hasChildren)
        {
            echo '</li>', "\n";
        }
        if (!$node) break; # terminator

        $hasChildren = $node->hasChildren();
        $isSelected = $node->isSupersetOf($current);

        $classes = array();
        $isSelected && ($classes[] = 'selected') && $hasChildren && $classes[] = 'open';
        $node->isSame($current) && $classes[] = 'current';

        printf('<li class="%s">%s', implode(' ', $classes), $node['name']);

        if ($hasChildren)
            if ($isSelected)
                echo '<ul>';
            else
                $sequence->skipChildren()
            ;
        else
            echo '</li>'
        ;
    }
    echo '</ul>';
}

This can be solved as well in a single foreach and some variables, however I think for re-useablilty, the implementation based on the SPL Iterators is better.