Knowledge Base

get_nodes()

Description

Get all nodes from database for a specific metadata field or parent.

Use $parent = NULL and recursive = TRUE to get all nodes for a category tree field

Use $offset and $rows only when returning a subset.

IMPORTANT: this should be used only with category trees
IMPORTANT! For non-fixed list fields this is capped at 10000
to avoid out of memory errors

Parameters

Column	Type	Default	Description
$resource_type_field	integer		ID of the metadata field
$parent	integer	null	ID of parent node
$recursive	boolean	false	Set to true to get children nodes as well.
$offset	integer	null	Specifies the offset of the first row to return
$rows	integer	null	Specifies the maximum number of rows to return.
$name	string	''	Filter by name of node
$use_count	boolean	false	Show how many resources use a particular node in the node properties
$order_by_translated_name	boolean	false	Flag to order by translated names rather then the order_by column

Return

array

Location

include/node_functions.php lines 289 to 401

Definition

 
function get_nodes($resource_type_field, $parent = null, $recursive = false, $offset = null, $rows = null, $name = '', 
    $use_count = false, $order_by_translated_name = false)
    {
    global $FIXED_LIST_FIELD_TYPES;
    debug_function_call("get_nodes", func_get_args());

    if(!is_int_loose( $resource_type_field))
        {
        return [];    
        }
        
    if(!is_null($parent))
        {
        if ($parent == ""){$parent=null;}
        else {$parent = (int) $parent;}
        }

    $fieldinfo  = get_resource_type_field($resource_type_field);
    if($fieldinfo === false){return false;}
    if(!in_array($fieldinfo["type"],$FIXED_LIST_FIELD_TYPES) && (is_null($rows) || (int)$rows > 10000 ))
        {
        $rows = 10000;
        }

    $return_nodes = array();

    $parameters= [];
    $sql = "";
    add_sql_node_language($sql,$parameters);

    $parameters[] = "i";$parameters[] = $resource_type_field;

    // Filter by name if required
    $filter_by_name = '';
    if('' != $name)
        {
        $filter_by_name = " AND `name` LIKE ?";
        $parameters[]="s";$parameters[]="%" . $name . "%";
        }

    // Option to include a usage count alongside each node
    $use_count_sql="";
    if($use_count)
        {
        $use_count_sql = ",(SELECT count(resource) FROM resource_node WHERE resource_node.resource > 0 AND resource_node.node = node.ref) AS use_count";
        }  

    $parent_sql = is_null($parent) ? ($recursive ? "TRUE" : "parent IS NULL") : ("parent = ?");
    if (strpos($parent_sql,"?")!==false) {$parameters[]="i";$parameters[]=$parent;}
    
    // Order by translated_name or order_by based on flag
    $order_by = $order_by_translated_name ? "translated_name" : "order_by";

    // Check if limiting is required
    $limit = '';
    if(!is_null($offset) && is_int($offset)) # Offset specified
        {
        if(!is_null($rows) && is_int($rows)) # Row limit specified
            {
            $limit = "LIMIT ?,?";
            $parameters[]="i";$parameters[]=$offset;
            $parameters[]="i";$parameters[]=$rows;
            }
        else # Row limit absent
            {
            $limit = "LIMIT ?,999999999"; # Use a large arbitrary limit
            $parameters[]="i";$parameters[]=$offset;
            }
        }
    else # Offset not specified
        {
        if(!is_null($rows) && is_int($rows)) # Row limit specified
            {
            $limit = "LIMIT ?";
            $parameters[]="i";$parameters[]=$rows;
            }
        }
        
    $query = "SELECT " . columns_in("node") . $sql . $use_count_sql . "
        FROM node 
        WHERE resource_type_field = ?
        " . $filter_by_name . "
        AND " . $parent_sql . "
        ORDER BY " . $order_by . ", ref ASC
        " . $limit;

    $sqlcache = in_array($fieldinfo["type"],$FIXED_LIST_FIELD_TYPES) ? "schema" : "";
    $nodes = ps_query($query,$parameters,$sqlcache);
  
    // No need to recurse if no parent was specified as we already have all nodes
    if($recursive && (int)$parent > 0)
        {
        foreach($nodes as $node)
            {
            foreach(get_nodes($resource_type_field, $node['ref'], true) as $sub_node)
                {
                array_push($nodes, $sub_node);
                }
            }
        }
    else
        {
        $return_nodes = $nodes;
        }

    if($recursive)
        {
        // Need to reorder so that parents are ordered by first, with children between (query will have returned them all according to the passed order_by)
        $return_nodes = order_tree_nodes($return_nodes);
        }
   
    return $return_nodes;
    }


This article was last updated 18th April 2024 09:35 Europe/London time based on the source file dated 15th April 2024 11:30 Europe/London time.