function view::render

Render this view for a certain display.

Note: You should better use just the preview function if you want to render a view.

Parameters

string $display_id: The machine name of the display, which should be rendered.

Return value

(string|NULL) Return the output of the rendered view or NULL if something failed in the process.

File

includes/view.inc, line 998

Class

view

An object to contain all of the data to generate a view, plus the member functions to build the view query, execute the query and render the output.

Code

function render($display_id = NULL) {
    $this->execute($display_id);
    // Check to see if the build failed.
    if (!empty($this->build_info['fail'])) {
        return;
    }
    init_theme();
    $start = views_microtime();
    if (!empty($this->live_preview) && variable_get('views_show_additional_queries', FALSE)) {
        $this->start_query_capture();
    }
    $exposed_form = $this->display_handler
        ->get_plugin('exposed_form');
    $exposed_form->pre_render($this->result);
    // Check for already-cached output.
    if (!empty($this->live_preview)) {
        $cache = FALSE;
    }
    else {
        $cache = $this->display_handler
            ->get_plugin('cache');
    }
    if ($cache && $cache->cache_get('output')) {
        vpr('Used cached output');
    }
    else {
        if ($cache) {
            $cache->cache_start();
        }
        // Run pre_render for the pager as it might change the result.
        if (!empty($this->query->pager)) {
            $this->query->pager
                ->pre_render($this->result);
        }
        // Initialize the style plugin.
        $this->init_style();
        // Give field handlers the opportunity to perform additional queries
        // using the entire resultset prior to rendering.
        if ($this->style_plugin
            ->uses_fields()) {
            foreach ($this->field as $id => $handler) {
                if (!empty($this->field[$id])) {
                    $this->field[$id]
                        ->pre_render($this->result);
                }
            }
        }
        $this->style_plugin
            ->pre_render($this->result);
        // Let modules modify the view just prior to rendering it.
        foreach (module_implements('views_pre_render') as $module) {
            $function = $module . '_views_pre_render';
            $function($this);
        }
        // Let the theme play too, because pre render is a very themey thing.
        $function = $GLOBALS['theme'] . '_views_pre_render';
        if (function_exists($function)) {
            $function($this);
        }
        $this->display_handler->output = $this->display_handler
            ->render();
        if ($cache) {
            $cache->cache_set('output');
        }
    }
    $exposed_form->post_render($this->display_handler->output);
    if ($cache) {
        $cache->post_render($this->display_handler->output);
    }
    // Let modules modify the view output after it is rendered.
    foreach (module_implements('views_post_render') as $module) {
        $function = $module . '_views_post_render';
        $function($this, $this->display_handler->output, $cache);
    }
    // Let the theme play too, because post render is a very themey thing.
    $function = $GLOBALS['theme'] . '_views_post_render';
    if (function_exists($function)) {
        $function($this, $this->display_handler->output, $cache);
    }
    if (!empty($this->live_preview) && variable_get('views_show_additional_queries', FALSE)) {
        $this->end_query_capture();
    }
    $this->render_time = views_microtime() - $start;
    return $this->display_handler->output;
}