Joomla 3菜单活动状态不起作用

Question

I have a problem with joomla 3.

I make menu using the custom template is located in the /templates/mytemplate/html/mod_menu/mainmenu.php

But when I go on any link in the menu, then the array index of "active" is always false.

For example, curent page is http://localhost/about.html

and in the array "active" index is empty

[1] => stdClass Object
        (
            [id] => 102
            [menutype] => mainmenu
            [title] => О проекте
            [alias] => about
            [note] => 
            [route] => about
            [link] => index.php?option=com_content&view=article&id=1
            [type] => component
            [level] => 1
            [language] => *
            [browserNav] => 0
            [access] => 1
            [params] => JRegistry Object
                (
                    [data:protected] => stdClass Object
                        (
                            [show_title] => 
                            [link_titles] => 
                            [show_intro] => 
                            [info_block_position] => 
                            [show_category] => 
                            [link_category] => 
                            [show_parent_category] => 
                            [link_parent_category] => 
                            [show_author] => 
                            [link_author] => 
                            [show_create_date] => 
                            [show_modify_date] => 
                            [show_publish_date] => 
                            [show_item_navigation] => 
                            [show_vote] => 
                            [show_tags] => 
                            [show_icons] => 
                            [show_print_icon] => 
                            [show_email_icon] => 
                            [show_hits] => 
                            [show_noauth] => 
                            [urls_position] => 
                            [menu-anchor_title] => 
                            [menu-anchor_css] => 
                            [menu_image] => 
                            [menu_text] => 1
                            [page_title] => 
                            [show_page_heading] => 0
                            [page_heading] => 
                            [pageclass_sfx] => 
                            [menu-meta_description] => 
                            [menu-meta_keywords] => 
                            [robots] => 
                            [secure] => 0
                        )

                )

            [home] => 0
            [img] => 
            [template_style_id] => 0
            [component_id] => 22
            [parent_id] => 1
            [component] => com_content
            [tree] => Array
                (
                    [0] => 102
                )

            [query] => Array
                (
                    [option] => com_content
                    [view] => article
                    [id] => 1
                )

            [deeper] => 
            [shallower] => 
            [level_diff] => 0
            [parent] => 
this empty  [active] =>
            [flink] => /about.html
            [anchor_css] => 
            [anchor_title] => 
            [menu_image] => 
        )

Answer 1

From the looks of the base mod_menu files, the active property is always set to false by the helper that loads the menu and instead they use their own checks to see what is active. Namely, the base mod_menu.php file sets these values:

$list       = ModMenuHelper::getList($params);
$base       = ModMenuHelper::getBase($params);
$active     = ModMenuHelper::getActive($params);
$active_id  = $active->id;
$path       = $base->tree;

So active_id will contain the id of the current menu item. Thus if you want the current menu you can check like this:

foreach ($list as $i => &$item) :
if ($item->id == $active_id) {
        // do something with active item
    }
    ....
}

$list is set by the main file, so that is accessible in your layout file.

You can also check for parent items above the active item in the same foreach loop with this check:

if (in_array($item->id, $path)) {}

Technically you could run the first foreach loop and set $item->active to true if you wanted. However, at that point you probably could just have done what you wanted with the item!