修改标准WordPress 4.4.2类别小部件以显示自定义分类法

Question

I have edited (a copy of course) /wp-includes/widgets/class-wp-widget-categories.php to force it to show the content of my custom taxonomy by just adding a single line (#59 as for the original file from WP 4.2.2) at the end of $cat_args = array();, so now it reads

$cat_args = array(
        'orderby'      => 'name',
        'show_count'   => $c,
        'hierarchical' => $h,
        'taxonomy'     => 'my_taxonomy'
    );

Nothing really difficult at this point, everything works as intended while the new widget set as list.

Everything ruins immediately after setting the new widget to display as dropdown menu as all items of the the dropdown list point to unexisting URLs.

As my experience level (it is less the zero in fact. but I'm learning!) allows me to see, the problem hides somewhere in line #62 of the original widget

$dropdown_id = ( $first_dropdown ) ? 'cat' : "{$this->id_base}-dropdown-{$this->number}";

as this exact string in my opinion responsible for setting the values for dropdown list items according to the JS that starts at line #82.

I'm able to replace

?cat=

with

my_taxonomy/

at line #88 myself, but I need to put the correct value into $dropdown_id variable.

And this is the problem for me.

Can anybody help?

Answer 1

Question is very unclear. But if you are accessing the custom taxonomies that is categories using this method then it will be not shown. Procedure of displaying custom taxonomies is a lot much different.

Answer 2

As I have discovered the solution myself I'll be the one who will answer my own question, just in case anyone could face the same problem.

It is impossible to force the wp_dropdown_categories() to work with custom taxonomies without making a little modification to the Walker_CategoryDropdown class, due to its ancient bug or feature.

So I need to modify the Walker_CategoryDropdown class found in /wp-includes/class-walker-page-dropdown.php .

To preserve the original class-walker-page-dropdown.php I should copy its content to my plugin file. Then I should replace

$args['value_field'] = 'ID';

found on row 48 with

$args['value_field'] = 'slug';

to make the modified class able to get the taxonomy slug instead of category ID and put it into the <option> 's value=" " term of my new widget.

Then I have deleted rows 1, 47 and 49 and replaced

class Walker_PageDropdown extends Walker {

with

class custom_walker_dropdown extends Walker_CategoryDropdown {

to define this modification as a new separate class.

And finaly I've set the new class as a Walker for wp_dropdown_categories() in my new widget based on WP's native Categories widget.

I have avoided setting the new class widget-wide as it would ruin the List part of the new widget, so the custom_walker_dropdown class should be set as walker only for wp_dropdown_categories() .

The final step is to replace the row 87 of my modified copy of /wp-includes/widgets/class-wp-widget-categories.php

if ( dropdown.options[ dropdown.selectedIndex ].value > 0 ) {

with

if ( dropdown.options[ dropdown.selectedIndex ].value !== 0 ) {

to make the JS responsible for this dropdown menu working.

Bingo! Everything works.

Actually there are tons of custom Walkers found by googling here and there but as for me the best way is to take the original class and make a little modification.