Custom Walker initialize error

[ShaneF]

While I was delvoping a customer walker for my wp_list_pages, I was having trouble getting it to read my customer extended class of Walker_Page. I was talking with DD32 last night and he came up with the solution..

wp_list_pages(array('walker' => 'new Walker_Page_Rabbit', 'title_li' => '', 'depth' => '1')); 

...instead of...

wp_list_pages(array('walker' => 'Walker_Page_Rabbit', 'title_li' => '', 'depth' => '1')); 

Clearly the reason for including the "new" was because in the 'category-template.php' and 'post-template.php' had...

 	if ( empty($r['walker']) )
 		$walker = new Walker_Page;
 	else
		$walker = $r['walker'];

I found out that having 'new' in the

$r['walker']

..caused a mismatched argument in the...

return call_user_func_array(array(&$walker, 'walk'), $args);

'new' would be passed on. Once I changed the code in the 'core' to include the new and I would define just 'Walker_Page_Rabbit' in the 'wp_list_page' and it worked perfectly.

 	if ( empty($r['walker']) )
 		$walker = new Walker_Page;
 	else
		$walker = new $r['walker'];

This is a major blocker for any people who are working on customer walkers. Attached is a patch that does work.

[ShaneF]

added Walker_Comment fix

[dd32]

I'm positive that you're not supposed to pass a string to that function to start with.

Example code:

$walker = new Walker_Page_Rabbit();
wp_list_pages(array('walker' => $walker, 'title_li' => '', 'depth' => '1')); 

[ShaneF]

After doing some speed tests.. I can find no fault in this logic.

[ShaneF]

Nevermind. There is an error. I now have this:

$walker_category = new Walker_Category_Rabbit;
		// array('title_li' => '', 'orderby' => 'name', 'show_count' => 1, 'feed' => 'RSS', 'depth' => -1, 'echo' => 0, 'walker' => $walker_category)
		$category_args = array('title_li=&orderby=name&show_count=1&feed=RSS&depth=-1&echo=0&walker='.$walker_category);

and it kills the blog. I am figuring out what is going on.

[dd32]

and it kills the blog. I am figuring out what is going on.

Because its invalid PHP.

for a start: $walker_category = new Walker_Category_Rabbit() - parenthesis on the end.

Secondly, You cannot convert a object to a string and expect it to work - Only use the array format if at all possible, infact, only the array format will work when passing objects.

[filosofo]

Replying to dd32:

Because its invalid PHP.

for a start: $walker_category = new Walker_Category_Rabbit() - parenthesis on the end.

I'm pretty sure parentheses are optional, although I can't find any official documentation that says one way or the other. I've never seen any syntax warnings when omitting them, most PHP books I've read omit them frequently, and even ​this PHP manual example of object instantiation omits them.

However, I'd certainly be interested in seeing any contradicting documentation you can point me to.

[Denis-de-Bernardy]

Replying to filosofo:

However, I'd certainly be interested in seeing any contradicting documentation you can point me to.

parenthesis are optional here, if you don't pass any arguments to the constructor.

[ryan]

If you new the walker before passing it and always use the array format, all is well, yes? That was the intention. Perhaps the phpdoc could be clarified.

[dd32]

I'm pretty sure parentheses are optional

Yep you're right.. Never knew that. Just assumed it since something was fatal erroring that was it..

ryan: perhaps the phpdoc should be clarified for it.. I wish people wouldnt use the string calling methods :P

[westi]

It looks like that wp_list_pages could do with some good phpdoc and then all would be fine.

I think we can move this out to 3.0 and get some documentation written and committed then.

[ShaneF]

Rgr that.

[nacin]

Anyone want to do some inline documentation for this?

[DrewAPicture]

All of the default arguments for wp_list_pages() need documenting at some point, but I'll take just a description for the walker argument here if somebody wants to write one.

[garza]

documentation for wp_list_pages in post-template.php

[garza]

Hi! Added some updated inline documentation for wp_list_pages in post-template.php, thanks to wcatx contributor day!

[DrewAPicture]

Hi garza, thanks for the patch, this is a great start.

Two things:

• Where the arguments are currently listed in quotes, e.g. 'child_of, they should be notated as variables instead: $child_of.
• The purpose of the hash notation is both to spell out what the default arguments mean, as well as to define what the actual default values are. So you also need to list the default at the end of the descriptions, and the values they accept if only certain values are accepted.

Take a look at the PHPDoc block for wp_insert_post​ to see what I mean. Thanks again!

[garza]

Try two for the patch after feedback

[garza]

Attached 11338.1.patch after feedback from DrewAPicture, I tried to use the default description and acceptable values from the codex as much as possible, let me know if it's too much or not consistent.

[DrewAPicture]

In 28357:

Add inline documentation of the default arguments for wp_list_pages().

Props garza for the initial patches.
Fixes #11338.