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Opened 20 years ago
Closed 20 years ago
#2593 closed defect (bug) (fixed)
The walk_tree family should be a class
| Reported by: | davidhouse | Owned by: | |
|---|---|---|---|
| Priority: | normal | Milestone: | |
| Component: | Administration | Version: | 2.1 |
| Severity: | normal | Keywords: | bg|has-patch |
| Cc: | Focuses: |
Description
Here's a patch that refactors the new walk_tree() functions into a class. Extend the class to create a walker (examples included of categories and pages). Create an instance and call walk() to return the output, then echo or whatever.
Just look at the code :)
Attachments (2)
Change History (8)
#2
@
20 years ago
That was a crap explanation. Lets go again.
walk_tree() is a nice new generic function that got added to be the core a few weeks ago. It's a kind of generic pretty-printer for tree-like structures. For example, we used to have list_cats() and wp_list_pages(), both of which printed a hierarchial structure out (the category list for the former, the page list for the latter). walk_tree() generalises this by allowing you to pass in some callbacks that will get called when starting a new element, finishing an element, or ascending or descending a level.
Callbacks are ugly when abused like this, so this is how my class does it: suppose you want to print some hierarchial tree. Create a new class which extends Walker and defines the following methods:
start_el()end_el()start_lvl()end_lvl()
The names should be fairly self-explanatory. You'll also need to define $dbfields, an associative array:
$dbfields['parent']should be the DB field which is the parent of any given record. This ispost_parentfor posts andcategory_parentfor cats.$dbfields['id']is the same but for the ID. E.g.IDfor posts andcat_IDfor cats.
Once that's done, create an instance and call $instance->walk() passing in the elements you want to print (in object form), and the maximum depth (or -1 to just print flat, no hierarchy). Any extra parameters will get passed to your callbacks.
There are examples in the code.
More stuff should probably be converted to use this, for example:
Might be nice to build some paging into it as well.