Opened 12 years ago
Last modified 5 days ago
#22355 new enhancement
Template stack - Beyond parent/child theme relationships
Reported by: | johnjamesjacoby | Owned by: | |
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Milestone: | Priority: | normal | |
Severity: | normal | Version: | |
Component: | Themes | Keywords: | has-patch |
Focuses: | Cc: |
Description (last modified by )
Problem
Robust plugins (BuddyPress, bbPress, et all) are unable to break out of the parent/child restrictions that WordPress imposes on template output. For these plugins to include their own template parts, elaborate code must be written to hook into several different execution points, requiring an intimate knowledge of the inner workings of WordPress's template loading system.
Solution
Create a stack of template locations, and allow WordPress to transverse this array following the same STYLESHEETPATH/TEMPLATEPATH order it always has, while also enabling additional paths to be added with a priority (similar to the filters API.)
Details
The attached patch includes two new functions in wp-includes/template.php:
- register_template_stack()
- get_template_stack()
Register template stack is a wrapper for the 'template_stack' filter. get_template_stack() is a variation of apply_filters() that returns the array of filtered template locations.
A modification to wp-settings.php calls register_template_stack() two times, passing get_stylesheet_directory() and get_template_directory() as callbacks, to initialize the core parent/child relationship, ensuring complete backwards compatibility.
Result
This allows for plugins to register additional paths in the template loader hierarchy, and enables plugins that may come with their own default template parts the option of registering a fallback template location.
This works with both locate_template() and get_template_part(), and has the added benefit removing duplicate items inside of get_template_stack(), resulting in avoiding an additional file system check should the parent and child themes be the same.
Attachments (6)
Change History (71)
#11
in reply to:
↑ 10
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12 years ago
Replying to scribu:
A usage example from start to finish would be helpful.
Imagine a plugin registers a custom post type 'foo' and wants to bundle templates for twentytwelve support. This plugin would:
- Call: register_theme_stack( 'my_plugin_twentytwelve_template_path', 10 );
- Now, /plugins/my-foo/twentytwelve/single-foo.php is in the stack.
- locate_template() finds a match in the plugin directory.
- Profit.
#12
follow-up:
↓ 16
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12 years ago
And you could control the order (parent theme, child theme, plugin) via the priority arg. Got it.
Instead of:
register_template_stack( 'get_stylesheet_directory', 10 );
why couldn't you do:
register_template_stack( get_stylesheet_directory(), 10 );
since the callback just returns a path, which needs to be computed only once.
#13
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12 years ago
+1 - I've used templates located im plugins several times for a variety of reasons.
#14
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12 years ago
+1 as well. I've built templating systems into plugins as well and this would dramatically cut down the work load.
#16
in reply to:
↑ 12
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12 years ago
Replying to scribu:
why couldn't you do (...) since the callback just returns a path, which needs to be computed only once.
I went the callback route because it came with the filters API; either approach would work.
#20
@
12 years ago
- Cc xoodrew@… added
Pretty neat, and we drop STYLESHEETPATH and TEMPLATEPATH in the process. +1
#21
follow-ups:
↓ 23
↓ 30
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12 years ago
I like this idea.
Is there really a need for the register_template_stack()
wrapper function? I'd prefer to stick with add_filter()
, which is self explanatory.
#23
in reply to:
↑ 21
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12 years ago
Replying to johnbillion:
I like this idea.
Is there really a need for the
register_template_stack()
wrapper function? I'd prefer to stick withadd_filter()
, which is self explanatory.
add_filter() alone would work. The reason to use a dedicated function is to make it API agnostic. Should we want to move it off of the filters API later, we can do so without changing the name of the function or it's parameters.
#30
in reply to:
↑ 21
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12 years ago
Replying to johnbillion:
Is there really a need for the
register_template_stack()
wrapper function? I'd prefer to stick withadd_filter()
, which is self explanatory.
But it isn't a filter. The values of previous function aren't passed to the next function. If I understand correctly, I don't think anything is passed to the function at all.
Right now the filter API is simply a storage mechanism, which doesn't seem right.
@
12 years ago
Patch according to @scribu and @chacha102 suggestions: uses separate global instead of filters api, pass path instead of callback, added 'remove' and 'has' functions
#33
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12 years ago
Above patch uses way of registering locations suggested by @scribu : add_template_stack( get_template_directory(), 12 );
, stop to use filters api as suggested @chacha102 - uses $wp_template_stack
global, and adds functions to remove and check for existence of template location.
#46
follow-up:
↓ 53
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11 years ago
Added a simpler patch that handles this without adding a multitude of extra functions. It also adds a theme_url
function as per #18302, since it makes a lot of sense to introduce that at the same time.
IMO, there no reason we should store this in a global. Doing it there creates a lot of extra code over the simplicity of just filtering an array.
#48
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11 years ago
I'm going to assume we're too late for 3.9 here, but does anyone want to weigh in on the above patch? I'd like to aim for 4.0-early if we're +1 here. nacin seems to like the idea so far, anyone else have thoughts? :)
This ticket was mentioned in IRC in #wordpress-dev by rmccue. View the logs.
10 years ago
#50
@
10 years ago
- Milestone changed from Awaiting Review to 4.1
I really like the idea.
Added an updated patch, where theme_url()
lives with other *_url()
template tags, wp_template_directories()
is get_template_directories()
to reflect the nomenclature in template.php, and some added docs.
I wonder if we should restrict get_template_directories()
to only allow directories to be added after stylesheet and template directories, not before.
#51
follow-up:
↓ 52
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10 years ago
Related: https://core.trac.wordpress.org/attachment/ticket/18302/18302.14.diff -- there's some discussion on that ticket about the desire for the normal inheriting function, but also one where you can specify you want the parent theme url and it to not be overrideable.
#52
in reply to:
↑ 51
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10 years ago
Replying to georgestephanis:
Related: https://core.trac.wordpress.org/attachment/ticket/18302/18302.14.diff -- there's some discussion on that ticket about the desire for the normal inheriting function, but also one where you can specify you want the parent theme url and it to not be overrideable.
I kind of disagree with not having it overridable, but we've also noticed the need to "skip" to the parent. We could possibly add a skip_levels
argument, default to 0, where parent theme is $skip_levels = 1
#53
in reply to:
↑ 46
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10 years ago
Replying to rmccue:
Added a simpler patch that handles this without adding a multitude of extra functions. It also adds a
theme_url
function as per #18302, since it makes a lot of sense to introduce that at the same time.
IMO, there no reason we should store this in a global. Doing it there creates a lot of extra code over the simplicity of just filtering an array.
If all we want is the ability to short-circuit the template loading process with a filter, there are easier ways to do that than this. The extra functions are important for encouraging plugin and theme libraries to announce to the application that they are introducing a new template directory location, to allow other libraries to interact with it accordingly.
Example: both BuddyPress & bbPress are active, and both introduce their own default template locations. A new theme is activated that wants to unhook the default BuddyPress & bbPress default template locations, and completely own the output experience. If BuddyPress & bbPress are forced to register their locations as callbacks, they are much easier to manipulate. Without registering them, plugin and theme authors will need to guess at what each template location is for, and guess at how to interact with it.
Example: both BuddyPress & bbPress are active, again both introducing default template locations. I write a plugin that includes a brand new set of template parts for handling what BuddyPress Member Profiles look like, with an emphasis on forum topics. In my plugin, I should be able to announce a new template location ahead of BuddyPress & bbPress, so my template parts are located first.
In theory, each template and part could be registered (to avoid a whole mess of file_exists()
checks) but that's a lot of additional work for not much gain.
We should try to shy away from function names like get_template_directories()
. The theme/template/stylesheet nomenclature is already messy, and it starts to collide with existing function names like register_theme_directory()
, search_theme_directories()
, etc...
The revised approach in the most recent patches is better than what's in core today, but provides less structure than I originally proposed. I think the _stack
naming conventions proposed in my original patch are more clear, and more accurately represent the complex relationships that plugins have with themes than yet-another-filter at the end of the template funnel.
This ticket was mentioned in Slack in #core by georgestephanis. View the logs.
10 years ago
This ticket was mentioned in Slack in #core by georgestephanis. View the logs.
10 years ago
This ticket was mentioned in Slack in #core by jjj. View the logs.
10 years ago
This ticket was mentioned in Slack in #buddypress by boone. View the logs.
9 years ago
#60
follow-up:
↓ 61
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9 years ago
I'd be happy with a simple filter on the template locations, myself. Patch incoming.
#61
in reply to:
↑ 60
;
follow-up:
↓ 62
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9 years ago
Replying to jfarthing84:
I'd be happy with a simple filter on the template locations, myself.
#62
in reply to:
↑ 61
;
follow-up:
↓ 63
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9 years ago
Replying to johnbillion:
Not the same. That filters the found template, leaving you to still have to search for yours. My proposal placed a filter on the actual locations that are searched, so that you may add locations, similarly to what's proposed in this issue.
#63
in reply to:
↑ 62
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follow-up:
↓ 64
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9 years ago
Replying to jfarthing84:
Not the same. That filters the found template, leaving you to still have to search for yours. My proposal placed a filter on the actual locations that are searched, so that you may add locations, similarly to what's proposed in this issue.
Sorry, wrong ticket number. Should have been #13239.
#64
in reply to:
↑ 63
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9 years ago
Replying to johnbillion:
Sorry, wrong ticket number. Should have been #13239.
Eh, still not quite the same. This issue, along with my patch, focus on filtering the locations that are searched for a template, not the actual template name, like the other issues you've mentioned.
Related: #20509