You have to do two things to add a new page template to WordPress.

1. Add a file with the correct name

WordPress uses a template hierarchy – you need to give your template the right name. Either page-ID.php – where ID is the post ID of the page you are targeting, or page-SLUG.php – where SLUG is either the slug of the page you are targeting or an understandable name you can assign through the page interface to pages.

2. Add a ‘Template Name’ declaration at the start of your template file

For WordPress to pick your template up, you need to start each page template file with a Template Name string followed by a unique name for the template:

/*
Template Name: Offer page template
*/

You may not like how WordPress’ Categories widget lists categories – particularly if you want to modify the list that’s displayed and hide some categories or have a custom order of categories (rather than alphabetical or by number of posts).

So what’s the easiest way to customise the display of the Categories widget??

You don’t.

Create a new *menu*, add the categories that you want in the order you want them, and add your new menu to the widget area.

So you can go from this:

to this:

This strange thing happened to me earlier today – added a custom post type earlier this week, published an article this afternoon – but then I couldn’t view the published version – WordPress said it couldn’t be found (404 error).

Solution:

Go to your dashboard, and then to settings/permalinks.

Scroll to the bottom and click “Save Changes”. This will force WordPress to update permalink settings and your posts in your custom post type should now work.

I’ve really started to get into using taxonomies in WordPress. One of the early problems I had though was trying to get them to work – so here’s a few things I’ve learned about WordPress taxonomies.

Don’t define taxonomies in functions.php

This is the classic mistake users (and some developers) make. They register (i.e. define) taxonomies in a theme file, change the theme… and wonder where their taxonomies went! (Hint: they’re still there in your database – but if they’re not registered they can’t be accessed.) The solution to this is simple: use a functionality plugin. Then it doesn’t matter which theme you use: as long as the plugin is active, any theme can access your taxonomy data.

Managing taxonomies

WordPress doesn’t have the most robust set of tools for managing taxonomies – you can’t add them via the interface for example, and there are no built in tools for moving things between tags/categories/taxonomies. There are a couple of plugins that I’ve found very helpful:

Term Management Tools

Want to move terms between tags or categories and taxonomies? Want to rename/combine tags? Term Management Tools does that.

TC Custom Taxonomy Filter

You know those helpful dropdown menus you can use to filter posts by category etc.? TC Custom Taxonomy Filter lets you do that for every taxonomy you define. Very useful.

Making taxonomies appear – aka ‘why doesn’t it work’?

So you’ve defined your taxonomy, you’ve added new items/tags, you click on ‘View’ and you get… a 404 page. Go to Settings: Permalinks and select ‘Save Changes’. (NB: you don’t have to make any changes…!) That will update the rewrite rules and your taxonomy should work… assuming of course that you’ve got posts in that taxonomy.

A taxonomy is just a… category

Don’t believe me? Go to a taxonomy template. Add this:

var_dump($wp_query->query_vars);

Categories, tags, taxonomies… all the same thing.

If you were modifying the admin bar in WordPress 3.x you used to call this:

// Add a link to the dashboard in the [pre-existing] site-name node
$wp_admin_bar->add_menu( array(
	'parent' => 'site-name',
	'id'     => 'dashboard',
	'title'  => 'Dashboard',
	'href'   => admin_url(),
) );

to add a new item to your admin toolbar. Now you just replace add_menu with add_node – they have exactly the same effect – and exactly the same syntax – just a slightly different semantic effect on the reader.

If you want to change the heading levels for widgets in a sidebar, you shouldn’t use actions or filters or css to override WordPress: what you do is change how the sidebar is *defined* when it is first initialised.

If your theme uses a sidebar, it has to register it first. Somewhere in your theme (usually in your functions.php file) you will find a call to the register_sidebar( $args ); function, where $args is either a string or an array that defines how the sidebar is structured.

If there are no arguments for the register_sidebar() call then the defaults are used – this is to use h2 for the widget titles. If you want to use a different heading (or none at all) then you need to set the values for 'before_title' and 'after_title' when you call register_sidebar() like this:

<?php register_sidebar(array(
  'name' => __( 'Right Hand Sidebar' ),
  'id' => 'right-sidebar',
  'description' => __( 'Widgets in this area will be shown on the right-hand side.' ),
  'before_title' => '<h1>',
  'after_title' => '</h1>'
));
?>

Not so long ago there was a great little company called Metric Mail that sent you weekly emails that summarised your web traffic data that had been captured by Google Analytics. It was a really useful little service and I recommended it to many people who were just starting web sites and who found the whole process of tracking their web traffic complex and intimidating.

So whatever happened to metricmail? Their website just says ‘We know it’s been quiet lately’ and they’ve not sent out any analyses since June 2012…?