Alessandro Melandri » WordPress

WordPress queries

amelandri — Tue, 09 Mar 2010 10:50:26 +0000

WordPress tip: Get rid of unused post revisions
10+ life saving SQL queries

Some useful WordPress database queries

Selective Javascript Loader 1.1

amelandri — Mon, 14 Sep 2009 09:11:46 +0000

I’ve just update the Selective Javascript Loader plugin with some bugfixes and improvements:

Added the option to choose if Javascript files should be included in the header or in the footer of the page. This option is available only if you are using WordPress 2.8 and above
Added WordPress version checking.
Corrected script inclusion for WordPress 2.7
Some code optimization
Corrected a layout bug in the settings page

Selective Javascript Loader

amelandri — Sun, 13 Sep 2009 17:16:49 +0000

I’ve just released Selective Javascript Loader my first WordPress plugin. It’s a very simple plugin that automatically loads different Javascript files based on the blog section that is being viewed (index, category, single post, page).

It can be really useful if you make extensive use of Javascript in your theme and want to split the code and load functions only when you need them.

Check it out!

Today links

amelandri — Wed, 19 Aug 2009 19:38:57 +0000

WordPress: single post template based on category #2

amelandri — Sun, 09 Aug 2009 09:37:37 +0000

In my previous post I talked about a Lorelle blog post on creating single post templates for different categories.

After using the code snippets “has is” I tryed to build a more flexible solution so I’ve come up with this little function:

function getSingleTemplate(){
 
  $category = get_the_category();
  $templateName = TEMPLATEPATH . '/single_' . $category[0]->category_nicename .'.php';
 
  if (!file_exists($templateName)){
    $templateName = TEMPLATEPATH . '/single_default.php';
  }
  return $templateName;
}

This function must be called inside the single.php template: it gets the first post’s category, searches for a template named like “single_post_first_category_slug.php” and returns its path; if the file doesn’t exists it will return the single_default.php template path.

My single.php template:


$post = $wp_query->post;
include( getSingleTemplate() );
?>

WordPress: single post template based on category

amelandri — Fri, 07 Aug 2009 15:28:06 +0000

Today, while trying to customize the single.php template for a specific category I found a pretty old article written by Lorelle:

Creating Multiple Single Posts for Different Categories.

Her tip is really simple and really useful: just rename your single.php to single1.php and create a new single2.php with your category specific layout; after that, create a new single.php file with this code:


$post = $wp_query->post;
if ( in_category('1') ) {
  include(TEMPLATEPATH . '/single2.php');
} else {
  include(TEMPLATEPATH . '/single1.php');
}
?>

So, if the post is in category 1 WordPress will use the single2.php otherwise it will use single1.php.

Updated

I wrote a more flexible solution: check it out.

Add a category filter to WordPress search form

amelandri — Wed, 05 Aug 2009 07:06:41 +0000

WordPress has a simple function to build a search form for your blog and in this tutorial I’ll show you how to add a category filter to it.

 get_search_form(); ?>

This function will look for a file called searchform.php inside your template folder: if it doesn’t exist it will output the standard search form. So, if it isn’t already in place, create your custom searchform.php and copy into it the default search form output. It should look similar to this:

<form role="search" method="get" id="searchform" action="">
  <div>
    <label class="screen-reader-text" for="s">Search for:</label>
    <input type="text" value="" name="s" id="s" />
    <input type="submit" id="searchsubmit" value="Search" />
  </div>
</form>

We want to add a select box to let the user search in a specific category or in all categories: to achive this we’ll use another default WordPress function.

The wp_dropdown_categories function will build for you a select box with all your categories. Take a look at the documentation for all available options.

( 'show_option_all=All Categories' ); ?>
 

 
<select name='cat' id='cat' class='postform' >
  <option value='0' selected='selected'>All Categories</option>
  <option class="level-0" value="1">Uncategorized</option>
  <option class="level-0" value="3">HTML & CSS</option>
  <option class="level-0" value="4">Java</option>
  <option class="level-0" value="5">Links</option>
  <option class="level-0" value="6">Linux</option>
  <option class="level-0" value="9">Javascript</option>
  <option class="level-0" value="32">XML</option>
</select>

Now add the category select box to the form modifying your searchform.php like this:

<form role="search" method="get" id="searchform" action="">
  <div>
    <label class="screen-reader-text" for="s">Search for:</label>
    <input type="text" value="" name="s" id="s" /> 
    in ( 'show_option_all=All Categories' ); ?> 
    <input type="submit" id="searchsubmit" value="Search" />
  </div>
</form>

That’s it. It just works out of the box.

A finishing touch

Now that you have a nice category filter in your search form it would be great to modify the search result page and add something like Search result for “foo” in category “bar”.
Well, it’s quite easy: we need do add a simple function to the function.php file. Remember that every function in this file will be automatically available in your theme.

This is a simple function that gets the cat parameter from the request and if it’s not null it searches the category name. It has two input parameters so you can pass two strings to be displayed before and after the category name. If cat is null or empty or “0″ (All categories) it will return an empty string.

function getCatSearchFilter($pre,$post){
 
  $category = "";
  $catId = htmlspecialchars($_GET["cat"]);
  if ($catId != null && $catId != '' && $catId != '0'){
    $category = $pre.get_cat_name($catId).$post;
  }
  return $category;
}

Now open you search.php, add the function call to the page and you are done:

<h1>Search Results for (get_search_query());?>(getCatSearchFilter(' in category ',''));?></h1>

WordPress Configuration Tricks

amelandri — Tue, 30 Jun 2009 09:13:27 +0000

Take a look at this post for a list of useful “hidden” configuration settings for your WordPress installation.
I found some nice tricks that I’ve applied to my wp-config.php:

// Number of post revision to keep
define('WP_POST_REVISIONS', 3);
 
// Installation path and template path to reduce database queries
define('WP_HOME', 'http://your_site_url.com');
define('WP_SITEURL', 'http://your_wordpress_directory_url.com');
 
define('TEMPLATEPATH', '/absolute/path/to/wp-content/themes/active-theme');
define('STYLESHEETPATH', '/absolute/path/to/wp-content/themes/active-theme');
 
// Security keys to improve cookies encription
define('AUTH_KEY', 'randomKey');
define('SECURE_AUTH_KEY', 'randomKey');
define('LOGGED_IN_KEY', 'randomKey');
define('NONCE_KEY', 'randomKey');

via Digging Into WordPress.

Custom taxonomies in WordPress 2.8

amelandri — Sat, 20 Jun 2009 09:00:14 +0000

A really good tutorial on building custom taxonomies in WordPress 2.8.

Custom taxonomies in WordPress 2.8

WordPress permalinks best practices

amelandri — Thu, 18 Jun 2009 19:16:35 +0000

Dougal Campbell wrote some interesting notes on permalinks structure and best practices in WordPress. Worth reading:

Efficient permalink strategies for WordPress – Dougal Campbell’s geek ramblings.