It’s been a busy summer, so I realize posts haven’t been happening much lately.

I’m working on a lot of changes for this site, which will be happening shortly, as well as a few announcements related to some new projects I’m involved in, so stay tuned.

On another note, wordcamp Kelowna is shaping up nicely for September 11th, just a little more than a month away, and I’ll be saying more about that on here too as the time approaches.

Here’s another little function that tends to come in handy. Recently, on a project I did for a client, they had a sidebar where they wanted to display pages that were children of a main page. I whipped up this function to get the ID of a page’s slug and then perform a query:

function get_ID_by_slug($page_slug) {
   $page = get_page_by_path($page_slug);
   if ($page) {
      return $page->ID;
   } else {
      return null;
   }
}

So for example, you could then do a query like this in your sidebar:

$querystr = "SELECT wposts.* FROM $wpdb->posts wposts WHERE wposts.post_parent = '".get_ID_by_slug("white-papers")."' AND wposts.post_status = 'publish' AND wposts.post_type = 'page'";

And you would get all pages that are children of “white-papers”, it’s basic I know, but it works, and has a few other uses than just where I used it.

When I was working on foodjumper, there were times when I wanted to check the parent category, for example, if you’re in the Dinner category or viewing a post in that category, I want to display the proper layout for posts in the Recipes category.

One function that works, is to do a check like this:

function parent_category( $cats, $_post = null ){
     if( is_string($cats) )   $cats = get_cat_ID($cats);
     foreach ( (array) $cats as $cat ) {
          $descendants = get_term_children( (int) $cat, 'category');
          if ( $descendants && in_category( $descendants, $_id ) ) return true;
     }
     return false;
}

WordPress published a similar function on their site, but it used the actual category ID in the function. I found it easier to let you enter the slug instead.

Now, when you want to check if a post is in a category that is a child, you can do a check like this:

<?php
if(in_category('recipes') || parent_category('recipes') ):
     // display this post as a recipe
else:
     // display this post as a normal post
endif;
?>

This can be adapted to almost any type of similar treatment, I just used recipes above as an example since it’s where I just used this function.

Of course, the iPad is a pretty large screen and a fully capable browser, so most websites don’t need to have iPad specific versions of them. But if you need to, you can detect for it with .htaccess

RewriteCond %{HTTP_USER_AGENT} ^.*iPad.*$
RewriteRule ^(.*)$ http://ipad.yourdomain.com [R=301]

This will redirect iPad users to a URL you specify.

On my main wordpress site (this one your reading now), I like to display a single line below each RSS feed item that tells people quickly about some of my other sites.

The ad appears like this:

The code for it is pretty straight forward, and can also be used to display a copyright message linking to your site, or anything along those lines. Place the following code in your theme’s functions.php file:

function insertAds($content) {
  if(is_feed()) {
    srand((float) microtime() * 10000000);
    $banners = array();
    $banners[] = 'Banner number 1. <a href="http://www.somerandomsite/" target="_blank">Some more banner text</a>';
    $banners[] = 'Banner number 2. <a href="http://www.somerandomsite/" target="_blank">Some more banner text</a>';
    $banners[] = 'Banner number 3. <a href="http://www.somerandomsite/" target="_blank">Some more banner text</a>';
    $banners[] = 'Banner number 4. <a href="http://www.somerandomsite/" target="_blank">Some more banner text</a>';
    $rn = array_rand($banners);
    $content = $content.'
<hr />'.$banners[$rn];
  }
  return $content;
}
add_filter('the_excerpt_rss', 'insertAds');
add_filter('the_content', 'insertAds');

You could also replace this with banner images. Anyway, what this does is randomly select which text to display on your rss feed items. So for each article, you could have a different ad appearing.

If you wanted to use this to display only one message (like a copyright), you’d use this version:

function insertMsg($content) {
  if(is_feed()) {
    $banner = 'You are reading my blog. <a href="http://www.linktoblog/" target="_blank">Name of your blog</a>';
    $content = $content.'
<hr />'.$banner;
  }
  return $content;
}
add_filter('the_excerpt_rss', 'insertMsg');
add_filter('the_content', 'insertMsg');

That’s it, like I said, it’s a quick function, but it serves it’s purpose.