Author: latz

My favorite Greasemonkey-Script

Greasemonkey is a fine Firefox-Addon that allows you to execute some Javascript on the page to change the content or do other stuff to enhance the experience.
My all-time favorite is Jasper’s Google Reader subscribe. What does it do?
Every blog, almost every news site, and many other web sites provide RSS feeds. They are a handy thing but some sites make it hard to find the corresponding link or don’t display it at all. The only chance to find the link would be to browse the source code of the page. Scanning the code while you’re in front of a computer? Ridiculous! Let’s use the machine and that’s what this script does.
It looks for links containing the strings “rss”, “atom”, or “rdf” and displays a small icon at the top right of your browser:

If you hover the mouse cursor over the icon all found feeds will be displayed:

As you see not only the main feed is found but also the comment feed and possible others. With this script installed you can simply click on this icon and subscribe to feeds without frantically scanning the page.

The selectbox mystery of WordPress

The other day I wanted to use a selectbox with 5 elements in my plugin’s option page. No problem I thought:

<select size="5">
  <option "test1" />
  <option "test2" />
  <option "test3" />
  <option "test4" />
  <option "test5" />
  <option "test6" />
</select>

What everybody including me expects is something like this:

But I actually got this:

The mystery lies in the style sheet for the admin area:

#wpcontent select {
	padding: 2px;
	height: 2em;
	font-size: 12px;
}

This forces every selectbox to display only one element. I have no idea why this is implemented. There is also a ticket in the WP tracking system discussing this behaviour since two years.

The solution to this problem is quite easy:

<select style="height:auto" size="5">

Seems easy but costed me over 1 hour of my lifetime.

WordPress: Shorten title

A frequently asked question in WordPress forum is how to shorten the title of a post to a predefined number of characters and to append a “…”.

The problem is solved with a few lines of code:

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add_filter( 'the_title', 'short_title' );
function short_title( $title ) {
  $chars = 20;
  if ( strlen( $title ) > $chars ) {
    $title = substr( $title, 0, $chars );
    $title .= " &hellip;";
  }
  return $title;
}

The variable $chars has to be set to the number of characters you want to have in your title and in line 6 you have to define the text to replace the omitted part of the title (&hellip; is the typographically correct version of three points, called ellipse).

It’s a bit disadvantageous that the title could be cut in the middle of a word. If you like you can extend the function accordingly:

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add_filter( 'the_title', 'short_title' );
function short_title( $title ) {
  $chars = 20;
  if ( strlen( $title ) > $chars ) {
    $title = substr( $title, 0, $chars );
    $title = substr($title, 0, strrpos( $title, ' ' ) );		    $title .= " &hellip;";
  }
  return $title;
}

If you copy the function into the file functions.php of your theme all calls of the_title will return the shortened title.

Remove “by author” post section from Genesis themes

As I already wrote in How-to remove the author from your Twenty-Ten posts most blogs do not need the section “by author” since there is only one author.
By default most Genesis themes contain this section (e.g. the prose theme):

Let’s see how-to remove the author’s name from the post info. Continue reading Remove “by author” post section from Genesis themes

WordPress: Remove links from the_category()

The standard way to display the categories a post belongs to is to use the function the_category, e.g, the call the_category(', '); will output:

link, photo, regular, video

As you see the categories are automatically linked to their respective category pages which in most cases is the style needed. Nevertheless there may be situations where you (or your customer) does not want the categories to link anywhere. Unfortunately WordPress does not provide any straightforward method to accomplish this so we have to make a small detour.

There are two ways we can take: rebuild the output or filter the output. Continue reading WordPress: Remove links from the_category()

WordPress plugins: Don’t hard code path names …almost never!

The other day I found a plugin claiming the following in its instructions:

1) Upload the entire my-cool-plugin folder to the /wp-content/plugins/ directory
2) DO NOT change the name of the my-cool-plugin folder
[...]

What the heck? Why shouldn’t I change the name of the folder? The author didn’t actually hard code the plugin path of the plugin, did he? Continue reading WordPress plugins: Don’t hard code path names …almost never!

WordPress: Unified Login Error Messages

If you log-in to your WordPress blog and use an unregistered username the system will answer “ERROR: Invalid username. Lost your password?” and if you got your username right but not your password: “ERROR: The password you entered for the username admin is incorrect. Lost your password?”
So you know independently if you used a registered username or if the password isn’t right. That’s nice of WordPress, isn’t it? From the user point of view sure it is … and from the view of a possible attacker, too! Continue reading WordPress: Unified Login Error Messages

How-to remove the author from your Twenty-Ten posts

There are more than 1300 themes available in the official Theme Directory but many WordPress blogs are using the default theme Twenty Ten. The default header of a post looks like this:

Besides the date of publications the author of the article is displayed but since most blogs are operated by single persons this information is totally unnecessary. Additionally many bloggers write their posting while they’re logged in as Administrator so that the author is displayed has “admin”. This is not only unnecessary but also looks like you can’t handle your blog correctly.
Continue reading How-to remove the author from your Twenty-Ten posts

HTML/PHP: Single and double quotes

If PHP programmers are creating a link from variables often you can see the following code:

echo '<a href="' . $link . '" id="' . $id .'" class="' . $class . '">' . 
       $linktext . '</a>';

or

?>
<a href="<?php echo $link; ?>" id="<?php echo $id; ?>" 
   class="<?php echo $class; ?>"><?php echo $linktext; ?></a>
<?php

or

echo "<a href=\"$link\" id=\"$id\" class=\"$class\">$linktext</a>";

Apart from the personal preferences of the programmer all these snippets have one thing in common: they are hard to read. “Sure!”, you will say, “attributes in HTML have to be enclosed in double quotes and in PHP I have to use one of the above methods.” Are you sure? Do attributes really have to be enclosed in double quotes? The simple answer is: No!
Let’s take a look at the specification:

[…] By default, SGML requires that all attribute values be delimited using either double quotation marks (ASCII decimal 34) or single quotation marks (ASCII decimal 39). Single quote marks can be included within the attribute value when the value is delimited by double quote marks, and vice versa. […]

Double or single quotation marks. That will make things much easier:

echo "<a href='$link' id='$id' class='$class'>$linktext</a>";

As you see the code is much easier to read and that simply happened because you read the specs!

WordPress: Disable plugin table paging

Since WordPress 3.0 the plugin table is paginated by default, 20 entries at a time. In my mind this is totally useless since it means that I have to click through my plugins instead of simply scrolling through them with the mouse wheel. But there’s a more or less “hidden” option to display all plugins at once.
Continue reading WordPress: Disable plugin table paging