There are a number of ways to achieve what we want, but the best and cleanest method is to exclude using WordPress Action Hook: pre_get_posts. Using this action hook, we can easily exclude any categories in all wordpress generated pages.

Exclude Certain Categories from RSS Feed

First thing you need to do is find the category IDs that you want to hide. WPrecipes explains this pretty well.

Let’s say you want to exclude category 3, 4 and 5. Open your theme’s functions.php, paste these codes:

function mytheme_exclude_cats($query) {
    if ($query->is_feed) {
        $query->set('cat','-3,-4,-5');//seperate by comma
    }
return $query;
}
 
add_action('pre_get_posts','mytheme_exclude_cats');

• pre_get_posts is an action hook that is triggered everytime before wordpress actually retrieve post from database. Therefore, we can tell wordpress to exclude certain categories.
• $query is a wordpress query object that carries information about current query: how many post to show, what categories to show to exclude, at which page does this query runs, etc.
  If you are familiar with writing custom query using WP_Query(), $query is actually the parameters of WP_Query.
• $query->is_feed carries boolean value of TRUE only when you are in Feed Page.

You can run var_dump($query) inside the function to learn more about what the object holds.

Exclude Certain Categories from Homepage

Just simply change “is_feed” to “is_home”:

function mytheme_exclude_cats($query) {
    if ($query->is_home) {
        $query->set('cat','-3,-4,-5');//seperate by comma
    }
return $query;
}
 
add_action('pre_get_posts','mytheme_exclude_cats');

Exclude from other places

Just simply change “is_feed” to the following:

is_feed – in RSS feed page
is_home – in blog homepage
is_category – in category page
is_tag – in tag page
is_search – in search page
is_comment_feed – in comment RSS feed page
is_author – in author archive page

Exclude Specific Categories from more than 1 pages

For example, to exclude category 3, 4 and 5 in both RSS Feed and Search page, it will be just as easy as:

function mytheme_exclude_cats($query) {
    if ($query->is_search || $query->is_feed) {
        $query->set('cat','-3,-4,-5');//seperate by comma
    }
return $query;
}
 
add_action('pre_get_posts','mytheme_exclude_cats');

Hope this helps.

Loading WordPress Engine

First thing to do is to load the WordPress core engine file, wp-load.php. Depends on where you want to put your custom page, you just need to use require_once(‘wp-load.php’), of course point it to correct folder if your custom page is in different folder.

In this example, i put my custom page in my WordPress root folder. Enter this in your custom page:

<?php
 
require_once('wp-load.php');
 
//if you put in "your-wordpress-root/wp-content/" folder , prepend with "../" to go "1 folder up"
//require_once('../wp-load.php');
 
?>

Congratulations, you just created a standalone WordPress custom PHP page. Isn’t that easy?

Making the page Admin-Only

Very often you need limit access to your page to your blog admins only. You can check if the user is an admin after the require_once() statement:

<?php
 
require_once('wp-load.php');
 
if ( !is_user_logged_in() && !current_user_can('manage_options')) {
die('Please login as admin to use this page.');
}
 
//your page content here

As we said previously, after we loaded wp-load.php, we then have access to all WordPress functions, that is why we can use is_user_logged_in() and current_user_can() to check the user.

“manage_options” is the capability we used to check if the user is admin because all admins can “manage_options”. For more capabilities other than just “manage_options”, please refer to the WordPress Codex on Roles & Capabilities.

Hope this helps

As far as I understand, this has nothing to do with FTP settings. This problem occurs because the Apache HTTP service was being run as “nobody” while your Mac user name is a different name. Thus, it has no permission to add/edit your server files so WordPress attempted to use FTP to perform its job.

Editing httpd.conf as Admin

First of all, editing this file is not as easy as using a text editor program and edit it because this read-only file can only be changed by root or superuser, not even administrator. There are 2 or more methods that you use to edit such file:

1. Edit using vi editor in sudo mode using Terminal
2. Run Mac OS TextEditor in sudo mode using Terminal and edit the file

- Terminal is a command line tool just like Window’s CMD.
- Sudo mode refers to running the file as superuser or root.
- Vi editor is a command line editor that is very not user-friendly to use, edit and save (at least for beginner)

Thus we will use Method 2 to perform this task.

1. Run Mac OS TextEditor application in sudo mode using Terminal and edit the file

First of all, open up your Terminal by typing “Terminal” in your Spotlight search box (upper right corner)

Once the terminal is loaded, type this in: (copy and paste if possible)

sudo /Applications/TextEdit.app/Contents/MacOS/TextEdit /Applications/XAMPP/etc/httpd.conf

- sudo command will run the TextEdit application as root
- Seperated by a space after the application path, is the path of httpd.conf (the file to edit)

Press enter, a TextEdit window should pop up and you can then freely edit the file as root.

2. Change the user name and group name

Now, look for these 2 lines:

User nobody
Group admin

Change them to:

User your-mac-username
Group staff

- Staff is the non-admin user group in Mac.
- If you are not sure about your mac username, open Finder > go to Macintosh HD > Users > Look for your folder’s name.

Now restart your XAMPP apache server and it should be working perfectly.

MySQL query that pulls all categories from database

<?php
 
$result = mysql_query("SELECT ".$table_prefix."terms.term_id, ".$table_prefix."terms.name,".$table_prefix."term_taxonomy.taxonomy FROM ".$table_prefix."terms INNER JOIN ".$table_prefix."term_taxonomy ON ".$table_prefix."terms.term_id = ".$table_prefix."term_taxonomy.term_id WHERE ".$table_prefix."term_taxonomy.taxonomy = 'category'");
 
while ($row = mysql_fetch_assoc($result)) {
// uncomment the line below to view the content of $row
// var_dump($row);
 
// category ID = $row['term_id']
// category name = $row['name']
 
echo $row['name'].' - ID '.$row['term_id'].'<br />';
}
 
?>

$table_prefix is a variable declared in wp-config.php, it carries value “wp_” by default unless you changed the setting. It is your SQL tables’ prefix.

WordPress stores all category, tags, etc in wp_term_taxonomy table so we can load all categories name and ID from there.

What about Pages?

<?php
 
$result = mysql_query("SELECT post_title, ID FROM ".$table_prefix."posts WHERE post_type = 'page' AND post_status = 'publish';");
 
while ($row = mysql_fetch_assoc($result)) {
// uncomment the line below to view the content of $row
// var_dump($row);
 
// page ID = $row['ID']
// page name = $row['post_title']
 
echo $row['post_title'].' - ID '.$row['ID'].'<br />';
}
 
?>

WordPress stores all pages in wp_posts table, but with post_type set as “page”.

Hope this helps.

In this guide, we are going to create a simple plugin that scan through the post content for “{donationcode}” and replace it with our paypal donation codes. Jump to complete code

1. Creating a new plugin php file

We created a file called simple_replacer.php and put it into wp-content/plugins/simple_replacer/ folder.

2. The plugin header

<?php
/*
Plugin Name: Simple Replacer
Plugin URI: link to your page to download the plugin or usage guide
Description: Replaces {donationcode} with paypal donation codes
Author: Zen
Version: 1.0
Author URI: http://zenverse.net/
*/
 
?>

3. Adding a function that does the replacing work

Type these codes into the file after the header part (after */)

function the_replacer($content) {
 
$post = str_replace( '{donationcode}' , 'YOUR_DONATION_HTML_CODES' , $content);
 
return $content;
}

NOTE:
Without returning the variable $content, you will ruin the whole post content (return empty content), so make sure you include the “return” line.

4. Adding filter, let wordpress know what we want to do

Add this, 1 line before the php closing tag (?>)

add_filter('the_content', 'the_replacer');
 
//if you want to run the function on excerpts too, uncomment the line below
//add_filter('the_excerpt', 'the_replacer');

NOTE:
The function name “the_replacer” must match the php function that you created in step 3.

The Complete Code

<?php
/*
Plugin Name: Simple Replacer
Plugin URI: link to your page to download the plugin or usage guide
Description: Replaces {donationcode} with paypal donation codes
Author: Zen
Version: 1.0
Author URI: http://zenverse.net/
*/
 
function the_replacer($content) {
 
$post = str_replace( '{donationcode}' , 'YOUR_DONATION_HTML_CODES' , $content);
 
return $content;
}
 
 
add_filter('the_content', 'the_replacer');
 
//if you want to run the function on excerpts too, uncomment the line below
//add_filter('the_excerpt', 'the_replacer');
 
?>

That’s it.

1. Adding codes to The Loop

First of all, if you do not know what is The Loop, please refer to this page.

Open up index.php, look for:

<?php the_excerpt(); ?>

or, your theme may be using this instead of that above:

<?php the_content(); ?>

Add these codes just before the “the_excerpt” or “the_content” line :

<?php if (function_exists('has_post_thumbnail')) {
 if ( has_post_thumbnail() ) { ?>
	<a href="<?php the_permalink(); ?>"><?php the_post_thumbnail( array( 150, 150 ), array( 'class' => 'alignleft') ); ?></a>
<?php } } ?>

Explaination:

• The first line check whether “has_post_thumbnail” function exists before running the code, so that it wouldn’t causes fatal error in older wordpress version.
• has_post_thumbnail is the function that determine whether your post has post thumbnail
• the_post_thumbnail is the function that output the post thumbnail <img> tag

.

2. Using the_post_thumbnail()

According to the wordpress codex, the function’s usage is:

<?php the_post_thumbnail( $size, $attr ); ?>

It can accept 2 arguments. The first argument is the thumbnail size and the second argument is the image’s attributes.

Based on the example in part 1
I used to specify the thumbnail size in array form, like in the above example (a square thumbnail of 150 pixels).

For the second argument, I added .alignleft class to the thumbnail so that it floats left. You can add more attributes like this too:

the_post_thumbnail( array( 150, 150 ), array( 'class' => 'alignleft' , style' => 'border:1px solid red ; margin-right:5px ;' ) );

3. Make your theme support post thumbnail

Open functions.php, scroll to the most bottom and add this before ?> (the closing php tag) :

if ( function_exists( 'add_theme_support' ) ) {
add_theme_support( 'post-thumbnails' );
}

Visit your admin panel and edit/create a post, you will then notice a new box called “Post Thumbnail” appear at the bottom right corner. You can add thumbnail there.

4. I need rectangle thumbnail

When you upload a thumbnail, wordpress generates only square thumbnails. What if you need rectangle thumbnail in your theme?

In your functions.php, look for:

add_theme_support( 'post-thumbnails' );

After that, add this in the next line:

set_post_thumbnail_size( 300, 100, true );

The first argument is width, second is height and the third is crop_flag (if true, wordpress will crop it upon creating the thumbnail, instead of resizing)

From now on, wordpress will generate an additional rectangle thumbnail of size 300 x 100 pixels everytime you upload image.

Okay, you might ask, what about my old uploaded images? I want each of them to have a rectangle thumbnail too. Fortunately, there is a plugin called “Regenerate Thumbnails” which can do the job for you automatically.

Hope this helps

<?php if ( has_post_image() ) { ?>
	<a href="<?php the_permalink(); ?>"><?php the_post_image( array( 125, 125 ), array( 'class' => 'alignleft' ) ); ?></a>
<?php } ?>

However, the function names above were based on wordpress 2.9 RC1. The functions names actually changed when WordPress 2.9 is out.

• has_post_image() -> has_post_thumbnail()
• the_post_image() -> the_post_thumbnail()

So the codes you need to use is:

<?php if ( has_post_thumbnail() ) { ?>
	<a href="<?php the_permalink(); ?>"><?php the_post_thumbnail( array( 125, 125 ), array( 'class' => 'alignleft' ) ); ?></a>
<?php } ?>

That’s it.

New Major Features

• “Trash” feature, if you accidentally delete a post or comment you can bring it back, just like your OS.
• Built-in image editor that allows you to crop, edit, rotate, flip, and scale your images.
• Batch plugin update and compatibility checking which means you can update 10 plugins at once
• Easier video embeds that allow you to just paste a URL on its own line and have it magically turn it into the proper embed code.
• Custom post types so you can juggle more types than just post, page, and attachment.
• Sidebars can now have descriptions so it’s more obvious what and where they do what they do.
• Automatic database optimization support, which you can enable in your wp-config.php file by adding define(‘WP_ALLOW_REPAIR’, true);.
• Rel=canonical support for better SEO. What is rel=”canonical”?
• Themes can register “post thumbnails” which allow them to attach an image to the post.
• When you’re editing files in the theme and plugin editors it remembers your location and takes you back to that line after you save.

More Info & Links

• Video and full list of new features in WordPress 2.9 @ Official Dev Blog
• Download WordPress 2.9

There are 2 functions available :

• wptdb_output()
• wptdb_list_themes()

Function : wptdb_output()

Please read ” Using shortcode ” first to understand this page better.

Description

Allows you to output theme info in template files instead of using shortcode in post. It accepts argument in strings and works exactly like the shortcode . Introduced in version 1.4.

Usage

<?php 
if ( function_exists ( 'wptdb_output' ) ) {
wptdb_output($args);
}
?>

Parameters

theme
(string) The theme’s folder name. Must be set.

format
(string) Format id. Default format will be used if you give an invalid format id.

get
(string) Get single info instead of using format.
Valid values : All available tags

autop
(string) Auto wrap the content with HTML paragraph <p> tag

• true – default
• false / 0 (to display content inline)

echo
(string) Show the result or keep it in a variable. Default is true.

• 1 (true) – default
• 0 (false)

Example of Usage

Display format id of 1

<?php 
if ( function_exists ( 'wptdb_output' ) ) {
wptdb_output( 'theme=my-theme-folder-name&format=1' );
}
?>

Display number of previews (inline)

Lunated theme has <?php 
if ( function_exists ( 'wptdb_output' ) ) {
wptdb_output( 'theme=lunated&get=hits&autop=false' );
}
?> previews in total.

Assign to variable

<?php 
if ( function_exists ( 'wptdb_output' ) ) {
$stored = wptdb_output( 'theme=lunated&get=today&echo=0' );
echo $stored;
}
?>

Argument in array form

<?php 
if ( function_exists ( 'wptdb_output' ) ) {
$stored = wptdb_output( array(
'theme' => 'lunated',
'get' => 'today',
'echo' => '0',
) );
echo $stored;
}
?>

Function : wptdb_list_themes()

Description

Allows you to display a drop-down menu (<select>) for visitors to choose and preview your non-private themes. Introduced in version 1.5

Usage

<?php 
if ( function_exists ( 'wptdb_list_themes' ) ) {
wptdb_list_themes($args);
}
?>

Parameters

style
(string) Type of output. Default is “option” which output <option> to be used with <select>. Valid values:

• option – default

hierarchical
(string) Show parent-child relationship. Default is true. Valid values:

• 1 / true (true) – default
• 0 / false (false)

orderby
(string) Sort themes by wordpress default method or by number of previews. Valid values:

• default – default
• hits

order
(string) Sort order for themes (either ascending or descending). Default is asc. Valid values:

• asc – default
• desc

show_hits
(string) Show number of previews beside theme name in a bracket. Default is false. Valid values:

• true / 1
• false / 0 – default

echo
(string) Show the result or keep it in a variable. Default is true.

• 1 (true) – default
• 0 (false)

Example of Usage

Display drop-down menu using default settings

<?php 
if ( function_exists ( 'wptdb_list_themes' ) ) {
echo '<select name="">';
wptdb_list_themes();
echo '</select>';
}
?>

Display drop-down menu , sort the themes by number of previews in descending order

<?php 
if ( function_exists ( 'wptdb_list_themes' ) ) {
echo '<select name="">';
wptdb_list_themes( 'orderby=hits&order=desc' );
echo '</select>';
}
?>

Display drop-down menu with number of previews shown beside the theme name

<?php 
if ( function_exists ( 'wptdb_list_themes' ) ) {
echo '<select name="">';
wptdb_list_themes( 'show_hits=1' );
echo '</select>';
}
?>

Argument in array form

<?php 
if ( function_exists ( 'wptdb_list_themes' ) ) {
echo '<select name="">';
wptdb_list_themes( array(
'orderby' => 'hits',
'order' => 'desc',
));
echo '</select>';
}
?>

What can you do with shortcode ?

You can display theme info such as number of previews in posts and pages. You can output anything within these supported tags:

• Name of the theme (based on style.css)
• Description of the theme (based on style.css)
• Theme URI (based on style.css)
• Author name (based on style.css)
• Version number of the theme (based on style.css)
• Folder name of the theme
• URL to preview the theme (?themedemo=xxx)
• Total no. of previews
• URL to theme’s screenshot file
• URL to the theme’s info page (if exist)
• URL to the theme’s download page (if exist)
• URL to the page to buy the theme (if exist)

Example of what you can do

Retrieve the number of previews of my Lunated Theme and display it inline

Oh. Lunated theme has been previewed 26675 times in total.

Make a preview link to Lunated theme using default format

Preview Lunated (26675)

Understanding and Using Shortcode

Generally, you need to specify the theme folder name like:

To understand more about the shortcode and examples:

1. Get Single Info only

Use attribute ‘get’ to return only a single infomation

Valid values of attribute ‘get’ :
All tags available are the valid values of attribute ‘get’. However, you can only use one tag at once. (without curly bracket of course)

Example:

• Get number of previews of my Lunated theme and display it inline
  
• Get URL to screenshot file of my Lunated theme and display it inline
  

You can use media button to make the whole process a lot easier.

2. Formatted Output – return output based on format id

use attribute ‘format’

you can create and save a new format at plugin option page

Default format is : <a title="{name} has been previewed {hits} times" href="{demo}">Preview {name} ({hits})</a>

Example:

• Display using default format (you don’t have to specify the format id)
  
• Display using format id 1
  

You can use media button to make the whole process a lot easier.

3. Auto wrap output content with HTML paragraph <p> tag

use attribute ‘autop’

by default autop is set to true, which means it automatically wrap the output content with <p> tags

To display the content inline, use autop=”false”

Example: