WordPress Plugin Development

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WordPress Plugin Development

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• WordPress is a free CMS (Content Management
  System) and open source blogging tool it has
  totally changed the look on the internet, whether
  we are talking about software or website
  development.
• Now in this part we will be discussing how to
  create a wordpress plugin with our simple but
  effective steps. Now when we talk about plugins,
  then most probably the non tech guys will think
  of a complex function, followed by the knowledge
  of lot of tech languages which is just a myth and
  this is what we will show here, that how easy it
  is to create a Wordpress plugin, all you need to
  know is a bit of PHP and a basic understanding of
  WP file structure and Admin panel.

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• Now before starting up with how to create a WP
  plugin, I would first like to discuss why to
  develop a wordpress plugin.
• Why to have a WordPress plugin?
• In simple words if we want to define plugins,
  then we can say that these are same as addons
  added to your browser for making certain things
  simpler for you.
• Example All in one SEO plugin from Wordpress is
  a plugin that help you in optimizing your site
  and making it search engine friendly with it
  simple but effective features at a single place,
  some of the features provided by. All in one SEO
  plugin are

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• Google Analytics support
• Support for Custom Post Types
• Advanced Canonical URLs
• Fine tune Page Navigational Links
• Built-in API so other plugins/themes can access
  and extend functionality
• ONLY plugin to provide SEO Integration for WP
  e-Commerce sites
• Nonce Security
• this is what a simple Plugin can offer you.
• And developing a pluging will give you a better
  understanding as how things work at the backend
  and another benefit is that being a developer you
  can have a complete control over the function of
  your plugin.

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• Steps of developing a WP plugin

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1. WP Folder Structure

• The wordpress folder structure will show you the
  basic application directory within wordpress, in
  here you will find a Plugin directory where you
  can find all the plugins installed,
• For smaller plug-ins which only requires a single
  .php file, you can place them directly into the
  plug-ins/ directory. But when you start creating
  more complex applications, it is a better option
  to create a sub directory named after your
  plug-in where you can assemble all JavaScript,
  CSS, and HTML along with the PHP functions.

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• Figure 1

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• Figure 2

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• And if you want to provide your plugin to others
  for download, so that others to get benefited
  from it, then these are the simple things that
  you need to keep in mind before providing a
  readme.txt file, this file should contain your
  name and functionality of the plugin and further
  if you want, that people should know about the
  updates in the plugins then you should provide
  details about each revision.

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2. Starting Your PHP File

• Start with a simple PHP file while creating a new
  plugin. This should be your plug-ins official
  name. For example I have created base code and
  have named the file quick-subscribe-now.php.
• The first lines of your plug-in must be comment.
  This is extremely important as WordPress will be
  unable to process your file without it. Below is
  an example code snippit you can copy and mold
  towards your own.

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3. WordPress Naming Conventions And Best
Practices

• While writing code its best to follow
  regulations and guides set up by WordPress. Since
  there are so many functions defined already, you
  can avoid duplicity by providing prefix label to
  all your variables and function names.

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• lt?php  
• function Subscribe_Widget()
• widget_ops array( 'classname' gt
  'subscribe', 'description' gt __('An example
  widget that displays a quick subscribe now
  form.', 'subscribe') )
• control_ops array( 'width' gt 300, 'height'
  gt 350, 'id_base' gt 'subscribe-widget' )
• this-gtWP_Widget( 'subscribe-widget',
  __('Subscribe Widget', 'subscribe'), widget_ops,
  control_ops )
• // the code
•     
• ?gt 
• In the above examples we prefixed all our setting
  names with quick-subscribe-now. This can be
  replaced with any keyword of your choosing
  usually related to your plugin name.

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4. Filters and Actions

• Filters and actions are two completely different
  concepts which relate deeply in the ways they
  manipulate plugin data.
• Understanding Add_filter()
• A filter is used on a bit of text or data being
  passed into WordPress. With filters you are quite
  literally able to filter content through your own
  custom written functions to change data in any
  way.
• Understanding Add_action()
• Actions are similar to filters in that they dont
  work on bits of data but instead target
  pre-defined areas in your templates and admin
  panel.

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• Example you can apply an action whenever you
  update or edit a pages content. A small list of
  example actions
• publish_post  called when a post is published or
  when status is changed into published
• wp_head  called when the template is loaded and
  runs the wp_head() function
• trackback_post  called whenever a new trackback
  is added into a post

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Installing And Running The Plugin

• Ive created a sample file for the plugin to demo
  if youd like to skip the hard coding. Simply
  download this file (rename it to .php) or
  copy/paste the code into a new PHP document and
  upload this to your /wp-content/plugins directory.
  

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• Once completed youll want to access the
  WordPress administration panel and browse your
  current set of plug-ins for the demo just
  installed. Once you activate nothing new will
  happen, not until we manually add in our function
  call. To do this simply navigates Appearance -gt
  Editor and look forsingle.php.
• This file contains the entire template HTML/CSS
  for your basic article post page. Scroll down
  until you find the_content() and replace with the
  example code above. This will limit all your
  article pages to 55 characters no matter what
  view is being used. You could also add in this
  function to similar pages in your templates
  directory such as search.php or archive.php.

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• Thanks You for your valuable time, for more
  information feel free to contact us on
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