May
2016

Create a Custom WordPress Plugin

categories: PHP, Wordpress

To start, create a new folder in your “wp-content/plugins” folder called “my-plugin”. Then create a new file within this folder called “myplugin.php” and place this code:

<?php
/*
Plugin Name: my plugin
Plugin URL: http://www.boopathirajan.com
Description: A simple WordPress plugin
Version: 1.0
Author: Boopathi Rajan
Author URI: http://www.boopathirajan.com
*/
?>

If you refresh your administration panel’s plugin page, you’ll now see our plugin listed along with the other ones.Let’s go and activate our plugin by clicking Activate to the right of the plugin entry.

Have any doubt, then comment here!


May
2016

How to add wordpress color picker in custom plugin development

categories: PHP, Wordpress

WordPress has added a color picker in the core code from WordPress v3.5.Plugin developers can now take advantage of this and add a color picker easily in their plugin

How to Add Color Picker

Step 1) Create a java script named as color-script.js and place this code:

jQuery(document).ready(function($){
var myOptions = {
// you can declare a default color here,
// or in the data-default-color attribute on the input
defaultColor: false,
// a callback to fire whenever the color changes to a valid color
change: function(event, ui){},
// a callback to fire when the input is emptied or an invalid color
clear: function() {},
// hide the color picker controls on load
hide: true,
// show a group of common colors beneath the square
// or, supply an array of colors to customize further
palettes: true
};
$('.my-color-field').wpColorPicker(myOptions);
});

Step 2) Enqueue the “wp-color-picker” jquery script


add_action( 'admin_enqueue_scripts', 'mw_enqueue_color_picker' );
function mw_enqueue_color_picker( $hook_suffix ) {
// first check that $hook_suffix is appropriate for your admin page
wp_enqueue_style( 'wp-color-picker' );
wp_enqueue_script( 'my-script-handle', plugins_url('js/color-script.js', __FILE__ ), array( 'wp-color-picker' ), false, true );
}

My plugin now has a color-script.js file that has declared wp-color-picker as a dependency. We can now use the wpColorPicker jQuery method inside it.

Step 3) Add an input (example: text input) to the interface where you want the color picker

<input type="text" value="#abc" class="my-color-field"/>

You can also specify a default color for the field (this will be selected by default):

<input type="text" value="#bada55" data-default-color="#abc" class="my-color-field"/>

That’s it. Your users will now be able to choose a color from the color picker

Have any doubt, then comment here!


May
2016

Add scripts to the wordpress header using custom plugin

categories: PHP, Wordpress

If you would like to add scripts between <head></head> tag then you have to use wp_head() function.for example

Add the following code to your plugin

// Add scripts to wp_head()
function child_theme_head_script() {
    // Your code here
}
add_action( 'wp_head', 'child_theme_head_script' );

That’s it.Code added to wp_head() will be run just before the closing </head> tag.

Have any doubt, then comment here!


May
2016

wordpress admin – create a page without it appearing in the side menu

categories: PHP, Wordpress

Set the parent_slug property to null, example;

add_submenu_page( 
           null,            // -> Set to null - will hide menu link
          'Page Title',    // -> Page Title
          'Menu Title',    // -> Title that would otherwise appear in the menu
          'administrator', // -> Capability level
          'menu_handle',   // -> Still accessible via admin.php?page=menu_handle
          'page_callback' // -> To render the page
    );

This will hide the sub menu page from your parent (top level) menu link.

That’s it. If you have any query then comment here.


May
2016

Add new menu items to wordpress admin by using custom plugin

categories: PHP, Wordpress

To add an menu items to administration menu then you must do three things:

1. create function for building menu

function my_plugin_menu() {
	add_options_page( 'My Plugin Options', 'My Plugin', 'manage_options', 'my-unique-identifier', 'my_plugin_options' );
}

2. Register the above function using the admin_menu action hook.

add_action( 'admin_menu', 'my_plugin_menu' );

3. Create the HTML output for the page displayed when the menu item is clicked 

function my_plugin_options() {
	if ( !current_user_can( 'manage_options' ) )  {
		wp_die( __( 'You do not have sufficient permissions to access this page.' ) );
	}
	echo '<div class="wrap">';
	echo '<p>Here you can put your own HTML code</p>';
	echo '</div>';
}

That’s it. If you have any query then comment here.


May
2016

Create table while activating the custom wordpress plugin

categories: PHP, Wordpress

If you want create a database table while a activating the plugin then you have to register_activation_hook() function. The following code can be placed in your main plugin file. The function will create tables in your Database.


function myplugin_install() {
    global $wpdb; 
    $table_name = $wpdb->prefix . "mytable";
    $db_version = '1.0';
    /**Execute the sql statement to create table**/
    $sql = "CREATE TABLE IF NOT EXISTS " . $table_name . " (
        `ID` int(11) NOT NULL AUTO_INCREMENT,
        `field1` varchar(300) DEFAULT NULL,
		`field2` varchar(300) DEFAULT NULL,
		`field3` varchar(300) DEFAULT NULL,
		`field4` varchar(300) DEFAULT NULL,
		`field5` varchar(300) DEFAULT NULL,
		 PRIMARY KEY (`ID`));"; 
    require_once(ABSPATH . 'wp-admin/includes/upgrade.php');
    dbDelta($sql);
    add_option( "db_version", '1.0' );  
}
// plugin activation hook
register_activation_hook(__FILE__,'myplugin_install');

Then activate your plugin.If already activated then reactivate the plugin. It automatically create table in your database. That’s it.

Have any doubt, then comment here!


May
2016

Show welcome message only once per day

categories: jQuery

If you want to display a welcome message or alert box then you have to add the following JavaScript in your file.

function setCookie(key, value) {
            var expires = new Date();
            expires.setTime(expires.getTime() + (1 * 24 * 60 * 60 * 1000));
            document.cookie = key + '=' + value + ';expires=' + expires.toUTCString();
        }

function getCookie(key) {
           var keyValue = document.cookie.match('(^|;) ?' + key + '=([^;]*)(;|$)');
           return keyValue ? keyValue[2] : null;
        }
if(getCookie('pop')==null)
{
	setCookie('pop',1);
	alert("WELCOME");
}

That’s it. In this code alert box shows only once per day.

Have any doubt, then comment here!


Apr
2016

Difference between wp_insert_user() and wp_create_user()

categories: PHP, Wordpress

There is no difference between wp_insert_user() and wp_create_user(). The entire source of wp_create_user() is given below

function wp_create_user($username, $password, $email = '') {
    $user_login = esc_sql( $username );
    $user_email = esc_sql( $email    );
    $user_pass = $password;

    $userdata = compact('user_login', 'user_email', 'user_pass');
    return wp_insert_user($userdata);
}

It just calls insert version almost immediately, basically a shorthand wrapper.