//1
jQuery(‘.something’).each( function(){
jQuery(this).addClass( ‘stuff’ );
});
jQuery.data( document.body, ‘foo’, 1337 );
 
// jQuery noConflict wrapper:
(function($) {
// $() will work here
$(‘.something’).each( function(){
$(this).addClass( ‘stuff’ );
});
$.data( document.body, ‘foo’, 1337 );
})(jQuery);

<?php
/*
Plugin Name: Ajax Read More
Plugin URI: http://example.com/
Description: Ajaxify the "Read more" links
Version: 1.0
*/
 
// Flag to state if the script is needed
global $ssd_arm_needjs;
$ssd_arm_needjs = false;
 
// Plugin version, bump it up if you update the plugin
define( 'ssd_ARM_VERSION', '1.0' );
 
// Enqueue the script, in the footer
add_action( 'template_redirect', 'ssd_arm_add_js' );
function ssd_arm_add_js() {
 
    // Enqueue the script
    wp_enqueue_script( 'ssd_arm',
        plugin_dir_url( __FILE__ ).'js/script.js',
        array('jquery'), ssd_ARM_VERSION, true
    );
 
    // Get current page protocol
    $protocol = isset( $_SERVER["HTTPS"]) ? 'https://' : 'http://';
 
    // Output admin-ajax.php URL with same protocol as current page
    $params = array(
      'ajaxurl' => admin_url( 'admin-ajax.php', $protocol )
    );
    wp_localize_script( 'ssd_arm', 'ssd_arm', $params );
}
 
// Don't add the script if actually not needed
add_action( 'wp_print_footer_scripts', 'ssd_arm_footer_maybe_remove', 1 );
function ssd_arm_footer_maybe_remove() {
    global $ssd_arm_needjs;
    if( !$ssd_arm_needjs ) {
        wp_deregister_script( 'ssd_arm' );
    }
}
 
// Inspect each post to check if there's a "read more" tag
add_action( 'the_post', 'ssd_arm_check_readmore' );
function ssd_arm_check_readmore( $post ) {
    if ( preg_match('/<!--more(.*?)?-->/', $post->post_content )
    && !is_single() ) {
        global $ssd_arm_needjs; 
        $ssd_arm_needjs = true;
    }
}
 
// Ajax handler
add_action('wp_ajax_nopriv_ssd_arm_ajax', 'ssd_arm_ajax');
add_action('wp_ajax_ssd_arm_ajax', 'ssd_arm_ajax');
function ssd_arm_ajax() {
    // Modify the way WP gets post content
    add_filter( 'the_content', 'ssd_arm_get_2nd_half' );
 
    // setup Query
    query_posts( 'p='.absint( $_REQUEST['post_id'] ) );
 
    // "The Loop"
    if ( have_posts() ) : while ( have_posts() ) : the_post();
        the_content();
    endwhile; else:
        echo "post not found :/";
    endif;
 
    // reset Query
    wp_reset_query();
    die();
}
 
// Get second part of a post after the "more" jump
function ssd_arm_get_2nd_half( $content ) {
    $id = absint( $_REQUEST['post_id'] );
    $content = preg_replace( "!^.*<span id=\"more-$id\"></span>!s", '', $content );
    return $content;
}
 
 
//JS code
if( typeof(console) == 'object' ) {
    console.log( 'script loaded' );
}
 
(function($) {
    $('.more-link').click(function(){
        var link = this;
        $(link).html('loading...');
        // href="' . get_permalink() . "#more-{$post->ID}"
        var post_id = $(link).attr('href').replace(/^.*#more-/, '');
        var data = {
            action: 'ssd_arm_ajax',
            post_id: post_id
        };
        $.get(ssd_arm.ajaxurl, data, function(data){
            $(link).after(data).remove();
        });
        return false;
    });
})(jQuery);

<?php
/*
Plugin Name: Add JavaScript
Plugin URI: http://example.com/
Description: Demonstrates how to properly insert JS into different pages
*/
 
// URL to the /js directory of the plugin
define( 'ssd_INSERTJS', plugin_dir_url( __FILE__).'js' );
 
// Add new admin pages
add_action('admin_menu', 'ssd_insertjs_add_page');
function ssd_insertjs_add_page() {
    // Add JS to all the admin pages
    wp_enqueue_script( 'ssd_insertjs_1', ssd_INSERTJS.'/script.js.php?where=admin' );
 
    // Add a page under Settings
    $settings = add_options_page( 'Insert JS', 'Insert JS', 'manage_options',
        'ssd_insertjs_settings', 'ssd_insertjs_options_page'
    );
 
    // Add JS to the setting page
    add_action( 'load-'.$settings, 'ssd_insertjs_add_settings_script' );
 
    // Add a page under Users
    $users = add_users_page( 'Insert JS', 'Insert JS', 'manage_options',
        'ssd_insertjs_users', 'ssd_insertjs_users_page'
    );
 
    // Add JS to the users page, with a different hook
    add_action( 'admin_print_scripts-'.$users, 'ssd_insertjs_add_users_script' );
}
 
// Add JS to the plugin's settings page
function ssd_insertjs_add_settings_script() {
    wp_enqueue_script( 'ssd_insertjs_2', ssd_INSERTJS.'/script.js.php?where=settings' );
}
 
// Add JS to the plugin's users page, in the page footer
function ssd_insertjs_add_users_script() {
    wp_enqueue_script( 'ssd_insertjs_3', ssd_INSERTJS.'/script.js.php?where=users',
        '', '', true
    );
}
 
// Add JS to the Comments page
add_action( 'load-edit-comments.php', 'ssd_insertjs_on_comments' );
function ssd_insertjs_on_comments() {
    wp_enqueue_script( 'ssd_insertjs_4', ssd_INSERTJS.'/script.js.php?where=comments' );
}
 
 
// Add JS to pages of the blog
add_action( 'template_redirect', 'ssd_insertjs_add_scripts_blog' );
function ssd_insertjs_add_scripts_blog() {
    // To all pages of the blog
    wp_enqueue_script( 'ssd_insertjs_5', ssd_INSERTJS.'/script.js.php?where=blog' );
 
    // To single post pages
    if( is_single() ) {
        wp_enqueue_script( 'ssd_insertjs_6', ssd_INSERTJS.'/script.js.php?where=single' );
    }
 
    // To the "About" page
    if( is_page('About') ) {
        wp_enqueue_script( 'ssd_insertjs_7', ssd_INSERTJS.'/script.js.php?where=about' );
    }
}
 
 
// Draw options page
function ssd_insertjs_options_page() {
    ?>
    <div class="wrap">
    <?php screen_icon(); ?>
    <h2>Insert JavaScript</h2>
 
    <?php
    var_dump( plugin_basename( dirname(__FILE__) ) );
    var_dump( plugin_dir_url( __FILE__) );
    ?>
 
    <p>This sample plugin selectively adds different JS to the following pages:</p>
    <ol>
        <li>Admin part:
        <ol>
            <li>This very page</li>
            <li>This plugin page under the Users menu</li>
            <li>The Comments page</li>
        </ol></li>
        <li>Blog part:
        <ol>
            <li>All blog pages</li>
            <li>Single post pages</li>
        </ol></li>
    </ol>
    </div>
    <?php
}
 
// Draw users page
function ssd_insertjs_users_page() {
    ?>
    <div class="wrap">
    <?php screen_icon(); ?>
    <h2>Insert JavaScript</h2>
    <p>This is another sample page. Here, the JS is added in the footer (view page source).</p>
    </div>
    <?php
}
 
//code JS
<?php
// Send proper header for the browser
header('Content-type: application/javascript');
 
// Get context to display appropriate notice
$page = isset( $_GET['where'] ) ? $_GET['where'] : '' ;
 
switch( $page ) {
    // admin pages:
    case 'admin':
        $context = "all admin pages";
        break;
 
    case 'settings':
        $context = "plugin settings page";
        break;
 
    case 'users':
        $context = "plugin users page";
        break;
 
    case 'comments':
        $context = "comments page";
        break;
 
    // public pages:
    case 'single':
        $context = "blog single pages";
        break;
 
    case 'about':
        $context = "About page";
        break;
 
    case 'blog':
        $context = "all blog pages";
        break;
}
 
?>
 
// Now javascript part, here a simple alert
alert( 'This script should only load in: <?php echo $context; ?>' );

<?php
/*
Plugin Name: Instant Delete Comment
Plugin URI: http://example.com/
Description: Add a quick link to instantly delete comments
*/
 
// Add script on single post & pages with comments only, if user has edit rights
add_action( 'template_redirect', 'ssd_idc_addjs_ifcomments' );
function ssd_idc_addjs_ifcomments() {
    if( is_single() && current_user_can( 'moderate_comments' ) ) {
        global $post;
        if( $post->comment_count ) {
            $path = plugin_dir_url( __FILE__ );
 
            wp_enqueue_script( 'ssd_idc', $path.'js/script.js' );
            $protocol = isset( $_SERVER["HTTPS"]) ? 'https://' : 'http://';
            $params = array(
              'ajaxurl' => admin_url( 'admin-ajax.php', $protocol )
            );
            wp_localize_script( 'ssd_idc', 'ssd_idc', $params );
        }
    }
}
 
// Add an admin link to each comment
add_filter( 'comment_text', 'ssd_idc_add_link' );
function ssd_idc_add_link( $text ) {
    // Get current comment ID
    global $comment;
    $comment_id = $comment->comment_ID;
 
    // Get link to admin page to trash comment, and add nonces to it
    $link = admin_url( 'comment.php?action=trash&c='.$comment_id );
    $link = wp_nonce_url( $link, 'ssd_idc-delete-'.$comment_id );
    $link = "<a href='$link' class='ssd_idc_link'>delete comment</a>";
 
    // Append link to comment text
    return $text."<p>[admin: $link]</p>";
}
 
// Ajax handler
add_action( 'wp_ajax_ssd_idc_ajax_delete', 'ssd_idc_ajax_delete' );
function ssd_idc_ajax_delete() {
    $cid = absint( $_POST['cid'] );
 
    $response = new WP_Ajax_Response;
 
    if(
        current_user_can( 'moderate_comments' ) &&
        check_ajax_referer( 'ssd_idc-delete-'.$cid, 'nonce', false ) &&
        wp_delete_comment( $cid  )
    ) {
        // Request successful
        $response->add( array(
            'data' => 'success',
            'supplemental' => array(
                'cid'     => $cid,
                'message' => 'this comment has been deleted'
            ),
        ) );
    } else {
        // Request failed
        $response->add( array(
            'data' => 'error',
            'supplemental' => array(
                'cid'     => $cid,
                'message' => 'an error occured'
            ),
        ) );
    }
 
    $response->send();
 
    exit();
}
 
//code JS - script.js
jQuery(document).ready(function($) {
 
    $('.ssd_idc_link').click(function(){
        var link = this;
        // get comment id and nonce
        var href = $(link).attr( 'href' );
        var id =    href.replace(/^.*c=(\d+).*$/, '$1');
        var nonce = href.replace(/^.*_wpnonce=([a-z0-9]+).*$/, '$1');
 
        var data = {
            action: 'ssd_idc_ajax_delete',
            cid: id,
            nonce: nonce
        }
 
        $.post( ssd_idc.ajaxurl, data, function(data){
            var status  = $(data).find('response_data').text();
            var message = $(data).find('supplemental message').text();
            if( status == 'success' ) {
                $(link).parent().after( '<p><b>'+message+'</b></p>' ).remove();
            } else {
                alert( message );
            }
        });
 
        return false;
 
    });
 
});