Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php  | 
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| 20 | class Give_Email_Notification_Util { | 
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| 21 | /**  | 
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| 22 | * Instance.  | 
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| 23 | *  | 
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| 24 | * @since 2.0  | 
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| 25 | * @access static  | 
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| 26 | * @var  | 
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| 27 | */  | 
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| 28 | static private $instance;  | 
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| 29 | |||
| 30 | /**  | 
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| 31 | * Singleton pattern.  | 
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| 32 | *  | 
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| 33 | * @since 2.0  | 
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| 34 | * @access private  | 
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| 35 | * Give_Email_Notification_Util constructor.  | 
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| 36 | */  | 
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| 37 | 	private function __construct() { | 
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| 39 | |||
| 40 | |||
| 41 | /**  | 
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| 42 | * Get instance.  | 
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| 43 | *  | 
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| 44 | * @since 2.0  | 
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| 45 | * @access static  | 
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| 46 | * @return static  | 
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| 47 | */  | 
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| 48 | 	static function get_instance() { | 
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| 55 | |||
| 56 | |||
| 57 | /**  | 
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| 58 | * Check if notification has preview field or not.  | 
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| 59 | *  | 
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| 60 | * @since 2.0  | 
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| 61 | * @access public  | 
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| 62 | *  | 
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| 63 | * @param Give_Email_Notification $email  | 
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| 64 | *  | 
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| 65 | * @return bool  | 
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| 66 | */  | 
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| 67 | 	public static function has_preview( Give_Email_Notification $email ) { | 
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| 70 | |||
| 71 | /**  | 
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| 72 | * Check if notification has recipient field or not.  | 
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| 73 | *  | 
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| 74 | * @since 2.0  | 
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| 75 | * @access public  | 
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| 76 | *  | 
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| 77 | * @param Give_Email_Notification $email  | 
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| 78 | *  | 
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| 79 | * @return bool  | 
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| 80 | */  | 
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| 81 | 	public static function has_recipient_field( Give_Email_Notification $email ) { | 
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| 84 | |||
| 85 | /**  | 
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| 86 | * Check if admin can edit notification status or not.  | 
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| 87 | *  | 
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| 88 | * @since 2.0  | 
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| 89 | * @access public  | 
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| 90 | *  | 
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| 91 | * @param Give_Email_Notification $email  | 
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| 92 | *  | 
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| 93 | * @return bool  | 
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| 94 | */  | 
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| 95 | 	public static function is_notification_status_editable( Give_Email_Notification $email ) { | 
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| 100 | |||
| 101 | /**  | 
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| 102 | * Check if admin can edit notification status or not.  | 
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| 103 | *  | 
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| 104 | * @since 2.0  | 
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| 105 | * @access public  | 
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| 106 | *  | 
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| 107 | * @param Give_Email_Notification $email  | 
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| 108 | *  | 
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| 109 | * @return bool  | 
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| 110 | */  | 
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| 111 | 	public static function is_content_type_editable( Give_Email_Notification $email ) { | 
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| 114 | |||
| 115 | /**  | 
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| 116 | * Check email preview header active or not.  | 
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| 117 | *  | 
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| 118 | * @since 2.0  | 
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| 119 | * @access public  | 
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| 120 | *  | 
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| 121 | * @param Give_Email_Notification $email  | 
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| 122 | *  | 
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| 123 | * @return bool  | 
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| 124 | */  | 
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| 125 | 	public static function is_email_preview_has_header( Give_Email_Notification $email ) { | 
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| 128 | |||
| 129 | /**  | 
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| 130 | * Check email preview header active or not.  | 
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| 131 | *  | 
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| 132 | * @since 2.0  | 
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| 133 | * @access public  | 
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| 134 | *  | 
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| 135 | * @param Give_Email_Notification $email  | 
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| 136 | *  | 
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| 137 | * @return bool  | 
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| 138 | */  | 
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| 139 | 	public static function is_email_preview( Give_Email_Notification $email ) { | 
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| 142 | |||
| 143 | /**  | 
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| 144 | * Check if email notification setting appear on emails setting page or not.  | 
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| 145 | *  | 
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| 146 | * @since 2.0  | 
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| 147 | * @access public  | 
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| 148 | *  | 
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| 149 | * @param Give_Email_Notification $email  | 
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| 150 | *  | 
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| 151 | * @return bool  | 
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| 152 | */  | 
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| 153 | 	public static function is_show_on_emails_setting_page( Give_Email_Notification $email ){ | 
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| 156 | |||
| 157 | /**  | 
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| 158 | * Check if we can use form email options.  | 
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| 159 | *  | 
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| 160 | * @since 2.0  | 
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| 161 | * @access public  | 
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| 162 | *  | 
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| 163 | * @param Give_Email_Notification $email  | 
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| 164 | * @param int $form_id  | 
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| 165 | *  | 
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| 166 | * @return bool  | 
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| 167 | */  | 
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| 168 | 	public static function can_use_form_email_options( Give_Email_Notification $email, $form_id = null ){ | 
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| 171 | |||
| 172 | /**  | 
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| 173 | * Check email active or not.  | 
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| 174 | *  | 
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| 175 | * @since 2.0  | 
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| 176 | * @access public  | 
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| 177 | *  | 
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| 178 | * @param Give_Email_Notification $email  | 
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| 179 | * @param int $form_id  | 
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| 180 | *  | 
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| 181 | * @return string  | 
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| 182 | */  | 
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| 183 | 	public static function is_email_notification_active( Give_Email_Notification $email, $form_id = null ) { | 
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| 194 | |||
| 195 | /**  | 
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| 196 | * Check if admin preview email or not  | 
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| 197 | *  | 
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| 198 | * @since 2.0  | 
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| 199 | * @access public  | 
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| 200 | * @return bool $is_preview  | 
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| 201 | */  | 
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| 202 | View Code Duplication | 	public static function can_preview_email() { | 
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| 215 | |||
| 216 | /**  | 
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| 217 | * Check if admin preview email or not  | 
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| 218 | *  | 
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| 219 | * @since 2.0  | 
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| 220 | * @access public  | 
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| 221 | * @return bool $is_preview  | 
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| 222 | */  | 
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| 223 | View Code Duplication | 	public static function can_send_preview_email() { | 
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| 236 | |||
| 237 | |||
| 238 | /**  | 
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| 239 | * Get formatted text for email content type.  | 
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| 240 | *  | 
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| 241 | * @since 2.0  | 
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| 242 | * @access public  | 
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| 243 | *  | 
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| 244 | * @param string $content_type  | 
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| 245 | *  | 
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| 246 | * @return string  | 
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| 247 | */  | 
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| 248 | 	public static function get_formatted_email_type( $content_type ) { | 
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| 256 | |||
| 257 | |||
| 258 | /**  | 
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| 259 | * Get email notification option value.  | 
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| 260 | *  | 
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| 261 | * @since 2.0  | 
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| 262 | * @access public  | 
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| 263 | *  | 
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| 264 | * @param Give_Email_Notification $email  | 
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| 265 | * @param string $option_name  | 
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| 266 | * @param int $form_id  | 
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| 267 | * @param mixed $default  | 
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| 268 | *  | 
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| 269 | * @return mixed  | 
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| 270 | */  | 
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| 271 | 	public static function get_value( Give_Email_Notification $email, $option_name, $form_id = null, $default = false ) { | 
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| 307 | }  | 
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| 308 |