use abei2017\emoji\Emoji;
Emoji::shortnameToImage('hello:smile:');// hello <img class="emojione" alt="😄" title=":smile:" src="https://cdn.jsdelivr.net/emojione/assets/3.1/png/32/1f604.png">
Emoji::toShort('😄'); // :smile:
Emoji::unicodeToImage('😄'); // <img class="emojione" alt="😄" title=":smile:" src="https://cdn.jsdelivr.net/emojione/assets/3.1/png/32/1f604.png">
Emoji::toImage(':smile:'); // <img class="emojione" alt="😄" title=":smile:" src="https://cdn.jsdelivr.net/emojione/assets/3.1/png/32/1f604.png">
Emoji::shortnameToUnicode(':smile:'); // 😄

// config/web.php
return [
    ...
    'yii2Emoji'=>[
        'emojiSize'=>'32',//32、64、128
    ]
];

// in ActiveRecord
use abei2017\emoji\ValBehavior;
public function behaviors(){
     return [
         'hello'=>[
             'class'=>'abei2017\emoji\ValBehavior',
             'valAttribute'=>'content',// no set, default "content"
             'inFunc'=>'toShort'// no set, default "toShort", and you can set "shortnameToUnicode"
         ]
     ];
 }