div contenteditable

.input{
            width:100%;
            height:auto;
            min-height: 24px;
            font-size:14px;
            padding:5px 8px;
            border:1px solid #ddd;
            word-break: break-all;
}
.input:empty::before {
            content: attr(placeholder);
}

<div class='input form-control' contenteditable placeholder='请输入文字' ng-bind="input" ng-model="input"></div>