vue-material/src/components/mdInputContainer/mdTextarea.vue

<template>
  <textarea
    class="md-input"
    :value="value"
    :disabled="disabled"
    :required="required"
    :placeholder="placeholder"
    :maxlength="maxlength"
    @focus="onFocus"
    @blur="onBlur"
    @input="onInput"></textarea>
</template>

<script>
  import autosize from 'autosize';
  import common from './common';
  import getClosestVueParent from '../../core/utils/getClosestVueParent';

  export default {
    mixins: [common],
    watch: {
      value() {
        this.$nextTick(() => {
          autosize.update(this.$el);
        });
      }
    },
    mounted() {
      this.parentContainer = getClosestVueParent(this.$parent, 'md-input-container');

      if (!this.parentContainer) {
        this.$destroy();

        throw new Error('You should wrap the md-textarea in a md-input-container');
      }

      this.setParentDisabled();
      this.setParentRequired();
      this.setParentPlaceholder();
      this.setParentValue();
      this.handleMaxLength();

      if (!this.$el.getAttribute('rows')) {
        this.$el.setAttribute('rows', '1');
      }

      autosize(this.$el);
    },
    beforeDestroy() {
      autosize.destroy(this.$el);
    }
  };
</script>