number-fieldtype.js

const Fieldtype = {
  mixins: [window.Storyblok.plugin],
  template: `<div><input class="uk-width-1-1" v-model="model.number" /></div>`,
  methods: {
    initWith() {
      return {
        plugin: 'number-plugin',
        number: '0'
      }
    },
    pluginCreated() {
      console.log('plugin:created')
    }
  },
  watch: {
    'model': {
      handler: function (value) {
        value.number = parseInt(value.number, 10)
        if (isNaN(value.number)) {
          value.number = 0
        }
        this.$emit('changed-model', value);
      },
      deep: true
    }
  }
}