Get/set v-model value inside an Vue directive

vue-directive-get-set-v-model.js

//+ Jonas Raoni Soares Silva
//@ http://raoni.org

// NOTES:
// 1. The vnode is provided by the directive callbacks
// 2. If eval sounds scary to you, you might replace it by any function that provides "navigation" from a string like "array[0].property" (that's what you get from the "expression") =]

getValue (vnode) {
  //standard v-model
  if (vnode.data.model) {
    return vnode.data.model.value;
  }
  //component with custom v-model...
  return eval(`vnode.context.$data.${vnode.data.directives.find(directive => directive.name === 'model').expression}`);
}

setValue (vnode, value) {
  //standard v-model
  if (vnode.data.model) {
    return vnode.data.model.callback(value);
  }
  //component with custom v-model
  return eval(`vnode.context.$data.${vnode.data.directives.find(directive => directive.name === 'model').expression} = value`);
}