vue-contextable

Contextable.js plugin for Vue.js v2. Form validation has never been easier!

This plugin integrates the contextable.js framework into your Vue.js application.

Contextable.js is a simple, unopinionated and minimalist framework for creating context objects with support for unopinionated ORM, object schemas, type casting, validation and error handling. It has a rich API which significantly simplifies server-side and client-side data validation and manipulation. Because it's an unopinionated framework it flawlessly integrates with popular modules like vuex, apollo-client and other related libraries.

Contextable.js together with Vue.js represents a web framework on steroids. Thanks to its powerful context-aware and flexible model objects, a form validation has never been easier. This plugin brings even more elegant way to do form validation using contextable.js and still leaves you freedom to customize and fine-tune the integration.

Make sure you check contextable.js API page for details about the framework.

This is a light weight open source package for Vue.js. The source code is available on GitHub where you can also find our issue tracker.

Related Projects

• Contextable.js: Simple, unopinionated and minimalist framework for creating context objects with support for unopinionated ORM, object schemas, type casting, validation and error handling and more.

Installation

Run the command below to install the package.

$ npm install --save vue-contextable contextable

When used with a module system, you must explicitly install vue-contextable via Vue.use().

import Vue from 'vue';
import VueContextable from 'vue-contextable';
 
Vue.use(VueContextable, {
  reactive: true, // [optional] when `true`, models are watched and validated when a model field is changed
  immediate: false, // [optional] when `true`, all reactively defined models are validated immediately after the component is created,
  debounceTime: 300 // [optional] the number of milliseconds to wait before running model validations
});

Getting Started

Initialize the application context and define a user model.

import {Context, Schema} from 'contextable';
 
const context = new Context(); // context initialization
 
context.defineModel('User', new Schema({ // defining a model
  fields: {
    name: {
      type: 'String',
      validate: [ // field validations
        { // validator recipe
          validator: 'presence', // validator name
          message: 'is required' // validator error message
        }
      ]
    }
  },
  instanceMethods: {
    async $save () { // create new user on the remote server
      try {
        await this.$validate(); // reactively validate
        await fetch('/users', {method: 'POST'}) // send request to the remote server
          .then((r) => r.json()) // read JSON server response
          .then((r) => this.$applyErrors(r.errors)); // load and display possible server errors
        return this.isValid(); // return true if a user has been created
      }
      catch (e) {
        return false; // user has not been created
      }
    }
  }
}));

Attach the context to your Vue.js application.

const app = new Vue({
  context, // injecting context into child components
  ...
});

By passing the context instance to the root Vue instance as the context option, the $context property is injected into every child component.

Form Example

Object validation has been one of the incentives for creating the contextable.js framework. This plugin brings even more elegant way to do form validation using contextable.js.

<template>
  <form novalidate v-on:submit.prevent="submit">
    <!-- input field -->
    <input type="text" v-model="user.name" placeholder="User name"/>
    <span v-if="user.$name.hasErrors()">
      {{ user.$name.errors | firstMessage }}
    </span>
    <!-- buttons -->
    <button v-bind:disabled="user.hasErrors()">Add User</button>
  </form>
</template>
 
<script>
export default {
  contextable: { // contextable namespace
    validate: [ // recipies for defining reactive models
      { // reactive model definition
        dataKey: 'user', // [required] variable name (the name which you would use within the data() block)
        modelName: 'User', // [required] model class name that exists on the application context (defined earlier)
        modelData: {}, // [optional] initial data for pre-populating a model (can also be a function which returns an object)
        reactive: true, // [optional] when `true`, models are watched and validated when a model field is changed
        immediate: false, // [optional] when true, the model is validated immediately when the component is created
        debounceTime: 300 // [optional] the number of milliseconds to wait before running model validations
      }
    ]
  },
  methods: {
    submit () {
      return this.user.$save();
    }
  },
  beforeCreate () {
    // Use the `$populate()` method (e.g. `this.user.$populate({name: 'John'})`) to populate the
    // model (`this.user`) when displaying an edit form. It's a good practice to move this logic
    // into a custom instance or class method within your schema file (as we did for the `submit`
    // method - we created a custom method `$save`).
  }
}
</script> 

Reactive model is an extended instance of a Model class, provided by the contextable.js, on which Vue.js can track changes and re-render when a model field changes. You can access reactive model instances by using the this.{dataKey} syntax (you are actually accessing the data).

You can manually validate the model by calling the this.{dataKey}.$validate() method which is asynchronous and returns a Promise. This is useful when the reactive options is set to false.

Integration

It's natural for contextable.js to be flexible and easily integratable with other technologies. Everything that's added to the context instance is automagically available in every model as this.$context.{my-variable} by default. Vuex, apollo-client and similar technologies represent a common scenario for such integration.

import $store from './store'; // imagine that you've already define the vuex store
import apollo from './apollo'; // imagine that you've already define the vuex store
 
let context = new Context({$store, apollo});
...
let user = new context.User();
user.$context.$store; // => vuex store instance
user.$context.apollo; // => apollo client instance

API

This plugin adds some useful features to contextable.js, which help us write even less code.

Component

By passing the context instance to the root Vue instance as the context option, the $context property is injected into every child component. The plugin also defines the contextable namespace, which can be used for reactive validating of a model.

<script>
export default {
  contextable: { // contextable namespace
    validate: [ // recipies for defining reactive models
      { // reactive model definition
        dataKey: 'user', // [required] variable name (the name which you would use within the data() block)
        modelName: 'User', // [required] model class name that exists on the application context (defined earlier)
        modelData: {}, // [optional] initial data for pre-populating a model (can also be a function which returns an object)
        reactive: true, // [optional] when `true`, models are watched and validated when a model field is changed
        immediate: false, // [optional] when true, the model is validated immediately when the component is created
        debounceTime: 300 // [optional] the number of milliseconds to wait before running model validations
      }
    ]
  },
  methods: {
    getContext () {
      return this.$context; // accessing context instance
    }
  },
  beforeCreate () {
    // Use the `$populate()` method (e.g. `this.user.$populate({name: 'John'})`) to populate the
    // model (`this.user`) when displaying an edit form. It's a good practice to move this logic
    // into a custom instance or class method within your schema file (as we did for the `submit`
    // method - we created a custom method `$save`).
  }
}
</script> 

Model

When a new model is created through the contextable API within a component, some useful reactive methods and variables are applied.

Model.prototype.$applyErrors(errors): Model

A reactive alternative of the applyErrors() method which deeply populates fields with the provided errors (useful for loading validation errors received from the server).

Model.prototype.$build(): Model

Rebuilds model's reactivity system.

export default {
  contextable: {
    validate: [
      {
        dataKey: 'user',
        modelName: 'User'
      }
    ]
  },
  beforeCreate () {
    this.user.book = {title: 'foo'}; // sets field data but the reactivity listeners are removed
    this.user.books = [{title: 'bar'}]; // sets field data but the reactivity listeners are removed
    this.user.$build(); // rebuilds the reactivity system
  }
}

Model.prototype.$populate(data): Model

Reactive alternative of the populate() method which applies data to a model.

export default {
  contextable: {
    validate: [
      {
        dataKey: 'user',
        modelName: 'User'
      }
    ]
  },
  beforeCreate () {
    this.user.$populate({ // sets fields and rebuilds
      name: null,
      book: {},
      books: [{}]
    });
  }
}

Model.prototype.$validate({quiet}): Promise(Model)

Reactive alternative of the validate() method which validates the model fields and throws a validation error if not all fields are valid unless the quiet is set to true.

Example

An example application is available in the ./example folder. You can run the npm run example command to start the server.

Tutorials

See vue-js-cheatsheet for more.

License (MIT)

Copyright (c) 2016 Kristijan Sedlak <xpepermint@gmail.com>

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.