Introducing Vue.js

 

Thorsten Lünborg

github.com/linusborg // @linus_borg

whoami

  • Vue core team member since ~06/2016
  • "That guy on the forum" answering your questions 
  • Programming is not my job, but my passion
  • Twitter: @linus_borg
  • Github: @linusborg 

So what's Vue.js?

Vue (pronounced /vjuː/, like view) is a progressive framework for building user interfaces.

 

Vue is focused on the view layer only and it can be used as a library in any project. At the same time, it can be a full-blown framework, perfectly capable of building complex Single Page Applications.

The beginning...

  • Started by Evan You in 2013 as a side project
  • 0.11  November 2014
  • 1.0    Oktober 2015
  • 2.0    Oktober 2016

93,737 GitHub Stars

Top 10 All-Time

2nd most-starred JavaScript framework

 

>20 Core Team members,

many contributors

Today

Let's see some code!

enough marketing...

Vue code is declarative

Opposed to imperative code that we would write with jQuery and similar tools

List Rendering

Imperatively, with jQuery

const items = [
  'thingie',
  'another thingie',
  'lots of stuff',
  'yadda yadda'
];

function listOfStuff() {
  let full_list = '';
  for (let i = 0; i < items.length; i++) {
      full_list = full_list + `<li> ${items[i]} </li>`
  }
  const contain = document.querySelector('#container');
  contain.innerHTML = `<ul> ${full_list} </ul>`;     
}

listOfStuff();

List Rendering

declaratively, with Vue

<div id="app">
  <ul>
    <li v-for="item in items">
      {{ item }}
    </li>
  </ul>
</div>

<script>
new Vue({
  el: '#app',
  data: {
    items: [
      'thingie',
      'another thingie',
      'lots of stuff',
      'yadda yadda'
    ]
  }
});
</script>

Data Binding

<div id="app">
  <h3>Type here:</h3>
  <textarea v-model="message"></textarea><br>
  <p class="booktext">{{ message }} </p>
</div>

<script>
  new Vue({
    el: '#app',
    data() {
      return {
        message: 'This is a good place to type things.'  
      }
    }
  });
</script>

Computed Properties

<div id="app">
  <h3>Type here:</h3>
  <input v-model="firstName"></input><br>
  <input v-model="lastName"></input><br>
  <p class="booktext">{{ fullName }} </p>
</div>

<script>
  new Vue({
    el: '#app',
    data() {
      return {
        firstName: 'Tom',
        lastName: 'Thompson', 
      }
    },
    computed: {
      fullName() {
         return `${this.firstName} ${this.lastName}`
      }
    }
  });
</script>

Conditional Rendering

<div id="app">
  <h3>Type here:</h3>
  <p v-if="showParagraph">
    The visibility of this paragraph can be toggled
    With the button below
  </p>
  <button v-on:click="toggle">
    Toggle
  </button>
</div>

<script>
  new Vue({
    el: '#app',
    data() {
      return {
        showParagraph: true
      }
    },
    methods: {
      toggle() {
         this.showParagraph = !this.showParagraph
      }
    }
  });
</script>

Events & Methods

<div id="app">
  <h3>Type here:</h3>
  <p v-if="showParagraph">
    The visibility of this paragraph can be toggled
    With the button below
  </p>
  <button v-on:click="toggle">
    Toggle
  </button>
</div>

<script>
  new Vue({
    el: '#app',
    data() {
      return {
        showParagraph: true
      }
    },
    methods: {
      toggle() {
         this.showParagraph = !this.showParagraph
      }
    }
  });
</script>

Components

Composing your app with components

<header></header>
<aside>
  <sidebar-item v-for="item in items"></sidebar-item>
</aside>
<main>
  <blogpost v-for="post in posts"></blogpost>
</main>
<footer></footer>
<div id="app">
  <child v-bind:text="message"></child>
</div>

<script>
Vue.component('child', {
  props: ['text'],
  template: `<div>{{ text }}<div>`
});

new Vue({
  el: "#app",
  data() {
    return {
      message: 'hello mr. magoo'
    }
  }
});
</script>

Defining a component

Passing down data with Props

<div id="app">
  <child v-on:clicked="handleClick"></child>
</div>

<script>
Vue.component('child', {
  props: ['text'],
  template: `<button v-on:click="$emit('clicked!')">Click me!</button>`
});

new Vue({
  el: "#app", 
  method: {
    handleClick() {
      // 
    }
  }
});
</script>

Emmitting Events

Props down

 

Events up

<div id="app">
  <child>
    <p>
      This is the 
      <strong>Slot Content</strong>
    </p>
  </child>
</div>

<script>
Vue.component('child', {
  template: `<div> <slot /> <div>`
});

new Vue({
  el: "#app",
});
</script>

Nesting Content with Slots

<!-- Result -->
<div id="app">
  <div class="child">
    <p>
      This is the 
      <strong>Slot Content</strong>
    </p>
  </div>
</div>

"A nice little toy"

"looks a little like angular, yikes!"

"Can I build applications with this?"

Yes we can!

"The Progressive Framework"

  • Routing:                     vue-router
  • State Management: vuex
  • Developer Tooling:  vue-devtools
  • VS Code Plugin         vetur
  • CLI:                             @vue/cli 
  • Bundlers:                  vue-loader
  •                                     rollup/plugin-vue
  • Testing:                      @vue/test-utils

v3 in beta!

v1 in beta!

Single-File Components

(SFCs)

<template>
  <div class="red">{{ text }}<div> 
</template>

<script>
export default {
  props: ['text'],
  methods: {
    // ..
  }
}
</script>

<style>
  .red {
    color: red;
  }
</style>

What's an SFC?

  • File Extension: `.vue`
  • Contains 
    • Markup
    • Code
    • styling
  • Supported by all major bundlers

BUT.....

SEPARATION OF CONCERNS!?!

What many call "seperation of concerns"

 

We call: "Seperation of technologies".

 

Your component is made up of Markup, code, and styling, and you rarely find yourself concerned about only one.

 

So your concern is mostly about all three, they belong together

Demo on codesandbox.io

Questions?

now, or visit me at the forum later:

https://forum.vuejs.org

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