VueJS Tutorial – #6 Template Syntax

VueJS Tutorial – #6 Template Syntax

Before we start with another VueJS Tutorial, let me promote our VueJS Course with a Certificate right at the beginning. You’ll see more interactive and deeper Content about VueJS. At the end you’ll also receive a VueJS Certificate from German IT Academy. That’s it.

Problem / Task

While coding a solution for the following tasks, make sure to make use of every single v-directive at least once: v-text, v-html, v-once and v-model. Also, do not forget to use conditional and iterative v-directives, if needed.

  • Create a new Vue Component CustomizeDonut.vue
  • Use following JSON Sample data as ‘donuts‘ data property
  • In CustomizeDonut, create 4-step input process, in which a user has to perform one data-selection in each step. Use v-model as much as you can. The steps should have individual h1 titles and individual Button Values.
    • Select Donut by name (see Sample Data)
    • Select Batter Type
    • Select Topping Type
    • Last step: Show the summary and a dummy button “Order Donut”

Hint

Here is a sample Object of a Donut. Few things stand out: We have a type and a name. We have a list of “batters” and “topping”, which contain object with further details.

	{
		"id": "0001",
		"type": "donut",
		"name": "Cake",
		"ppu": 0.55,
		"batters":
			{
				"batter":
					[
						{ "id": "1001", "type": "Regular" },
						{ "id": "1002", "type": "Chocolate" },
						{ "id": "1003", "type": "Blueberry" },
						{ "id": "1004", "type": "Devil's Food" }
					]
			},
		"topping":
			[
				{ "id": "5001", "type": "None" },
				{ "id": "5002", "type": "Glazed" },
				{ "id": "5005", "type": "Sugar" },
				{ "id": "5007", "type": "Powdered Sugar" },
				{ "id": "5006", "type": "Chocolate with Sprinkles" },
				{ "id": "5003", "type": "Chocolate" },
				{ "id": "5004", "type": "Maple" }
			]
	}
  • To have a multi-step process, you have to track the status of the current process. You can do it with an object. Or simpler yet, a variable that will store the step number that the user is currently performing.

Solution

Here is the solution we came up with for this VueJS Tutorial. Please that is no definite solution, except that the v-directive are used correctly. We smashed the solution into one Vue Component, that way we make it simpler to understand by not having the code in 3-4 different files.

<template>
  <div id="CustomizeDonut">
    <h1 v-text="stepConfig[step].title"></h1>
      <div v-if="step == 1">
            <select v-model="userInput.donutId">
                <option v-for="donut in donuts" :value="donut.id" :key="donut.id" v-text="donut.name"/>
            </select>
      </div>
      <div v-else-if="step == 2">
            <select v-model="userInput.batterId">
                <option v-for="batter in batters" :value="batter.id" :key="batter.id" v-text="batter.type"/>
            </select>
      </div>
      <div v-else-if="step == 3">
            <select v-model="userInput.toppingId">
                <option v-for="topping in toppings" :value="topping.id" :key="topping.id" v-text="topping.type"/>
            </select>
      </div>
      <div v-else-if="step == 4">
            Donut Id: {{userInput.donutId}}<br>
            Batter Id: {{userInput.batterId}}<br>
            Topping Id: {{userInput.toppingId}}<br>
      </div>
      <button @click="stepConfig[step].nextStep" v-text="stepConfig[step].button"/>
  </div>
</template>

<script>
    export default {
        name: "CustomizeDonut",
        data() {
            return {
                donuts: [{
                        "id": "0001",
                        "type": "donut",
                        "name": "Cake",
                        "ppu": 0.55,
                        "batters": {
                            "batter": [{
                                    "id": "1001",
                                    "type": "Regular"
                                },
                                {
                                    "id": "1002",
                                    "type": "Chocolate"
                                },
                                {
                                    "id": "1003",
                                    "type": "Blueberry"
                                },
                                {
                                    "id": "1004",
                                    "type": "Devil's Food"
                                }
                            ]
                        },
                        "topping": [{
                                "id": "5001",
                                "type": "None"
                            },
                            {
                                "id": "5002",
                                "type": "Glazed"
                            },
                            {
                                "id": "5005",
                                "type": "Sugar"
                            },
                            {
                                "id": "5007",
                                "type": "Powdered Sugar"
                            },
                            {
                                "id": "5006",
                                "type": "Chocolate with Sprinkles"
                            },
                            {
                                "id": "5003",
                                "type": "Chocolate"
                            },
                            {
                                "id": "5004",
                                "type": "Maple"
                            }
                        ]
                    },
                    {
                        "id": "0002",
                        "type": "donut",
                        "name": "Raised",
                        "ppu": 0.55,
                        "batters": {
                            "batter": [{
                                "id": "1001",
                                "type": "Regular"
                            }]
                        },
                        "topping": [{
                                "id": "5001",
                                "type": "None"
                            },
                            {
                                "id": "5002",
                                "type": "Glazed"
                            },
                            {
                                "id": "5005",
                                "type": "Sugar"
                            },
                            {
                                "id": "5003",
                                "type": "Chocolate"
                            },
                            {
                                "id": "5004",
                                "type": "Maple"
                            }
                        ]
                    },
                    {
                        "id": "0003",
                        "type": "donut",
                        "name": "Old Fashioned",
                        "ppu": 0.55,
                        "batters": {
                            "batter": [{
                                    "id": "1001",
                                    "type": "Regular"
                                },
                                {
                                    "id": "1002",
                                    "type": "Chocolate"
                                }
                            ]
                        },
                        "topping": [{
                                "id": "5001",
                                "type": "None"
                            },
                            {
                                "id": "5002",
                                "type": "Glazed"
                            },
                            {
                                "id": "5003",
                                "type": "Chocolate"
                            },
                            {
                                "id": "5004",
                                "type": "Maple"
                            }
                        ]
                    }
                ],
                step: 1, // We start with step 1
                stepConfig: {
                    1: {
                        title: "Donut Type",
                        button: `Go to Step 2`,
                        nextStep: () => {this.step = 2;}
                    },
                    2: {
                        title: "Batter Type",
                        button: `Go to Step 3`,
                        nextStep: () => {this.step = 3;}
                    },
                    3: {
                        title: "Topping Type",
                        button: `Final Step`,
                        nextStep: () => {this.step = 4;}
                    },
                    4: {
                        title: "Your Donut",
                        button: `Send order and Start over`,
                        nextStep: () => {this.step = 1;}
                    },
                },
                userInput: {
                    donutId: 0,
                    batterId: 0,
                    toppingId: 0
                }
            }
        },
        computed: {
            batters: {
                get() {
                    const currentDonut = this.donuts.filter(item => item.id == this.userInput.donutId)
                    return currentDonut[0].batters.batter
                }
            },
            toppings: {
                get() {
                    const currentDonut = this.donuts.filter(item => item.id == this.userInput.donutId)
                    return currentDonut[0].topping
                }
            }
        }
    }
</script>

<style>
button, option, select {
    margin: 20px 20px 20px 20px;
    font-size: 30px;
    color: rgb(255, 255, 255);
    background: rgba(255, 106, 0, 0.972)
}
</style>

Here is quite a lot happening, let’s go trough it.

First we have created a very simple step process by having a step data property and showing conditional HTML content based on that property; we achieve this with v-if and v-else-if v-directives.

Our data property stepConfig tells our App what title, what button text and what the button-action should be. Notice that we use a function for stepConfig.nextStep; this is because we use the v-directive v-on on our button. This directive needs a function as a parameter. @click=”stepConfig[step].nextStep”

Our computed properties help us extract or filter the correct batters and topping for the donut selected by the user.

In order to store user Input we created an object userInput and we mapped the keys “userInput.donutId”, “userInput.batterId” and “userInput.toppingId” with v-model to the select.options HTML Tags. This way our App has always the most recent user input saved in this Object.

If you want to learn more about VueJS and become a VueJS Certified Developer, please take a look at our VueJS Course + Certificate.

Here is a visual version of our solution. Please note, we know VueJS, but we suck at Design.

VueJS Tutorial- #5 Component Relationships

VueJS Tutorial- #5 Component Relationships

Welcome to another VueJS Tutorial. Let’s explore a very important topic in VueJS: the relationship between your Vue-Components. It’s crucial because everything is importing everything from everywhere anytime…or something like this.

For those who are new to VueJS Tutorial / VueJS Practice: we create a fictional problem / task for you to solve. To go through it and try and code a solution that would solve the issue. Then you compare it with the solution provided by German IT Academy.

Problem / Task

We need

  • create DataSourceList.vue that reads from state ‘datasources’ in vuex store.
  • For every Entry in the ‘datasources’ list, embed a a DataSourceItem.vue in the DataSourceList.vue.
  • DataSourceItem Component receives the props ‘id’ from the Parent. With that id the Child fetches all the data from ‘datasources’ in vuex store and displays them.
  • DataSourceItem Component receives a slot from the Parent and displays the content in a random place.

Hint

  • When importing a Vue-Component, do not forget to also import it inside the Parent Instance
  • As reminder, props are those data values that you pass to a child as a HTML Tag Attribute (:propName=data) and slot is the data between the HTML Opening and Closing tag.
  • To create Vuex Getter that receives a parameter from the outside, read: https://vuex.vuejs.org/guide/getters.html

You can learn more about VueJS with our VueJS Course and get VueJS certified.

Solution

Source code:

import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

export default new Vuex.Store({
  state: {
    datasources: [
      {
        id:0,
        name:'Google Cloud Storage',
        interface: 'REST API',
        activated: true
      },
      {
        id:1,
        name:'AWS S3 Bucket',
        interface: 'REST API',
        activated: true
      },
      {
        id:2,
        name:'On-Deman Server Storage',
        interface: 'SSH',
        activated: false
      }
    ]
  },
  getters: {
    getAllDataSources(state) {
      return state.datasources
    },
    getDataSourceById: (state) => (id) => {
      for (let i = 0; i < state.datasources.length; i++) {
        if (state.datasources[i].id == id) {
          return state.datasources[i]
        }
      }
    }
  },
  mutations: {
  },
  actions: {
  }
})

We have the list as a state variable. We have to getters: one for every DataSource and one getter that will return only the Entry with the specified id.

<template>
  <div class="DataSourceItem">
    <h2 :style="activated()"> 
      {{this.datasource.name}}
    </h2>
    <h3> {{datasource.interface}}</h3>
  </div>
</template>

<script>
export default {
  name: 'DataSourceItem',
  props: {
    id: Number
  },
  computed: {
    datasource: {
      get(){
        return this.$store.getters.getDataSourceById(this.id)
      }
    }
  },
  methods: {
    activated() {
      if (this.datasource.activated) {
        return 'background-color:green;'
      }
      return 'background-color:red;'
    }
  }
}
</script>

<style scoped>
h3 {
  margin: 40px 0 0;
}
ul {
  list-style-type: none;
  padding: 0;
}
li {
  display: inline-block;
  margin: 0 10px;
}
a {
  color: #42b983;
}
</style>

The DataSourceItem.vue receives the id as a props. With that id the Component will retrieve the DataSource from Vuex Store. It’ll use the Vuex getter that we’ll define below.

<template>
  <div class="home">
    <img 
      alt="German IT Academy"
      width="200"
      src="https://i0.wp.com/code.git-academy.com/wp-content/uploads/2019/10/400dpiLogo.jpg?zoom=1.100000023841858&fit=2077%2C1175&ssl=1">
    <div v-for="datasource in datasources" :key="datasource.id">  
      <DataSourceItem :id="datasource.id"/>
    </div>
  </div>
</template>

<script>
// @ is an alias to /src
import DataSourceItem from '@/components/DataSourceItem.vue'

export default {
  name: 'DataSourceList',
  components: {
    DataSourceItem
  },
  computed: {
    datasources: {
      get(){
        return this.$store.getters['getAllDataSources']
      }
    },
  }
}
</script>

German IT Academy hopes you learned something new with this VueJS Tutorial. You can learn more about VueJS with our VueJS Course and get VueJS certified.

The visual version of the solution looks like this.

VueJS Course and VueJS Certificate