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
VueJS Practice – #4 Vuex Store

VueJS Practice – #4 Vuex Store

Here we go again, another VueJS Practice. This time we’ll discuss a very important part of every VueJS Application – the Central Data Store or Vuex Store. Vuex is a VueJS Plugin and extends your Application with centrally available Data and Methods.

Another VueJS Tutorail and Practice by German IT Academy.

Problem / Task

We want to create a Part that is centrally available in our Application: A Shopping Cart. Generate three products in the Vuex Store as states. Create a ProductList.vue View and a ShoppingCart.vue Component. The ProductList.vue should display the products stored in vuex – include a button “Add to Cart”. “Add to Cart” should add the selected Product to a centrally available list, so that the cart list can be access from any other Component. In that view, import ShoppingCart.vue, which should display all Items in the Cart.

Hint

  • For the products: use an Array or Object in Vuex.
  • Displaying multiple UI elements can be done with v-for directive.
  • Centrally available list is nothing else than a list of centrally avaiable products.
  • In order to follow the best practices, consider using
    • Vuex Getters to retrieve data
    • Vuex Actions to modify Vuex States from the outside (e.g. VueComponent)

Solution

As always, let’s jump right into the code.

<template>
  <div class="ShoppingCart">
    <h3>Shopping Cart</h3>
      <p v-for="(item, key) in cart" :key="key">
        {{ products[item].name }}
      </p>
      <hr>
  </div>
</template>

<script>
export default {
  name: 'ShoppingCart',
  computed: {
    products: {
      get() {
        return this.$store.getters['allProducts']
      }
    },
    cart: {
      get() {
        return this.$store.getters['getCartItems']
      }
    }
  }
}
</script>

<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
h3 {
  margin: 40px 0 0;
}
li {
  display: inline-block;
  margin: 0 10px;
}
a {
  color: #42b983;
}
</style>
<template>
  <div class="home">
    <img alt="Vue logo" width="300" src="https://i0.wp.com/code.git-academy.com/wp-content/uploads/2019/10/400dpiLogo.jpg?zoom=1.100000023841858&fit=2077%2C1175&ssl=1">
    <hr>
    <ShoppingCart/>
    <ul>
      <li v-for="product in products" :key="product.id">
        <h1> {{product.name}}</h1>
        <h3> {{product.price}} $</h3>
        <button @click="addToCart(product.id)">Add to Cart</button>
      </li>
    </ul>
  </div>
</template>

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

export default {
  name: 'home',
  components: {
    ShoppingCart
  },
  methods:{
    addToCart(id) {
      this.$store.dispatch('addToCart', id)
    }
  },
  computed: {
    products: {
      get() {
        return this.$store.getters['allProducts']
      }
    }
  }
}
</script>

<style scoped>
li { 
  list-style-type: none;
  margin-bottom: 100px;
}
button {
  background-color: blue;
  color: white;
  font-size: 20px;
  border-radius: 25px;
  border: 1px solid black ;
}
</style>
import Vue from 'vue'
import Vuex from 'vuex'

Vue.use(Vuex)

export default new Vuex.Store({
  state: {
    products: {
      0: {
        id: 0,
        name: 'VueJS T-Shirt black',
        price: 39
      },
      1: {
        id: 1,
        name: 'VueJS T-Shirt white',
        price: 39
      },
      2: {
        id: 2,
        name: 'VueJS T-Shirt blue',
        price: 39
      }
    },
    cart: []
  },
  getters: {
    allProducts(state) {
      return state.products
    },
    getCartItems(state) {
      return state.cart
    }
  },
  mutations: {
    pushCart(state, payload){
      state.cart.push(payload)
    }
  },
  actions: {
    addToCart(context, payload) {
      context.commit('pushCart', payload)
    }
  }
})

Below you can see the visual result of the above code. If you are interested in more VueJS Practice, examples and tutorials, feel free to enroll in our VueJS Course and get certified by German IT Academy.

VueJS Practice

In the store.js we specify out getters. Our products and cart are just lists in the vuex states object. When we press on “Add to Cart”, we initiate a Vuex Action called “Add to Cart” with “this.$store.dispatch(‘addToCart’, id)“. The ShoppingCart.vue simply iterates over the Vuex State Cart and prints out the items.

It’d be better to outsource the v-for loop in ProductList.vue into another Vue-Component ProductItem.vue. ProductList.vue would import ProductItem.vue as a child, and pass a product id. Then, ProductItem.vue could display the product by selecting it via id.