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.

VueJS Practice #3 – Instance Management

VueJS Practice #3 – Instance Management

Wecome to the third VueJS Practice from German IT Academy. In this module we are going to make sure that we understand the properties and the life cycle of a Vue-Component (or instance).

Problem

Create a Component ProductDetail.vue with

  • a product object with random values for keys (id, price, name)
  • a text input-field “quantity” with default value “0”
  • a text output calculating the total Costs (product price * quantity)

The Component must have following behavior:

  • Before the Component has been mounted, a text output “Specify Quantity.” appears .
  • Data property “quantity” is automatically updated with the input-field quantity.
  • After Quantity has been updated, a text output “Quantity updated.” appears.

Hint

  • For the text above all Content: think about a data property that will be changed on certain Component life cycles.
  • Regarding the quantity and input-field: Do you remember what v-model is good for?
  • For the behavior part: the words “before” and “after” should be ringing a bell in your head. Take a look at the life cycle diagram of VueJS Components/Instances.

Solution

Let’s jump right into the code. Read it and see if you understand everything. If not, see the explanation after the code.

<template>
  <div class="ProductDetail">
      <h2>{{notification}}</h2>
      <p>
        Quantity: <input type="text" v-model="quantity"><br>
        Total Value: {{ totalValue }}$
      </p>
  </div>
</template>

<script>
export default {
  name: 'ProductDetail',

  data() {
    return {
      product: {
        id: 1,
        name: 'VueJS Certificate',
        price: 999
      },
      quantity: 0,
      // You could set 'notification' to desired default value 
      // instead doing it trough life cycle hook 
      notification: '' 
    }
  },

  computed: {
    totalValue: {
      get() {
        return this.quantity*this.product.price
      }
    }
  },

  beforeMount() {
    if(this.quantity==0) {
      this.notification = 'Please specify quantity!'
    }
  },

  updated() {
    if(this.quantity != 0) {
      this.notification = 'Quantity updated!'
    }
  }
}
</script>

<style scoped>
h2 {
  color:orange;
  border: 1px solid orange;
  width:50%;
  margin: 0 25% 0 25%;
}
input {
  height: 40px;
  width: 70px;
  font-size: 25px;
}
.ProductDetail {
  text-align: center;
}

.ProductDetail p {
  font-size: 30px;
}
</style>

Starting with unimportant: styles are just css styles. The {{notification}} in <template> can be either “Please specify quantity” or “Quantity updated!”. The value of this data property changes with the life cycle hooks beforeMount() and updated(). The computed totalValue is an automatic way recalculate a value as soon as a data property (in our case quantity) changes. And then there are the data properties like products with dummy data. The input-field is mapped with quantity data property thanks to v-model.

This is how our result looks like. Simplistic and solves the Task/Problem at hand.

We hope you liked our VueJS Practice and learned something new. If you want to get a deeper insight into how VueJS works, consider enrolling in our VueJS Certificate Junior Course.