Understanding how to use the 'this' variable in Vue components is essential for efficiently modifying DOM elements. Let's dive into a clarification on the usage of 'this'

Within my vue component, the structure is as follows:


export default{
  name: '',
  data: function () {
    return {
      var1 :{},
      var2 : {},
      ...
    }
  },
  created: function () {
      this.methodName1()
  },
  methods: {
    methodName2: function () {
       var context = this

       rp(options).then(function () {
          context.methodName1()
          return null
       }).catch(function (err) {
          console.log(err)
       })
    },
    methodName1: function () {
         //function body
    }
  }
}

I'm puzzled about why this.methodName1 returns undefined whereas


var context = this; 
context.methodName1

functions correctly inside the methodName2?

What is the reason for needing to reference the this variable specifically when manipulating DOM elements?

Answer №1

Take a close look at the Lifecycle-Diagram provided in the official documentation. It appears that you are attempting to execute this.methodName1() within the created hook, which occurs before your methods have been initialized.
The proper place to access all your methods is within the mounted lifecycle hook.
Modify your code from:

created: function () {
     this.methodName1()
},

to

mounted: function () {
     this.methodName1()
},

Once you make this adjustment, everything should work as expected.

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