Can you force Vue.js to reload/re-render?

Question

Just a quick question.

Can you force Vue.js to reload/recalculate everything? If so, how?

Answer 1

Try this magic spell:

vm.$forceUpdate();

No need to create any hanging vars :)

Update: I found this solution when I only started working with VueJS. However further exploration proved this approach as a crutch. As far as I recall, in a while I got rid of it simply putting all the properties that failed to refresh automatically (mostly nested ones) into computed properties.

More info here: https://vuejs.org/v2/guide/computed.html

Answer 2

This seems like a pretty clean solution from matthiasg on this issue:

you can also use :key="someVariableUnderYourControl" and change the key when you want to component to be completely rebuilt

For my use case, I was feeding a Vuex getter into a component as a prop. Somehow Vuex would fetch the data but the reactivity wouldn't reliably kick in to rerender the component. In my case, setting the component key to some attribute on the prop guaranteed a refresh when the getters (and the attribute) finally resolved.

Answer 3

Please read this http://michaelnthiessen.com/force-re-render/

The horrible way: reloading the entire page
The terrible way: using the v-if hack
The better way: using Vue’s built-in forceUpdate method
The best way: key-changing on your component

<template>
   <component-to-re-render :key="componentKey" />
</template>

<script>
 export default {
  data() {
    return {
      componentKey: 0,
    };
  },
  methods: {
    forceRerender() {
      this.componentKey += 1;  
    }
  }
 }
</script>

I also use watch: in some situations.

Answer 4

Why?

...do you need to force an update?

Perhaps you are not exploring Vue at its best:

To have Vue automatically react to value changes, the objects must be initially declared in data. Or, if not, they must be added using Vue.set().

See comments in the demo below. Or open the same demo in a JSFiddle here.

new Vue({
  el: '#app',
  data: {
    person: {
      name: 'Edson'
    }
  },
  methods: {
    changeName() {
      // because name is declared in data, whenever it
      // changes, Vue automatically updates
      this.person.name = 'Arantes';
    },
    changeNickname() {
      // because nickname is NOT declared in data, when it
      // changes, Vue will NOT automatically update
      this.person.nickname = 'Pele';
      // although if anything else updates, this change will be seen
    },
    changeNicknameProperly() {
      // when some property is NOT INITIALLY declared in data, the correct way
      // to add it is using Vue.set or this.$set
      Vue.set(this.person, 'address', '123th avenue.');
      
      // subsequent changes can be done directly now and it will auto update
      this.person.address = '345th avenue.';
    }
  }
})

/* CSS just for the demo, it is not necessary at all! */
span:nth-of-type(1),button:nth-of-type(1) { color: blue; }
span:nth-of-type(2),button:nth-of-type(2) { color: red; }
span:nth-of-type(3),button:nth-of-type(3) { color: green; }
span { font-family: monospace }

<script src="https://unpkg.com/vue"></script>

<div id="app">
  <span>person.name: {{ person.name }}</span><br>
  <span>person.nickname: {{ person.nickname }}</span><br>
  <span>person.address: {{ person.address }}</span><br>
  <br>
  <button @click="changeName">this.person.name = 'Arantes'; (will auto update because `name` was in `data`)</button><br>
  <button @click="changeNickname">this.person.nickname = 'Pele'; (will NOT auto update because `nickname` was not in `data`)</button><br>
  <button @click="changeNicknameProperly">Vue.set(this.person, 'address', '99th st.'); (WILL auto update even though `address` was not in `data`)</button>
  <br>
  <br>
  For more info, read the comments in the code. Or check the docs on <b>Reactivity</b> (link below).
</div>

To master this part of Vue, check the Official Docs on Reactivity - Change Detection Caveats. It is a must read!

Answer 5

Try to use this.$router.go(0); to manually reload the current page.

Answer 6

Use vm.$set('varName', value). Look for details into Change_Detection_Caveats.

Answer 7

Sure .. you can simply use the key attribute to force re-render (recreation) at any time.

<mycomponent :key="somevalueunderyourcontrol"></mycomponent>

See https://jsfiddle.net/mgoetzke/epqy1xgf/ for an example

It was also discussed here: https://github.com/vuejs/Discussion/issues/356#issuecomment-336060875

Answer 8

<my-component :key="uniqueKey" />

along with it use this.$set(obj,'obj_key',value) and update uniqueKey for every update in object (obj) value for every update this.uniqueKey++

it worked for me this way

Answer 9

So there's two way you can do this,

1. You can use $forceUpdate() inside your method handler i.e

<your-component @click="reRender()"></your-component>

<script>
export default {
   methods: {
     reRender(){
        this.$forceUpdate()
     }
   }
}
</script>

2. You can give a :key attribute to your component and increment when want to rerender

<your-component :key="index" @click="reRender()"></your-component>

<script>
export default {
   data() {
     return {
        index: 1
     }
   },
   methods: {
     reRender(){
        this.index++
     }
   }
}
</script>

Answer 10

In order to reload/re-render/refresh component, stop the long codings. There is a Vue.JS way of doing that.

Just use :key attribute.

For example:

<my-component :key="unique" />

I am using that one in BS Vue Table Slot. Telling that I will do something for this component so make it unique.

Answer 11

using v-if directive

<div v-if="trulyvalue">
    <component-here />
 </div>

So simply by changing the value of trulyvalue from false to true will cause the component between the div to rerender again

Answer 12

This has worked for me.

created() {
            EventBus.$on('refresh-stores-list', () => {
                this.$forceUpdate();
            });
        },

The other component fires the refresh-stores-list event will cause the current component to rerender

Answer 13

just add this code:

this.$forceUpdate()

GoodLuck

Answer 14

I found a way. It's a bit hacky but works.

vm.$set("x",0);
vm.$delete("x");

Where vm is your view-model object, and x is a non-existent variable.

Vue.js will complain about this in the console log but it does trigger a refresh for all data. Tested with version 1.0.26.

Answer 15

Worked for me

    data () {
        return {
            userInfo: null,
            offers: null
        }
    },

    watch: {
        '$route'() {
            this.userInfo = null
            this.offers = null
            this.loadUserInfo()
            this.getUserOffers()
        }
    }

Answer 16

<router-view :key="$route.params.slug" />

just use key with your any params its auto reload children..

Answer 17

I had this issue with an image gallery that I wanted to rerender due to changes made on a different tab. So tab1 = imageGallery, tab2 = favoriteImages

tab @change="updateGallery()" -> this forces my v-for directive to process the filteredImages function every time I switch tabs.

<script>
export default {
  data() {
    return {
      currentTab: 0,
      tab: null,
      colorFilter: "",
      colors: ["None", "Beige", "Black"], 
      items: ["Image Gallery", "Favorite Images"]
    };
  },
  methods: {
    filteredImages: function() {
      return this.$store.getters.getImageDatabase.filter(img => {
        if (img.color.match(this.colorFilter)) return true;
      });
    },
    updateGallery: async function() {
      // instance is responsive to changes
      // change is made and forces filteredImages to do its thing
      // async await forces the browser to slow down and allows changes to take effect
      await this.$nextTick(function() {
        this.colorFilter = "Black";
      });

      await this.$nextTick(function() {
        // Doesnt hurt to zero out filters on change
        this.colorFilter = "";
      });
    }
  }
};
</script>

Answer 18

sorry guys, except page reload method(flickering), none of them works for me (:key didn't worked).

and i found this method from old vue.js forum which is works for me:

https://github.com/vuejs/Discussion/issues/356

<template>
    <div v-if="show">
       <button @click="rerender">re-render</button>
    </div>
</template>
<script>
    export default {
        data(){
            return {show:true}
        },
        methods:{
            rerender(){
                this.show = false
                this.$nextTick(() => {
                    this.show = true
                    console.log('re-render start')
                    this.$nextTick(() => {
                        console.log('re-render end')
                    })
                })
            }
        }
    }
</script>

Answer 19

The approach of adding :key to the vue-router lib's router-view component cause's fickers for me, so I went vue-router's 'in-component guard' to intercept updates and refresh the entire page accordingly when there's an update of the path on the same route (as $router.go, $router.push, $router.replace weren't any help). The only caveat with this is that we're for a second breaking the singe-page app behavior, by refreshing the page.

  beforeRouteUpdate(to, from, next) {
    if (to.path !== from.path) {
      window.location = to.path;
    }
  },