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Vue Answers

How to listen to the window scroll event in a Vue.js component?

Sometimes, we want to listen to the window scroll event in a Vue.js component.

In this article, we’ll look at how to listen to the window scroll event in a Vue.js component.

How to listen to the window scroll event in a Vue.js component?

To listen to the window scroll event in a Vue.js component, we can call window.addEventListener.

For instance, we write

export default {
  created() {
    window.addEventListener("scroll", this.handleScroll);
  },
  destroyed() {
    window.removeEventListener("scroll", this.handleScroll);
  },
  methods: {
    handleScroll(event) {
      // ...
    },
  },
};

to call window.addEventListener in the created hook to add the handleScroll method as the callback for the scroll event when the component is loading.

In the destroyed hook, we call window.removeEventListener to remove handleScroll as the scroll event listener when the component unmounts.

Conclusion

To listen to the window scroll event in a Vue.js component, we can call window.addEventListener.

Categories
Vue Answers

How to fix Vue.js unknown custom element error with JavaScript?

Sometimes, we want to fix Vue.js unknown custom element error with JavaScript.

In this article, we’ll look at how to fix Vue.js unknown custom element error with JavaScript.

How to fix Vue.js unknown custom element error with JavaScript?

To fix Vue.js unknown custom element error with JavaScript, we register our component before we use it.

To register it globally, we call Vue.component like

Vue.component("my-task", {
  // ...
});

new Vue({
  // ...
});

We create a register the my-task component with Vue.component.

To register a component locally, we write

export default {
  data() {
    return {};
  },
  components: {
    "my-task": MyTask,
  },
};

to register the my-task component in another component.

We set the my-task tag to render the MyTask component.

Conclusion

To fix Vue.js unknown custom element error with JavaScript, we register our component before we use it.

Categories
Vue Answers

How to go back with Vue Router?

Sometimes, we want to go back with Vue Router.

In this article, we’ll look at how to go back with Vue Router.

How to go back with Vue Router?

To go back with Vue Router, we can use the $router.go method.

For instance, we write

<template>
  <a @click="$router.go(-1)">back</a>
</template>

to add a link that calls $router.go with -1 to go back to the previous route when we click it.

Conclusion

To go back with Vue Router, we can use the $router.go method.

Categories
Vue Answers

How to fire an event when v-model changes with Vue.js?

Sometimes, we want to fire an event when v-model changes with Vue.js.

In this article, we’ll look at how to fire an event when v-model changes with Vue.js.

How to fire an event when v-model changes with Vue.js?

To fire an event when v-model changes with Vue.js, we an listen for the change event.

For instance, we write

<template>
  <input
    type="radio"
    name="optionsRadios"
    id="optionsRadios2"
    value=""
    v-model="srStatus"
    @change="foo"
  />
</template>

to listen for the change event with @change.

If the event is emitted, then we run the foo method.

Conclusion

To fire an event when v-model changes with Vue.js, we an listen for the change event.

Categories
Vue Answers

How to reset a component’s initial data in Vue.js?

Sometimes, we want to reset a component’s initial data in Vue.js.

In this article, we’ll look at how to reset a component’s initial data in Vue.js.

How to reset a component’s initial data in Vue.js?

To reset a component’s initial data in Vue.js, we can create a function that returns the initial state object.

For instance, we write

<script>
const initialState = () => {
  return {
    modalBodyDisplay: "getUserInput",
    submitButtonText: "Lookup",
    addressToConfirm: null,
    bestViewedByTheseBounds: null,
    location: {
      name: null,
      address: null,
      position: null,
    },
  };
};

//...
export default {
  data() {
    return initialState();
  },

  methods: {
    resetWindow() {
      Object.assign(this.$data, initialState());
    },
  },
};
</script>

to call the initialState function in data to return the object returned by initialState as the initial state values.

Then in resetWindow, we call Object.assign(this.$data, initialState()) to overwrite the reactive properties in this.$data with the properties in the object returned by initialState.

Conclusion

To reset a component’s initial data in Vue.js, we can create a function that returns the initial state object.

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