Issue that the asynchronous request data is not updated in Vue
In development, asynchronous requests are a common requirement to fetch data from the backend and update component state. However, developers may experience issues with data not being updated after the asynchronous request is completed, which may affect the user experience and the accuracy of the data.
1. Common reasons why asynchronous request data is not updated
Status update is not triggered correctly
In Vue, status updates need to be triggered through Vue's responsive system.
If you directly modify the index of the object's properties or array, Vue cannot detect these changes, resulting in the data not being updated.
Example:
[index] = newValue; // Vue cannot detect direct modification of array index = newValue; // Vue Unable to detect dynamic properties of an object
Asynchronous request is not handled correctly
After the asynchronous request is completed, the status may not be updated correctly, or the logic of the status update is not triggered correctly.
Example:
async fetchData() {
const response = await fetch('/api/data');
const data = await ();
= data; // Status update is not triggered correctly}Component not rendering correctly
If the component is not rendered correctly, even if the status is updated, the latest data may not be visible.
This may be caused by a component's lifecycle or conditional rendering logic error.
Caching issues
Browser cache or HTTP cache may cause the request to return old data, resulting in the data not being updated.
Concurrent request issues
In concurrent requests, multiple asynchronous operations may interfere with each other, resulting in data not being correctly updated.
2. Solution
Ensure that status updates trigger Vue's responsive system
Using the provided by Vueorthis.$setMethod to update an array or object to ensure that the status update is detected by Vue.
Example:
this.$set(, index, newValue); // Update the arraythis.$set(, 'newProperty', newValue); // Update Objects
Correctly handle asynchronous requests
Ensure that the status is updated correctly after the asynchronous request is completed and provides error handling logic when the request fails.
Example:
async fetchData() {
try {
const response = await fetch('/api/data');
const data = await ();
= data; // Make sure the status is updated } catch (error) {
('Failed to fetch data:', error);
}
}Optimize component rendering logic
Ensure that the life cycle and conditional rendering logic of the component are correct, and avoid data not being updated due to rendering problems.
Example:
<template>
<div v-if="data">
{{ data }}
</div>
</template>
<script>
export default {
data() {
return {
data: null
};
},
async mounted() {
await ();
},
methods: {
async fetchData() {
const response = await fetch('/api/data');
const data = await ();
= data;
}
}
};
</script>Handle caching issues
Add timestamps or random parameters to the request to avoid browser caching issues.
Example:
async fetchData() {
const response = await fetch(`/api/data?timestamp=${()}`);
const data = await ();
= data;
}Resolve concurrent request issues
In concurrent requests, useorasync/awaitMake sure the requests are completed in order and the status is updated correctly.
Example:
async fetchData() {
const [data1, data2] = await ([
fetch('/api/data1').then(response => ()),
fetch('/api/data2').then(response => ())
]);
this.data1 = data1;
this.data2 = data2;
}3. Best practice suggestions
Simplify asynchronous logic with async/await
async/awaitSyntax simplifies the processing logic of asynchronous requests and makes the code easier to read.
Use error handling mechanism
Add error handling logic in asynchronous requests to ensure user-friendly prompts are provided when requests fail.
Use vue-axios or other encapsulation tools
usevue-axiosOr other encapsulation tools can simplify processing of HTTP requests and better integrate into Vue's responsive systems.
Avoid direct operation of DOM
After the asynchronous request is completed, avoid direct manipulation of the DOM, but update the view through Vue's data binding.
Summarize
Problems in Vue where asynchronous request data are not updated are usually caused by the state update not triggering a responsive system, asynchronous request processing errors, component rendering logic issues, cache issues, or concurrent request issues.
By using, correctly handle asynchronous requests, optimize component rendering logic, handle cache issues, and solve concurrent request issues, which can effectively solve these problems.
I hope that the introduction in this article can help you better handle asynchronous requests in Vue development, ensuring data accuracy and user experience.
The above is personal experience. I hope you can give you a reference and I hope you can support me more.