Overview of error handling in applications

---

title: Overview of Error Handling in Applications
date: 2024/10/1
updated: 2024/10/1
author: cmdragon

excerpt:
Abstract: This article describes the error handling mechanisms in Nuxt, including global error handlers and component-level error trapping, as well as error passing rules and handling in production environments

categories:

• front-end development

tags:

• error handling
• Nuxt Applications
• global processor
• Component Error
• production environment
• error transmission
• Vue Mechanism

---

scanningtwo-dimensional barcodeFollow or microsoft search:Programming Intelligence Front-End to Full-Stack Communication and Growth

catalogs

1. summarize
2. global error handler
   • way of defining
   • Parameter description
3. Component level error capture: onErrorCaptured
   • Usage
   • Parameter description
   • Example: Catching errors and displaying friendly messages
4. Error Passing Rules
5. Sources of error capture
6. Situation in the production environment
7. summarize

---

1. General

nuxt provides a number of mechanisms for catching and handling errors in components in order to improve application robustness and user experience. These mechanisms include global error handlers and component-level error-catching hooks.

2. Global error handler

The global error handler is used to catch unhandled errors from any component and centrally manage error logs.

way of defining

When creating an application, the Set the global error handler function:

 = (err, vm, info) => {
  ('Global Error Captured:', err);
};

Parameter description

• err: Objects that catch errors.
• vm: An instance of the Vue component that triggered the error.
• info: A string describing the source of the error (e.g., component name, lifecycle hook, etc.).

3. Component level error capture.onErrorCaptured

onErrorCaptured Hooks support capturing errors from subcomponents within a component, allowing localized handling and management of errors.

Usage

In the component'ssetup function to register an error catching hook:

onErrorCaptured((err, instance, info) => {
  ('Captured an error:', err);
  return false; // Stopping errors from being passed up the chain
});

Parameter description

• err: A captured error object.
• instance: An instance of the component that triggered the error.
• info: A string describing the source of the error.

Example: Catching errors and displaying friendly messages

<template>
  <div>
    <h1>Error Handling Example</h1>
    <p v-if="error">{{ error }}</p>
    <button @click="triggerError">Trigger Error</button>
  </div>
</template>

<script setup>
import { ref, onErrorCaptured } from 'vue';

const error = ref(null);

const triggerError = () => {
  throw new Error('This is a simulated error!');
};

onErrorCaptured((err) => {
   = `An error occurred: ${}`; // Handling error states
  return false; // Prevents errors from continuing up the hierarchy
});
</script>

4. Error transmission rules

• Default behavior: Captured errors are sent to the globalerrorHandler, if not handled by any hooks.
• Error propagation order:: For multipleerrorCaptured Hooks that are called in order from the child component to the parent component. If a hook handles the error, subsequent hooks will no longer be called.
• throw an error: IferrorCaptured The hook itself throws an error that is passed to the globalerrorHandler。

5. Sources of error capture

• Component Rendering
• event handler
• lifecycle hook
• setup function (math.)
• listener
• Custom command hooks
• transition hook

6. Situation in the production environment

In a production environment, theinfo Parameters are shortened to code rather than detailed strings, reducing the risk of information leakage. Developers can refer to the official documentation for the exact meaning of the error code.

7. Summary

Vue's error handling mechanism provides developers with a flexible way to capture and manage errors, combining a global error handler with component-level error capture to improve application stability and user experience.

For the rest of the article, please click to jump to the personal blog page or scan the code to follow or WeChat search:Programming Intelligence Front-End to Full-Stack Communication and Growth, read the full article:Overview of Error Handling in Applications | cmdragon's Blog

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