SoFunction
Updated on 2025-04-11

Solve the problem that Devtools did not detect Vue instances

Solve the issue that Devtools does not detect Vue instances

Devtools is an indispensable debugging tool when developing applications. It can help developers view and operate information such as status, data and methods of Vue components in real time. However, sometimes we may encounter the prompt of "not detected", which means Devtools fails to successfully identify and connect to our Vue app. This article will analyze this problem in detail and provide corresponding solutions and code examples.

When checking if it is loaded correctly, we need to make sure that the Vue library has been properly introduced and available to JavaScript code in the project. The following are the specific steps:

1. Make sure it is loaded correctly

1.1 Directly import into HTML files

For simple projects or quick tests, you can use HTML files for<head>Tag or<body>Pass before the end of the tag<script>Tag introduction CDN resources:

&lt;!DOCTYPE html&gt;
&lt;html lang="en"&gt;
&lt;head&gt;
  &lt;meta charset="UTF-8"&gt;
  &lt;meta name="viewport" content="width=device-width, initial-scale=1.0"&gt;
  &lt;title&gt; App&lt;/title&gt;
  &lt;!-- Introduced --&gt;
  &lt;script src="/npm/vue@2"&gt;&lt;/script&gt;
&lt;/head&gt;
&lt;body&gt;
  &lt;div &gt;{{ message }}&lt;/div&gt;

  &lt;script&gt;
    // You can now create a Vue instance    new Vue({
      el: '#app',
      data: {
        message: 'Hello from !'
      }
    });
  &lt;/script&gt;
&lt;/body&gt;
&lt;/html&gt;

1.2 Configuring import in build tools (such as Webpack)

If you are developing using a module packaging tool like Webpack, you need to enter the project (e.g.) through ES6importStatements are introduced into the Vue library and registered to the global scope or used as local dependencies.

// (Webpack project entry file)import Vue from 'vue'; // Import Vue
// If your application is built on a single root componentimport App from './';

new Vue({
  render: h =&gt; h(App),
}).$mount('#app'); // Mount Vue instance on DOM element

Meanwhile, in the Webpack configuration file (e.g.) to ensure processing.vueThe loaders related to files and other JavaScript resources are correctly configured so that Vue single-file components can be recognized and compiled.

1.3 Check and Verification

Either way, you can verify that Vue is loading successfully by running the following command in the console:

(Vue); // Execute this line of code in the Console panel of the browser developer tool

If the information of the Vue object is output, it means that it has been loaded correctly. Also, try creating a basic Vue instance and see if it works properly. If everything works, you should be able to successfully take over and manage the data and instructions you define in the template.

2. Check the Devtools extension installation status

After making sure the app is loading correctly, checking and configuring browser extensions is the next critical step if Devtools still does not detect Vue instances. Here are the detailed guides:

2.1 Open the Chrome browser extension management page

First, please open Google Chrome and enter it in the address barchrome://extensions/And press Enter. This will take you to Chrome's extension management interface, where you can view all installed extension plugins and their status.

2.2 Confirm whether Devtools is installed and enabled

On this page, scroll through all the extensions already listed to find "Devtools" or applications with similar names and icons. Confirm that it has been installed successfully and that the status is enabled (usually there will be a checkbox indicating that it is enabled). If the plugin exists but is not enabled, click the Enable button next to the plugin to activate it.

2.3 Install Devtools

If you find that Devtools is not installed, you can directly access the Chrome Web Store to install it. GoChrome Web Store, search for "Devtools", find the officially released plug-in and click "Add to Chrome" to complete the installation process.

2.4 Manual installation or CRX file installation

Sometimes, you may need to install Devtools manually, for example by downloading CRX files. In this case, you need to follow these steps:

  • In the upper right corner of the extension management page (chrome://extensions/), check the "Developer Mode" option.
  • Click the "Load the unzipped extension" button, and a file selection dialog box will pop up.
  • Navigate to the folder where the Devtools extension you downloaded and unzipped previously and select the directory containing the files.
  • After clicking "Select Folder", Chrome will automatically load this non-store extension.

2.5 Verify installation

No matter which way you install it, once Devtools is installed and enabled, you should be able to see the Devtools icon in the upper right corner of your browser. When you open a webpage built using, if Devtools recognizes the Vue app, its icon becomes active (such as green).

Finally, if you still have the "not detected" issue, try reloading the Vue app page, or restarting the browser to see if the issue is resolved. At the same time, check whether your Vue application is running in the development environment, because Vue in the production environment may be optimized, resulting in Devtools not being recognized normally.

3. Configure extended permissions

In some cases, Devtools may require specific permissions to properly detect and debug applications. Although most of the time, the default extended permission settings are sufficient to meet the needs, in some special scenarios, such as when using a non-standard configuration or running environment, you may need to check and adjust the permissions of Devtools.

How to view and adjust extended permissions:

  1. Open Chrome and accesschrome://extensions/to enter the extension management page.
  2. Find the Devtools plugin in the list and click the "Details" button after the plugin name (usually a small icon with a small arrow) to expand the detailed extension information interface.
  3. In this page, scroll to the Permissions section, where all permissions requested by the extension are listed. Common permissions include "reading and changing data from all websites you visit", etc. These permissions are necessary for Devtools to identify and operate Vue instances in web pages.
  4. If you find that permissions are disabled or missing, try enabling the relevant permissions, then restart your browser and refresh the application page.

Please note that Devtools generally does not require manual permission adjustment to work properly. Additional configuration may only occur when your application has special security policies or other special circumstances. If you do encounter "not detected" due to permission issues, it is recommended to consult Devtools' official documentation or community forum to find out if there is a specific solution.

Also, if you are debugging in a local development environment, make sure the application is running in development mode, as some optimizations in the production environment may prevent Devtools from correctly detecting Vue instances. Also, make sure that the library has been loaded successfully and that your Vue instance has been properly initialized and mounted.

4. Modify

4.1 Document Introduction

It is the core configuration file of Chrome extension, which defines the core configurations of the plug-in's basic information, permission requirements, running environment, and scripts triggered by various event. For every Chrome extension,Files are essential, and they are equivalent to the "list" or "configuration manual" of the application, allowing the browser to know how to load, manage and execute various functions of the extended ones.

4.2 The role of persistent settings

Early versions of Chrome extensions allow developers to passSettings inProperties to control whether the extended background script continues to run. IfpersistentSet totrue, it means that the extended background page will always remain active, and will remain running even if there is no active window or tab association. This is useful for extensions that need to always be listening or perform tasks regularly.

However, since Chrome 73, Google has adjusted the extended background page behavior for performance optimization and resource management reasons. Persistent background pages are no longer supported, and the "event-driven" background pages are recommended. The event page is only awakened when it needs to respond to specific events (such as messaging, network requests, etc.), thereby reducing unnecessary resource usage.

For Devtools, although the persistence settings mentioned above may not be suitable for solving the "not detected" problem, understand and configure correctly when dealing with other types of extensionsIn-housebackgroundThe part is still crucial.

4.3 Troubleshooting of Devtools extension

In fact, Devtools does not depend onFields to detect Vue instances. If you encounter the problem of "not detected", you should troubleshoot from other perspectives, such as confirming whether the library has been successfully introduced, whether the Vue instance has been initialized correctly, and whether the Devtools extension itself is working normally. Normally, Devtools does not need to be modifiedFiles can work with most Vue applications.

5. Permission settings and refresh pages

After confirming that the Devtools extension is correct, restart the browser and refresh the Vue application page. If the Vue instance is still not recognized at this time, try the following troubleshooting steps:

  • Check if the Vue app is inNon-production environmentrun. Some optimized configurations (such as Vue CLImode: 'production') may cause the source code to be compressed and confused, which will affect the recognition ability of Devtools.

  • Make sure your Vue instance is accessible globally. For example, create a Vue instance in the main entrance file:

new Vue({
  el: '#app',
  data: {
    message: 'Hello, !'
  }
})
  • If the Vue application is developed based on Single File Components (SFC), please make sure that these components have been correctly compiled and mounted to the DOM.

Handle special circumstances

In some cases, it may be due to the permission settings of the Devtools extension or the special configuration of the Vue application itself, which may be unrecognized. However, it is usually not necessary to manually adjust the extension permissions or modify the file, because Devtools was designed with most application scenarios in mind at the beginning.

6. Conclusion

After the above steps, most "not detected" problems should be solved. If the problem persists, it is recommended to consult Devtools' official documentation for the latest solutions. You can also seek help within the Vue community to share specific project configuration and implementation details so that others can more accurately locate the problem.

Remember that good development practices and understanding of the underlying mechanisms of the framework are the key to avoiding such problems. Always maintaining the version update of its related tools is also an important part of ensuring a smooth development experience.

The above is the detailed content to solve the problem that Devtools did not detect Vue instances. For more information about Devtools' Vue instances, please pay attention to my other related articles!