React Developer Tools is a Chrome extension that allows you to inspect the React component hierarchy in the Chrome Developer Tools (formerly WebKit Web Inspector).
Install the extension from Chrome Web Store
If you inspect an element or launch the developer tools on a React page, you should see an extra tab called React in the inspector.
Clone the GitHub repository.
git clone git@github.com:facebook/react-devtools.git
Clone the blink submodule.
git submodule update --init
Open the URL chrome://extensions/ in your browser.
Check the box for Developer Mode
Click the button Load unpacked extension...
Select the folder where you downloaded the repository.
The extension is now installed.
The "React" tab won't show up if React can't communicate with the
devtools. When the page loads, the devtools sets a global named
__REACT_DEVTOOLS_GLOBAL_HOOK__, then React communicates with that
hook during initialization.
(In React 0.11 and older, it was necessary to expose a global called React
for the devtools to function.)
You can test this on the React website or by inspecting Facebook.
Due to a bug in Chrome,
devtools extensions are unable to use localStorage if the "Block third-party
cookies and site data" option is checked in the Chrome content settings. Until
this bug is fixed, please make sure this preference is unchecked.
You should have a new tab called React in your Chrome DevTools. This shows you the root React components that was rendered on the page, as well as the subcomponents that they ended up rendering.
By selecting one of the components in the tree you can inspect and edit its current props and state in the panel on the right. In the breadcrumbs you can inspect the selected Component, the Component that created it, the Component that created that one, and so on.
If you inspect a React element on the page using the regular Elements tab, then switch over to the React tab, that element will be automatically selected in the React tree.
Similarly, if you have a breakpoint within the render phase of a Component, that will be automatically selected in the React tab. This allows you to step through the rendering tree and see how one Component affects another one.
By breaking on errors, you can easily find which component threw an error during rendering, and what props lead to it.
Open the Chrome DevTools on any React page by inspecting an element.
In a different tab goto chrome://inspect/. Open the last section called Others. This contain your DevTools instance. Click the inspect link next to it. That should open up another DevTools instance, which is inspecting the first one, including the React extension. Inception.
If you don't have a simple React page available you can use the built-in test page. Open the URL chrome://extensions/ again. Look for the unique ID of the extension. E.g:
chrome-extension://fmkadmapgofadopljbjfkapdkoienihi/tests/page.html
The purpose of this project is to trail the DevTools of the Chromium project. Therefore the project is structured similarly. For example this project doesn't use a module system. Each file is inserted using a script tag in the global scope of the page. Files are isolated by global namespaces.
Please read the Structure document for more information about the folder structure of the project.
There's only so much we can cram in here. To read more about the community and guidelines for submitting pull requests, please read the Contributing document.