Files
react/packages/react-devtools-extensions/src/injectGlobalHook.js
T

167 lines
5.6 KiB
JavaScript

/* global chrome */
import nullthrows from 'nullthrows';
import {installHook} from 'react-devtools-shared/src/hook';
import {SESSION_STORAGE_RELOAD_AND_PROFILE_KEY} from 'react-devtools-shared/src/constants';
import {sessionStorageGetItem} from 'react-devtools-shared/src/storage';
function injectCode(code) {
const script = document.createElement('script');
script.textContent = code;
// This script runs before the <head> element is created,
// so we add the script to <html> instead.
nullthrows(document.documentElement).appendChild(script);
nullthrows(script.parentNode).removeChild(script);
}
let lastDetectionResult;
// We want to detect when a renderer attaches, and notify the "background page"
// (which is shared between tabs and can highlight the React icon).
// Currently we are in "content script" context, so we can't listen to the hook directly
// (it will be injected directly into the page).
// So instead, the hook will use postMessage() to pass message to us here.
// And when this happens, we'll send a message to the "background page".
window.addEventListener('message', function onMessage({data, source}) {
if (source !== window || !data) {
return;
}
switch (data.source) {
case 'react-devtools-detector':
lastDetectionResult = {
hasDetectedReact: true,
reactBuildType: data.reactBuildType,
};
chrome.runtime.sendMessage(lastDetectionResult);
break;
case 'react-devtools-extension':
if (data.payload?.type === 'fetch-file-with-cache') {
const url = data.payload.url;
const reject = value => {
chrome.runtime.sendMessage({
source: 'react-devtools-content-script',
payload: {
type: 'fetch-file-with-cache-error',
url,
value,
},
});
};
const resolve = value => {
chrome.runtime.sendMessage({
source: 'react-devtools-content-script',
payload: {
type: 'fetch-file-with-cache-complete',
url,
value,
},
});
};
fetch(url, {cache: 'force-cache'}).then(
response => {
if (response.ok) {
response
.text()
.then(text => resolve(text))
.catch(error => reject(null));
} else {
reject(null);
}
},
error => reject(null),
);
}
break;
case 'react-devtools-inject-backend':
const script = document.createElement('script');
script.src = chrome.runtime.getURL('build/react_devtools_backend.js');
document.documentElement.appendChild(script);
script.parentNode.removeChild(script);
break;
}
});
// NOTE: Firefox WebExtensions content scripts are still alive and not re-injected
// while navigating the history to a document that has not been destroyed yet,
// replay the last detection result if the content script is active and the
// document has been hidden and shown again.
window.addEventListener('pageshow', function({target}) {
if (!lastDetectionResult || target !== window.document) {
return;
}
chrome.runtime.sendMessage(lastDetectionResult);
});
const detectReact = `
window.__REACT_DEVTOOLS_GLOBAL_HOOK__.on('renderer', function({reactBuildType}) {
window.postMessage({
source: 'react-devtools-detector',
reactBuildType,
}, '*');
});
`;
const saveNativeValues = `
window.__REACT_DEVTOOLS_GLOBAL_HOOK__.nativeObjectCreate = Object.create;
window.__REACT_DEVTOOLS_GLOBAL_HOOK__.nativeMap = Map;
window.__REACT_DEVTOOLS_GLOBAL_HOOK__.nativeWeakMap = WeakMap;
window.__REACT_DEVTOOLS_GLOBAL_HOOK__.nativeSet = Set;
`;
// If we have just reloaded to profile, we need to inject the renderer interface before the app loads.
if (sessionStorageGetItem(SESSION_STORAGE_RELOAD_AND_PROFILE_KEY) === 'true') {
const rendererURL = chrome.runtime.getURL('build/renderer.js');
let rendererCode;
// We need to inject in time to catch the initial mount.
// This means we need to synchronously read the renderer code itself,
// and synchronously inject it into the page.
// There are very few ways to actually do this.
// This seems to be the best approach.
const request = new XMLHttpRequest();
request.addEventListener('load', function() {
rendererCode = this.responseText;
});
request.open('GET', rendererURL, false);
request.send();
injectCode(rendererCode);
}
// Inject a __REACT_DEVTOOLS_GLOBAL_HOOK__ global for React to interact with.
// Only do this for HTML documents though, to avoid e.g. breaking syntax highlighting for XML docs.
// We need to inject this code because content scripts (ie injectGlobalHook.js) don't have access
// to the webpage's window, so in order to access front end settings
// and communicate with React, we must inject this code into the webpage
switch (document.contentType) {
case 'text/html':
case 'application/xhtml+xml': {
injectCode(
';(' +
installHook.toString() +
'(window))' +
saveNativeValues +
detectReact,
);
break;
}
}
if (typeof exportFunction === 'function') {
// eslint-disable-next-line no-undef
exportFunction(
text => {
// Call clipboard.writeText from the extension content script
// (as it has the clipboardWrite permission) and return a Promise
// accessible to the webpage js code.
return new window.Promise((resolve, reject) =>
window.navigator.clipboard.writeText(text).then(resolve, reject),
);
},
window.wrappedJSObject.__REACT_DEVTOOLS_GLOBAL_HOOK__,
{defineAs: 'clipboardCopyText'},
);
}