how to check tab load failed

browser-tab, google-chrome, google-chrome-extension, javascript

Solution

There's no direct way to catch these errors. However, I've just created a method to accomplish the goals:

- Use `chrome.tabs.onUpdated` (with a `d`!). This event is fired twice, when the page is initializing (`"loading"`), and when the DOM has loaded (`"complete"`).

- Use `chrome.tabs.executeScript(tabId, {file: fileName}, fn_callback);` The second argument has to be an object, containing either `"file"`, or `"code"`. The third argument, a function, is always executed after finishing the script injection. Now, the real implementation:

- Execute the content script (using `chrome.tabs.executeScript`).

- In the injected content script, define an `onMessage` event.

- In the callback function of `chrome.tabs.executeScript`, follow these steps:

- Use `var exec_error = setTimeout(onError, 100);` to defer the execution of your `onError` method. Choose an appropriately small delay (100), and save a reference to this timeout in a variable, `exec_error`.

- Use `chrome.tabs.sendMessage(tabId, func)` to send a message to the tab.

- In callback function `func`, add this logic:

- Validate the response (is the event not created by another part of the extension?)

- `clearTimeout(exec_error)`

- `onSuccess()`

- When an error occurs, the `onMessage` event as defined in 2. will not be injected. Hence, the tab will not respond as expected, and the time-out is not cleared. As a result, `onError` will be executed. Otherwise, the timeout is cleared, and `onSuccess` is executed.

Code (e.g. background script):

chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab) {
    // This event fires twice: loading, and complete.
    // If we're loading, terminate function, and wait for "complete"
    if (changeInfo.status === 'loading') return;

    // On error and on success, this happens:
    function onError() {
        console.log('Error injecting the content script!');
    }
    function onSuccess() {
        console.log('Successfully injected content script!');
    }

    // Execute scripts
    chrome.tabs.executeScript(tabId, {
        file: 'test_access.js'
    }, function() {
        // This function always fires *after* the attempt to run the code
        var exec_error = setTimeout(onError, 100);
        chrome.tabs.sendMessage(tabId, 'Are you there?', function(yes_no) {
            if (yes_no === 'Yes') {
                clearTimeout(exec_error);
                onSuccess();
            }
        });
    });
});

`test_access.js`

chrome.extension.onMessage.addListener(function(req, sender, respond) {
   if (req === 'Are you there?') {
       respond('Yes');
   }
});
// Rest of your content script's logic, eg:
alert(location.href);

Problem

I need do something on tabs updated, like check if the page load correct, and replace something inside the page. here is my code ``` // background.js chrome.tabs.onUpdate.addListener(function(tabId, changeInfo, tab){ try{ chrome.tabs.executeScript(tabId, filename); } catch(e) { // 1. when I open a new tab // 1. Error during tabs.executeScript: Unknown error. // 2. when I request a url not arrive-able. // 2. Error during tabs.executeScript: Cannot access contents of url // "data:text/html,chromewebdata". Extension manifest must request // permission to access this host. // but I can't catch these errors, they just appers in background console. } }); ``` I try to executeScript when it upload, but if the current tab is chrome://newtab or chrome error page, I can't do this, but I can't catch the error.

Original source