Is it possible to get an overview of running Javascript Web Workers either with browser console, developer tools or with a command?
I use an external library which uses workers and want to make sure it runs correctly, but I don't know how the worker is called and have no variable pointing to it.
Yes, you can see the list of current workers using the developer tool in Firefox and Chrome (I'm not aware of other browsers).
In Firefox developer tools, they are in the right hand pane, under the Workers section of the Debugger tab.
In Chrome developer tools, they are in the right hand pane, under the Threads section of the Sources tab.
You can click on a worker to open up its console and debugger.
Hope it helps!!
Related
I'm looking for a way to open the WebKit “developer tools” from a script attached to a web-page. I need solutions for both Google Chrome and Safari, that will open the developer-tools pane if it's not already open, and (hopefully, if you can figure out how) also switch to a particular tab/section of said pane upon opening.
(Use-case, if anyone's interested: I want to open the console.log output-window if there's been an error and a developer is looking at the page; this particular page will be the output of some JavaScript unit-tests.)
I'm setting a bounty on this question because it's obviously one that hasn't been answered to anyone's satisfaction before, and the answer is a hairy one. Please don't answer it unless you have a real answer that both: 1) works in both browsers, and 2) doesn't require private extension APIs that won't work from a static web-page.
See (related, but specific to Chrome, and extensions): Can I programmatically open the devtools from a Google Chrome extension?
Simply: You can't.
The Dev Tools are not sandboxed (unlike any web page), thus granting sandboxed environments the power to open and control an unsandboxed environment is a major security design flaw.
I hope this answers your question :-)
You cannot directly use the Chrome's Dev Tools from your web pages. It is bundled with the browser.
But you can use it like a regular web application. Go to Chrome Developer Tools, then go to Contributing. You will find help on using Dev Tools for your app.
Setting up
Install Chrome Canary on Mac OS / Windows or download the latest Chromium build from the Chromium continuous builds archive on Linux
Clone Blink git repo from https://chromium.googlesource.com/chromium/blink.git
Set up a local web server that would serve files from WebKit/Source/WebCore/inspector on some port (8090)
Running
Run one copy of Chrome Canary with the following command line flags: --remote-debugging-port=9222 --user-data-dir=blink/chromeServerProfile --remote-debugging-frontend="http://localhost:8090/front_end/inspector.html". These flags cause Chrome to allow websocket connections into localhost:9222 and to serve the front-end UI from your local git repo. (Adjust the path to chromeServerProfile to be some writable directory in your system).
Open a sample page (eg www.chromium.org).
Run a second copy of Chrome Canary with the command line flag: --user-data-dir=/work/chromeClientProfile. Open http://localhost:9222. Among the thumbnails you will see the sample page from the other browser instance. Click on it to start remote debugging your sample page.
The DevTools web page that opens is served from the remote-debugging-frontend in the first browser instance, which serves from the git repo your local filesystem. Debug this Devtools Web page and edit its source like any other web app.
I hope this is what you need.
There's no way to control the web developer tool from an in-page script, other than through the Console API which provides mostly logging facilities. Letting scripts control more than that would be a serious security issue, since it would allow a web page to control parts of the browser.
The only API remotely related to what you're trying to do is the debugger command, which switches to the script pane only if the developer tools were already open.
But who are you trying to develop this feature for?
If it's for developers working on the site, then it's better to just use the existing developer tools manually, by setting breakpoints, or the pause on exceptions toggle.
If it's for end users, don't. Unless your site is supposed to be used by highly technical web developers, you're only going to scare away users if the developer tools suddenly pop up with errors.
If you really want to show errors you can implement your own logging framework and the UI for error reporting, which works with basic JS and doesn't depend on a specific browser environment.
here's another answer that proposes a solution to your mentioned use case/objective (detecting errors, getting & displaying console logs) and not the not possible objective in the title.
you can make and use a console wrapper and use it in your code
and/or you can monkey patch the console functions if you use/import external js, but you need to apply it before loading them.
No, Any secure Browser will not allow a script to open an extension, as it leads to insecurity.
But, You may design an Add-On/extension OR Console API's to do the same.. for specific site.
Create an Add-On like this to achieve that requirement.
You can try sending keys 'CTRL' + SHIFT' + 'I'
that may work for Chrome any FireFox (in I.E you need to use 'F12'
I am using it when required as few utils in this add-on use to work better then the built-in.
EDIT:
Now a days Chrome is advanced with many new advancements source.
I hope this helps!
Hate to answer such an old question, but was surprised to not see this as an answer, so I thought I'd add it in case it can help someone in the future.
Assuming you have access to the source code, you can place an alert("open devtools"); statement immediately before the first line you're interested in debugging. This alert will give you an opportunity to open DevTools and set a breakpoint on that first line before clearing the alert thus allowing the code to continue and hitting the breakpoint.
I have a JavaScript app running in my desktop Chrome browser which is reading and writing to Firebase. I'd like to get a sense of how much traffic it uses (vs any local caching) and I figured I could just watch in the Chrome Inspector.
I'm not seeing any such traffic. I assume I need to tweak some Inspector setting, but it looks like I have everything turned on and nothing filtered.
How can I see this traffic? (For my current simple needs, I'd much rather do so in Chrome, and not have to fire up WireShark)
Firebase uses a websocket to communicate with clients. In the devtool's networking tab, filter by "WS" (websocket) and you should see the connection that Firebase is using.
There is a great extension for Chrome called 'GTM/GA Debug' that has a readout for Firebase hits. When using the extension in Chrome Dev Tools, look at the tab named GA4F (Google Analytics for Firebase). It is very helpful for debugging.
I'm looking for a way to open the WebKit “developer tools” from a script attached to a web-page. I need solutions for both Google Chrome and Safari, that will open the developer-tools pane if it's not already open, and (hopefully, if you can figure out how) also switch to a particular tab/section of said pane upon opening.
(Use-case, if anyone's interested: I want to open the console.log output-window if there's been an error and a developer is looking at the page; this particular page will be the output of some JavaScript unit-tests.)
I'm setting a bounty on this question because it's obviously one that hasn't been answered to anyone's satisfaction before, and the answer is a hairy one. Please don't answer it unless you have a real answer that both: 1) works in both browsers, and 2) doesn't require private extension APIs that won't work from a static web-page.
See (related, but specific to Chrome, and extensions): Can I programmatically open the devtools from a Google Chrome extension?
Simply: You can't.
The Dev Tools are not sandboxed (unlike any web page), thus granting sandboxed environments the power to open and control an unsandboxed environment is a major security design flaw.
I hope this answers your question :-)
You cannot directly use the Chrome's Dev Tools from your web pages. It is bundled with the browser.
But you can use it like a regular web application. Go to Chrome Developer Tools, then go to Contributing. You will find help on using Dev Tools for your app.
Setting up
Install Chrome Canary on Mac OS / Windows or download the latest Chromium build from the Chromium continuous builds archive on Linux
Clone Blink git repo from https://chromium.googlesource.com/chromium/blink.git
Set up a local web server that would serve files from WebKit/Source/WebCore/inspector on some port (8090)
Running
Run one copy of Chrome Canary with the following command line flags: --remote-debugging-port=9222 --user-data-dir=blink/chromeServerProfile --remote-debugging-frontend="http://localhost:8090/front_end/inspector.html". These flags cause Chrome to allow websocket connections into localhost:9222 and to serve the front-end UI from your local git repo. (Adjust the path to chromeServerProfile to be some writable directory in your system).
Open a sample page (eg www.chromium.org).
Run a second copy of Chrome Canary with the command line flag: --user-data-dir=/work/chromeClientProfile. Open http://localhost:9222. Among the thumbnails you will see the sample page from the other browser instance. Click on it to start remote debugging your sample page.
The DevTools web page that opens is served from the remote-debugging-frontend in the first browser instance, which serves from the git repo your local filesystem. Debug this Devtools Web page and edit its source like any other web app.
I hope this is what you need.
There's no way to control the web developer tool from an in-page script, other than through the Console API which provides mostly logging facilities. Letting scripts control more than that would be a serious security issue, since it would allow a web page to control parts of the browser.
The only API remotely related to what you're trying to do is the debugger command, which switches to the script pane only if the developer tools were already open.
But who are you trying to develop this feature for?
If it's for developers working on the site, then it's better to just use the existing developer tools manually, by setting breakpoints, or the pause on exceptions toggle.
If it's for end users, don't. Unless your site is supposed to be used by highly technical web developers, you're only going to scare away users if the developer tools suddenly pop up with errors.
If you really want to show errors you can implement your own logging framework and the UI for error reporting, which works with basic JS and doesn't depend on a specific browser environment.
here's another answer that proposes a solution to your mentioned use case/objective (detecting errors, getting & displaying console logs) and not the not possible objective in the title.
you can make and use a console wrapper and use it in your code
and/or you can monkey patch the console functions if you use/import external js, but you need to apply it before loading them.
No, Any secure Browser will not allow a script to open an extension, as it leads to insecurity.
But, You may design an Add-On/extension OR Console API's to do the same.. for specific site.
Create an Add-On like this to achieve that requirement.
You can try sending keys 'CTRL' + SHIFT' + 'I'
that may work for Chrome any FireFox (in I.E you need to use 'F12'
I am using it when required as few utils in this add-on use to work better then the built-in.
EDIT:
Now a days Chrome is advanced with many new advancements source.
I hope this helps!
Hate to answer such an old question, but was surprised to not see this as an answer, so I thought I'd add it in case it can help someone in the future.
Assuming you have access to the source code, you can place an alert("open devtools"); statement immediately before the first line you're interested in debugging. This alert will give you an opportunity to open DevTools and set a breakpoint on that first line before clearing the alert thus allowing the code to continue and hitting the breakpoint.
I'm currently using the "Developer mode" on the chrome://extensions page of the chromium browser, loading it by clicking on "Reload (Ctrl+R)".
I'd like to be able to make a change to my unpacked chrome extension and load it into the browser in an automated way, especially since I'm testing the extension on a virtual machine so doing all this completely headlessly would be ideal. However, I would at least like to avoid having to click every time I want to load my extension, and I'd like to be able to collect any errors produced into a file/tty.
What is the best way of doing this? Does chrome provide tools for automating extension building and testing?
Regarding the other question linked below:
It doesn't really address my problem, since I am looking for a way to get console output, stack traces and any output generated by the extension reload to be accessible via a file/stream in my OS, as opposed to being displayed in a chromium browser window. The linked answers provide a way to reload the extension programmatically, but not much else.
There are a few avenues for you to research.
You could look into enabling logging with a high verbosity. In principle, I would think there is a level that echoes console output; I'm no expert though.
You could use Native Messaging to speak to a daemon that will log things for you; the downside is that you probably can't catch errors this way.
You could take this one step further and create an extension that attaches to your target extension with Remote Debugging protocol (which provides the same info as DevTools) using the chrome.debugger API, and then log stuff with Native Messaging.
Or, you could eschew using an extension as a supervisor and just use/write an external Remote Debugging client.
I'm looking for a way to open the WebKit “developer tools” from a script attached to a web-page. I need solutions for both Google Chrome and Safari, that will open the developer-tools pane if it's not already open, and (hopefully, if you can figure out how) also switch to a particular tab/section of said pane upon opening.
(Use-case, if anyone's interested: I want to open the console.log output-window if there's been an error and a developer is looking at the page; this particular page will be the output of some JavaScript unit-tests.)
I'm setting a bounty on this question because it's obviously one that hasn't been answered to anyone's satisfaction before, and the answer is a hairy one. Please don't answer it unless you have a real answer that both: 1) works in both browsers, and 2) doesn't require private extension APIs that won't work from a static web-page.
See (related, but specific to Chrome, and extensions): Can I programmatically open the devtools from a Google Chrome extension?
Simply: You can't.
The Dev Tools are not sandboxed (unlike any web page), thus granting sandboxed environments the power to open and control an unsandboxed environment is a major security design flaw.
I hope this answers your question :-)
You cannot directly use the Chrome's Dev Tools from your web pages. It is bundled with the browser.
But you can use it like a regular web application. Go to Chrome Developer Tools, then go to Contributing. You will find help on using Dev Tools for your app.
Setting up
Install Chrome Canary on Mac OS / Windows or download the latest Chromium build from the Chromium continuous builds archive on Linux
Clone Blink git repo from https://chromium.googlesource.com/chromium/blink.git
Set up a local web server that would serve files from WebKit/Source/WebCore/inspector on some port (8090)
Running
Run one copy of Chrome Canary with the following command line flags: --remote-debugging-port=9222 --user-data-dir=blink/chromeServerProfile --remote-debugging-frontend="http://localhost:8090/front_end/inspector.html". These flags cause Chrome to allow websocket connections into localhost:9222 and to serve the front-end UI from your local git repo. (Adjust the path to chromeServerProfile to be some writable directory in your system).
Open a sample page (eg www.chromium.org).
Run a second copy of Chrome Canary with the command line flag: --user-data-dir=/work/chromeClientProfile. Open http://localhost:9222. Among the thumbnails you will see the sample page from the other browser instance. Click on it to start remote debugging your sample page.
The DevTools web page that opens is served from the remote-debugging-frontend in the first browser instance, which serves from the git repo your local filesystem. Debug this Devtools Web page and edit its source like any other web app.
I hope this is what you need.
There's no way to control the web developer tool from an in-page script, other than through the Console API which provides mostly logging facilities. Letting scripts control more than that would be a serious security issue, since it would allow a web page to control parts of the browser.
The only API remotely related to what you're trying to do is the debugger command, which switches to the script pane only if the developer tools were already open.
But who are you trying to develop this feature for?
If it's for developers working on the site, then it's better to just use the existing developer tools manually, by setting breakpoints, or the pause on exceptions toggle.
If it's for end users, don't. Unless your site is supposed to be used by highly technical web developers, you're only going to scare away users if the developer tools suddenly pop up with errors.
If you really want to show errors you can implement your own logging framework and the UI for error reporting, which works with basic JS and doesn't depend on a specific browser environment.
here's another answer that proposes a solution to your mentioned use case/objective (detecting errors, getting & displaying console logs) and not the not possible objective in the title.
you can make and use a console wrapper and use it in your code
and/or you can monkey patch the console functions if you use/import external js, but you need to apply it before loading them.
No, Any secure Browser will not allow a script to open an extension, as it leads to insecurity.
But, You may design an Add-On/extension OR Console API's to do the same.. for specific site.
Create an Add-On like this to achieve that requirement.
You can try sending keys 'CTRL' + SHIFT' + 'I'
that may work for Chrome any FireFox (in I.E you need to use 'F12'
I am using it when required as few utils in this add-on use to work better then the built-in.
EDIT:
Now a days Chrome is advanced with many new advancements source.
I hope this helps!
Hate to answer such an old question, but was surprised to not see this as an answer, so I thought I'd add it in case it can help someone in the future.
Assuming you have access to the source code, you can place an alert("open devtools"); statement immediately before the first line you're interested in debugging. This alert will give you an opportunity to open DevTools and set a breakpoint on that first line before clearing the alert thus allowing the code to continue and hitting the breakpoint.