Firefox Dev Tools: Box model highlighter, Web Console improvements | Hacker News Reader

Firefox Dev Tools: Box model highlighter, Web Console improvements

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83 pointsrnyman52 comments

I'm going to guess that Chrome DevTools is going to fall behind Firefox by end of this year.

Today it's not possible for me to make the switch. There are some features that Firefox devtools is lacking from DevTools.

Here are some features I'm missing:

    Break on attribute or subtree modification
    HTML Node drag and drop (yup! Chrome DevTools have it)
    XPath (I use it for testing)
    FPS monitor and force repaint

Thanks for the info. What are you wanting to do with xpath? The console supports the $x function, like $x("//body"). Also, HTML node drag and drop is on the radar here: https://bugzilla.mozilla.org/show_bug.cgi?id=858038

I want to get XPath from a node. I use it in WebDriverJS.

Good to see drag and drop coming.

There was some features that I loved. It's not fair to not mention those:

    CSS autocomplete is much better than Chrome’s
    Code Editor’s Search is just amazing!
    The filter for computed CSS properties is very handy for my work
    Black Theme is great! Please make it easy to write custom themes

One little request, in console. ⌘+K should clean the console.

We have Ctrl-L for clear output.

⌘+K is consistent across other apps on OS X (e.g. Terminal)

We've had long discussions and arguing over cmd-k, ctrl-L, and all the shortcuts we could use. cmd-k takes over the search field focus.

This is a bitter pill: any shortcut we choose is a different kind of 'wrong'.

I'd throw in a vote for cmd+k to clear

But ^L is also consistent with Terminal, across all platforms, at least in bash and other programs that use readline. :)

I've filed https://bugzilla.mozilla.org/show_bug.cgi?id=987877 for adding a Copy XPath menu item in the inspector

A long time ago I wrote a Firefox plugin to get an XPath:

https://addons.mozilla.org/en-US/firefox/addon/xpath-checker...

It's open source, so perhaps you could reuse the code from WebDriver:

https://code.google.com/p/xpathchecker/

I'm missing localStorage inspecting and editing. (If it's already there, please tell where :), I haven't really used Firefox developer tools much).

In the console you can type: inspect(localStorage)

Thanks, but that's not usable enough for me.

A storage inspector is not part of the tools yet. Some of the functionality for this has landed, but the frontend is still being worked on here: https://bugzilla.mozilla.org/show_bug.cgi?id=970517.

That seems to be premature. Depends what you consider a DevTool. Chrome still has far better profiling/tracing tools for performance analysis. The latest Chrome versions even let you hover over functions and view what the V8 JIT thought of them (e.g. deoptimized and why). Even relatively low hanging fruit, like debugging WebWorkers is missing from FF. I see tons of missing stuff that Chrome DevTools has that FF is missing. It doesn't have something like the Timeline tab for tracking memory/framerate over time. I don't see stuff like HTML5 FileSystem/IndexDB/localStorage browsing. SourceMap support doesn't match Chrome. Etc.

FF seems to do better with the DOM/Designer portion of tooling, but from a JS-heavy coder perspective it seems behind.

Like we aren't working on all those things ;)

Sometimes I wonder if Chrome and Mozilla could standardize on some DevTool APIs, like JVMs standardized on JVMTI/JPDA, so that a portion of the code could be shared and people could build JS dev-tooling that would work with either browser.

Obviously, there's lots of stuff that is tied to internals, especially when it comes to profiling and native code bindings, but it seems like something could be done.

A good start would be for JS VMs to adopt a standard debugger protocol so that attaching a tool to the JS debugger would be browser independent.

You mean catch up to where DevTools are right now, by the end of the year? Firefox's tools have been behind Chrome's for years, I really don't see how Chrome's will "fall behind". You know Chrome has people working on it too, right?

Have you ever opened a bug for Chrome DevTools? I opened one for filtering computed CSS properties a year ago. It's not even triaged yet!

As a GWT maintainer I would be overjoyed if Firefox would simply match Chrome as a solid, fast JavaScript debugger that supports sourcemaps well for large apps. The announced bells and whistles aren't going to help my users if they can't even debug their code.

I love all the work the Firefox team is doing here over the last year. Things have improved so much, its terrific. These are the things Firefox needs before I could start to consider it as a primary development tool:

- Performance analyzation

- Resource management (cookies, local storage, etc)

- Option to completely disable cache when dev tools are open

- Ability to search the document in the inspector

I'm sure they'll get there before too long.

Already has an option to disable the cache. Advanced settings.

Thank you!

Edit: I can't find it. I see I can disable the cache completely, but that's not really what I want. Its nice to only disable it when the dev tools are open. I don't want to have to go to advance settings and clear it every time.

Why specifically "when the dev tools are open"? That seems like an unusually specific request.

This is how Chrome DevTools do it (by default), and it's incredibly useful. When I'm just browsing websites I want the cache enabled, but when I'm working on a site (in which case I usually have the DevTools opened) I want the cache disabled. In fact, I now just open the DevTools when I want to temporarily disable caching -- because the keyboard shortcut is so ingrained it's a lot easier to do that then find the overall browser setting itself.

I know that's how Chrome DevTools does it, but "because that's how Chrome DevTools does it" is not a good answer to the question "why specifically when the DevTools are open".

Because you don't want to disable caching of every other sites when you are not wearing your developer hat, just a "regular user surfing internet" hat.

Sounds like a case for using separate Firefox profiles, one for each "hat."

Why do that when I can just press "F12"?

That's not how it works. It only disables the tab you are working in.

This is exactly the point -- when you're developing a site, you want caching disabled on that site, but then when you're browsing another site just as a regular surfer you do not want caching disabled. Since generally when you're working on a site, you have DevTools opened, and generally when you're just browsing the web you do not have DevTools open, this is very nice.

I disagree with this:

> when you're developing a site, you want caching disabled on that site

I don't know why you say that. I only want caching disabled if I'm debugging something I think might be caused by caching.

"How Chrome DevTools does it" was not my answer to the question, it was just the preamble. As mentioned, I much prefer to have caching disabled while I'm building or debugging sites (specifically: because I'm often changing the markup or the css or the javascript, and I want my most recent change to come through to the browser upon reload).

Disabling the cache by default can be troublesome. I'd say it breaks the principle of least surprise - I wasn't aware of this behavior in Chrome, and it's a good thing I develop with Firefox, as I just resolved a bug that only manifested itself when bypassing the browser cache. If the browser cache had been linked to dev tools being open in my case, I probably would have ended up down some false causality rathole around dev tools.

We implemented it that way so that we wouldn't have a never ending list of "the browser is slow when devtools are open" bugs.

We do plan on making the disable cache toggle more visible (probably with the other buttons at the top of the main panel) and making it very obvious that the cache is disabled.

When we have done that it would make sense to have the button remember state.

I'm actually surprised developers using Firefox don't use firebug? It's great that Mozilla are improving the native tools but they are a long way from a moving goal post that is Firebug.

I wish I could get a reference from the console command line to an object I printed in the console earlier.

For example: in my code I write console.log({ foo: function(msg) {...} }). The object is displayed as "[object Object]" (which isn't as good as Chrome's output by the way) and, sure, I can click it to inspect it,but what I'd like is, like, right-click->"Copy reference" and then it puts "$_(123)" in my clipboard, where $_ is a console-defined function which takes a number and returns the matching output of the console history.

Then I can use the referenced object in a new command: e.g. $_(123).foo('hello').

Firebug has $_ [1] but it's just for the last output of the command line (not the console history). (edit: likewise for Chrome [2])

Thank you for the many enhancements.

[1]: https://getfirebug.com/wiki/index.php/Command_Line_API#.24

[2]: https://developers.google.com/chrome-developer-tools/docs/co...

I love the look of the font preview. One of my major gripes with web fonts and listing multiple sources is not knowing which font rule is actually applying. Looks like this might solve my problem.

Live editing JS and recompile doesn't seem to be possible from devtools. My experience with scratchpad doesn't do that so I have to fall back to Chrome when I want to edit JS loaded by the page on a third-party site. Is that still true?

You can use Cmd+E to re-evaluate individual functions: http://fitzgeraldnick.com/weblog/52/

As far as full live editing goes, we have some refactoring and infrastructure work that needs to happen first that also blocks things like properly debugging eval'd strings and dynamically appended scripts. Its pretty high on our priority list and should be coming soonish!

Yeah. Thanks. Until then I can't :/ do you have the bug number?

https://bugzilla.mozilla.org/show_bug.cgi?id=771339

The box model highlighter looks great. This was the only reason keeping me from switching from firebug to dev tools entirely. Also, the other improvements are great news as well. Good job!

Very cool, I like the Console to Inspector hookup that they added!

I thought you were referring to a way to connect my terminal to the browsers console.

I would love for there to be some node.js plugin where I could basically connect to the browser's js console.

You're looking for something like https://github.com/harthur/fxconsole

Interesting they've added option to hide buttons, but kept huge icons on tabs, chrome used to have similar ugly icons, but fortunately they are removed now.

Is there about:config option to disable grouping of console.* messages like in firebug? Otherwise I lose their order, which is not helpful.