1358133 - Integrated JSON Viewer shows a blank page

Status: RESOLVED DUPLICATE of bug 1366239

(DevTools :: JSON Viewer, defect)

Description

[Anselmo Canfora]

User Agent: Mozilla/5.0 (Windows NT 6.3; Win64; x64; rv:53.0) Gecko/20100101 Firefox/53.0
Build ID: 20170413192749

Steps to reproduce:

Loaded a 52 KiB long page returning JSON content with application/json Content-Type header


Actual results:

Firefox displays a blank page when devtools.jsonview.enabled is true
going to page source with Ctrl + U displays the full json text
disabling devtools.jsonview.enabled and using an alternate add-on like JSONView or JSON Lite show correctly formatted JSON content


Expected results:

I expected to see formatted JSON like from add-ons JSONView or JSON Lite

Cannot attach the file for privacy reasons, but checked it as well-formed JSON with several tools.

reference: https://bugzilla.mozilla.org/show_bug.cgi?id=1243951#c21

Comment 1

[Oriol Brufau [:Oriol]]

I have also noticed this intermittently, sometimes the JSON Viewer fails to start, or you must wait A LOT until it shows the JSON. It does not seem to depend on the actual JSON contents. I blame react.js, I don't understand what's the point in using these libraries instead of fast native JavaScript.

Comment 2

[Anselmo Canfora]

(In reply to Oriol from comment #1)
> I have also noticed this intermittently, sometimes the JSON Viewer fails to
> start, or you must wait A LOT until it shows the JSON. It does not seem to
> depend on the actual JSON contents. I blame react.js, I don't understand
> what's the point in using these libraries instead of fast native JavaScript.

Are they really using a third party library for this? Mozilla? Seriously? I would be shocked to hear such a thing.

Comment 3

[Oriol Brufau [:Oriol]]

(In reply to Anselmo Canfora from comment #2)
> Are they really using a third party library for this? Mozilla? Seriously? I
> would be shocked to hear such a thing.

See for yourself:
resource://devtools/client/jsonview/viewer-config.js
resource://devtools/client/shared/vendor/react.js

Various devtools use react too, I suspect this is also the reason Inspector sometimes takes so much time to initialize.

Comment 4

[Anselmo Canfora]

(In reply to Oriol from comment #3)
> (In reply to Anselmo Canfora from comment #2)
> > Are they really using a third party library for this? Mozilla? Seriously? I
> > would be shocked to hear such a thing.
> 
> See for yourself:
> resource://devtools/client/jsonview/viewer-config.js
> resource://devtools/client/shared/vendor/react.js
> 
> Various devtools use react too, I suspect this is also the reason Inspector
> sometimes takes so much time to initialize.

Thanks for then info, I didn't figured this out. My opinion is that this is unacceptable, React of course isn't on par with native Javascript, and devtools should be as fast as possible.

http://stefankrause.net/js-frameworks-benchmark4/webdriver-ts/table.html

Comment 5

[Oriol Brufau [:Oriol]]

I just tried to load data:application/json,"a"
Only 3 characters. But the JSON Viewer failed with this error:

Error: Load timeout for modules: devtools/client/shared/vendor/react
http://requirejs.org/docs/errors.html#timeout
resource://devtools/client/jsonview/lib/require.js:166:17
Stack:
  makeError                          (resource://devtools/client/jsonview/lib/require.js:166:17)
  checkLoaded                        (resource://devtools/client/jsonview/lib/require.js:692:23)
  checkLoaded/checkLoadedTimeoutId<  (resource://devtools/client/jsonview/lib/require.js:713:25)

As I said in comment 1, this kind of things only occur from time to time, I cannot consistently reproduce.

Comment 6

[Oriol Brufau [:Oriol]]

Bug 1366239 mitigates this. Even if the JSON Viewer does not load, you should see the raw JSON text.

Comment 7

[Anselmo Canfora]

Best workaround is to set devtools.jsonview.enabled to false and install JSON Lite (performs better than JSONView:

https://addons.mozilla.org/en-US/firefox/addon/json-lite/?src=search

Comment 8

[Oriol Brufau [:Oriol]]

Closing as dupe of bug 1366239 because the JSON Viewer should no longer show a blank page. What sometimes happens is that it does not load and you only see the raw text, I filed bug 1424372 for this.