Webpage loaded but not showing

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jaymel

Webpage loaded but not showing

Unread post by jaymel » 2018-07-14, 09:25

Mint 17.3x64 PM 27.9.3

This is very infrequent PM behaviour and similar to previously reported problems with a webpage showing a completely blank display. The webpage this time is https://grand-cafe.co.uk/. The title of the page and Pale Moon displays accurately. The page displays without problem in Qupzilla (1.6.0). I do not have a javascript blocker active. So far I've tried clearing the cache, running PM in safe mode, turning off uBlock Origin, and even flipping plugins.rewrite_youtube_embeds to false (viewtopic.php?f=3&t=15607&p=113120&hili ... nk#p113074).

From the size and appearance of the vertical scroll bar, the whole page is there but not displaying. If I use Ctrl-u to look at the source, there are around 2400 lines of code. If I copy all the code and paste it into a text editor (gedit), I can save it to the desktop as a text file. I can open that text file, either again in gedit, or I can open it in Pale Moon. When I do the latter, the webpage opens! The webpage is there, mainly, but not exactly, as it shows in Qupzilla (some position and size differences).

I posted this problem in a newsgroup and asked if the webpage displayed in their browser.
Blank page:
Win7 PM 27.9.3
Fx 45.2.0 ESR
FX 38.8 ESR

Displays OK:
IE
Fx 52.1.2 ESR
(and Qupzilla 1.6.0)

Any ideas why the page is "there" but doesn't show? Why does PM not load the page from the internet URL, but apparently does it from the same code in a desktop file?

Thanks in advance for any advice.

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Moonchild
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Re: Webpage loaded but not showing

Unread post by Moonchild » 2018-07-14, 09:42

Whatever tool is used to create the pages sets the opacity of elements to 0 by default (so it's there but not visible) and then relies on JavaScript to "fade everything in" in an attempt to be cool. That's all nice and good unless your JS doesn't work on browsers and aborts with an error before the "fade in" happens, leaving visitors staring at a blank page.
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therube
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Re: Webpage loaded but not showing

Unread post by therube » 2018-07-14, 13:49

webpage showing a completely blank display
FWIW, FF 38 does likewise.

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badnick
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Re: Webpage loaded but not showing

Unread post by badnick » 2018-07-14, 14:04

Work's well on PM -unstable but not so well on Firefox 61
Windows 10 pro /64 (version 1809)
PM last/64

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therube
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Re: Webpage loaded but not showing

Unread post by therube » 2018-07-14, 14:15

Works fine in FF61.
Do you have something blocking in FF61?

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Re: Webpage loaded but not showing

Unread post by badnick » 2018-07-16, 11:40

therube wrote:Works fine in FF61.
Do you have something blocking in FF61?
Yes it was about blockers.
Windows 10 pro /64 (version 1809)
PM last/64

jaymel

Re: Webpage loaded but not showing

Unread post by jaymel » 2018-07-19, 07:57

Moonchild wrote:Whatever tool is used to create the pages sets the opacity of elements to 0 by default (so it's there but not visible) and then relies on JavaScript to "fade everything in" in an attempt to be cool. That's all nice and good unless your JS doesn't work on browsers and aborts with an error before the "fade in" happens, leaving visitors staring at a blank page.
Sorry for the delayed reply but I had emailed the website developers hoping for a comment, but no response so far.

Thanks for the explanation regarding opacity, but I don't understand the comment "...unless your JS doesn't work on browsers...". What JS are we referring to here? Other browsers do display the webpage, and PM does display a fair amount of the page from a saved file. Is more than one sort of JS involved?

TIA

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Re: Webpage loaded but not showing

Unread post by Moonchild » 2018-07-19, 08:11

JS has become an incredibly large specification, and because of the way it works, it is very intolerant to errors. Any error will abort a current function, so if there's a problem with the function that is supposed to fade in the elements by using something Pale Moon doesn't (yet) have, it will render the page but never show anything. So there aren't different kinds of JS, but there are many different ways of doing things, some more browser-tolerant than others. it's complicated even more by the fact different year specifications (versions of ECMAScript) of JS are incompatible with themselves. Something may be valid in ES5 but not ES6, or the other way around. That means that any website that heavily uses JS must cater to both versions to be browser-agnostic, but often they aren't.
Last edited by Moonchild on 2018-07-19, 08:14, edited 1 time in total.
"Sometimes, the best way to get what you want is to be a good person." -- Louis Rossmann
"Seek wisdom, not knowledge. Knowledge is of the past; wisdom is of the future." -- Native American proverb
"Linux makes everything difficult." -- Lyceus Anubite

jaymel

Re: Webpage loaded but not showing

Unread post by jaymel » 2018-07-19, 09:29

Moonchild wrote:JS has become an incredibly large specification, and because of the way it works, it is very intolerant to errors. Any error will abort a current function, so if there's a problem with the function that is supposed to fade in the elements by using something Pale Moon doesn't (yet) have, it will render the page but never show anything. So there aren't different kinds of JS, but there are many different ways of doing things, some more browser-tolerant than others. it's complicated even more by the fact different year specifications (versions of ECMAScript) of JS are incompatible with themselves. Something may be valid in ES5 but not ES6, or the other way around. That means that any website that heavily uses JS must cater to both versions to be browser-agnostic, but often they aren't.
Quick and clear explanation. Thank you.

jaymel

surveyor 7

Re: Webpage loaded but not showing

Unread post by surveyor 7 » 2018-07-19, 20:44

A workaround for this site and many others is to set View->Page Style->No Style for the tab, which often gives an ugly but readable version of the page.

Of course, if you want to visit the site often or do much interaction with it, this may not be a suitable approach, but for one visit it is more readable than either a blank page or the page source.

jaymel

Re: Webpage loaded but not showing

Unread post by jaymel » 2018-07-20, 07:11

surveyor 7 wrote:A workaround for this site and many others is to set View->Page Style->No Style for the tab, which often gives an ugly but readable version of the page.

Of course, if you want to visit the site often or do much interaction with it, this may not be a suitable approach, but for one visit it is more readable than either a blank page or the page source.
Yes, I'd discovered the "No Style" partial fix. It gives, as far as I can tell, the same webpage display as opening the source code text file in PM that I mentioned in my original message. Much more usable than the code page as you say, but it is still possible that something isn't displaying and you wouldn't know what it was! And, as the sub-pages displayed, the info I needed was there.

Anyway, it's definitely a JS issue. I just got a reply from the website designers: "it looks to be a javascript bug which occurs with one of the Firefox releases, I’ve not been able to test on the Pale Moon browser (unfortunately its not available in our testing suite browserstack.com) but we will add it to a list of things to address."

Jaymel

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