Requested feature overview description.
Allow user supplied HTML as valid content, so HTML5-based non-flash animations can be uploaded. I uploaded an example for a very basic animation with interactivity to https://mega.nz/#!FL4jEIQD!ASQcXbtwJOXOp45NWoI7CTczlLRby-1kf_j8tp7fApc .

Why would it be useful?
HTML5 animations work on all modern browsers and operating systems, including mobile devices, even those which are not supported by Adobe Flash.

What part(s) of the site page(s) are affected?
Backend would need to recognize the user-supplied HTML-file as allowed file type. For security reasons, the front-end would need to display this content in a sandboxed iframe (see https://caniuse.com/#feat=iframe-sandbox ).

I would like to see a world where one does not need Adobe Flash for sharing interactive content. Let me know what you think.

EDIT: Uploaded tech-demo to mega and ajdusted the link.

Security and feasibility aside. I'm curious if there is even any furry-related html5 content. I mean, it's not like it will change what artists write their stuff in (afaik none of the well-known furry site allows uploads like this). So where would users even get content from?

Does HTML even support iframes anymore? I thought they were deprecated shortly before HTML5 and declared obsolete when HTML5 started being more widely used.

kamimatsu said:
Does HTML even support iframes anymore? I thought they were deprecated shortly before HTML5 and declared obsolete when HTML5 started being more widely used.

They support iframes, it's just heavily discouraged because it's hard to make them secure and not screw with usability (and so many web devs failed at this that they generally give people a bad taste in their mouths). I think they did deprecate some functions though.

fully support this notion. Flash should go into a ditch and stay there.

parasprite said:
Security and feasibility aside. I'm curious if there is even any furry-related html5 content. I mean, it's not like it will change what artists write their stuff in (afaik none of the well-known furry site allows uploads like this).

i don't remember, what was Alder's Fall of Eden game mads with?

treos said:
i don't remember, what was Alder's Fall of Eden game mads with?

Apparently javascript with bits of HTML and CSS.

parasprite said:
(...) I'm curious if there is even any furry-related html5 content. (...) none of the well-known furry site allows uploads like this (...)

This illustrates kind of an chicken-and-egg-problem: As long as no site accepts non-flash animations, all creators are forced to stick with flash. Many (e.g. fewrahuxo) do not like Flash. It might be a good idea to allow alternatives.

kamimatsu said:
Does HTML even support iframes anymore? I thought they were deprecated shortly before HTML5 and declared obsolete when HTML5 started being more widely used.

iframes were changed drastically from HTML 4 to HTML5 (confer https://www.w3schools.com/tags/tag_iframe.asp ). The new sandbox attributes are specifically engineered towards rendering external or user generated content safe (see https://www.html5rocks.com/en/tutorials/security/sandboxed-iframes/#play-in-your-sandbox ). In theory, sandboxed content in an iframe has the same level of security as a flash animation.

parasprite said:
[Fall of Eden is] apparently javascript with bits of HTML and CSS.

Yes, that is what HTML5 "apps" look like. There actually is a project porting fenoxo's well known "Corruption of Champions" to HTML5 (see https://github.com/Kitteh6660/Corruption-of-Champions-HTML ) so it can be played on iPhones.

parasprite said:
Apparently javascript with bits of HTML and CSS.

Slowdown said:
Yes, that is what HTML5 "apps" look like. There actually is a project porting fenoxo's well known "Corruption of Champions" to HTML5 (see https://github.com/Kitteh6660/Corruption-of-Champions-HTML ) so it can be played on iPhones.

huh, interesting.

the COC project appears dead considering the last update was in June 2016, and not being released under a permissive license, nobody can fork it.

As much as I would love this, securing it would be hard, we'd need to have another domain name to secure it.

In the future, we could look for code that can strip the security problems from HTML5 or SVG. But it's a lot of work for not much gain to add support for this.

Blah.. HTML5 sucks for things such as games and the like. I still can't understand what made them think that rich content would be a good idea for something like HTML to deal with in the first place. It's called "HyperText Markup Language" not "Rich Content Container Format". :/

Lance_Armstrong said:
In the future, we could look for code that can strip the security problems from HTML5 or SVG. But it's a lot of work for not much gain to add support for this.

I fully agree that automatic server-side code audits are not feasible.
I might be too enthusiastic about sandboxed iframe and maybe I fail to see the "security problems from HTML5 or SVG".

Chaser said:
As much as I would love this, securing it would be hard, we'd need to have another domain name to secure it.

Indeed, a second domain name would be necessary to prevent user-generated content to interfere with the rest of e621.

I appreciate both of you looked into this request.

I personally disagree that HTML5 sucks for interactive creations. Personally, I would make use of a feature like HTML5 support almost all the time if it were widely available, because it's a lot more convenient than Flash for me to create things for. Actionscript is a language I like a lot less than Javascript.

Whether or not it's a "good idea" (and I do think it's a good idea), the support for it is there. All that remains is for people running websites like these to allow users to tap into that potential. Whether or not that's desirable or feasible is what we are discussing here. Personally I think it's highly desirable.

The real problem is that other art websites do not yet support HTML5. As Slowdown said, it's the chicken-and-egg-problem. I'm not sure e621 is a website that would benefit from being the first one to take that step, seeing as almost all artists primarily create their art for showcasing it on other websites primarily, and only submit them here (or have others submit them) as an afterthought. That's why, for now, I agree with Lance, as much as it pains me to have to say no.

E: If it turns out that there are indeed no security or practicality concerns, please do implement this. It would be an awesome feature.

Kemono-Kay said:
The real problem is that other art websites do not yet support HTML5. As Slowdown said, it's the chicken-and-egg-problem. I'm not sure e621 is a website that would benefit from being the first one to take that step, seeing as almost all artists primarily create their art for showcasing it on other websites primarily, and only submit them here (or have others submit them) as an afterthought. That's why, for now, I agree with Lance, as much as it pains me to have to say no.

Pretty much this. Other sites allow animated and interactive content basically either GIF or Flash. Now if we boil this down, flash is insanely commonly used to simply contain video file, so as we already have WebM support, this already is better option for those doing animations like this which they earlier needed to convert into gif or flash video inside flash.

So what the HTML5 "animation support" would do is it would essentially replace the flash requirement, in other words those doing interactive content. So, as almost no other site supports anything else than flash for this, at least at this point the benefits of having such support are pretty low.

Not opposing the idea at all, but artists still seem to be unable to create WebM content which makes them rely on flash and gif, so I would imagine them creating HTML5 content would be even bigger obstacle.

Sorry to dig up a two year old thread, but what is the status on this support? We're now less than 2 years away from Flash support being removed from Chrome and a little more than a year for Firefox. There isn't a lot of time left to offer up something else as an alternative in the mean time.

Plus in a couple months I'll actually have something I'll personally want to upload and it'd be nice if I could upload to hear (and not just Newgrounds).

TisFoolish said:
Sorry to dig up a two year old thread, but what is the status on this support? (…)

Coss-linking to this post. The admins looked into the matter. HTML5 is more restrictive when it comes to storing data client-side (e.g. savegame) than Flash. Interactive content would compete for storage space. It would not work in the long run, so no support is planned.