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The fact that browsers accept defective html is the most evil thing that happened to the web. Any library that tries to parse "real world" html just contributes

The fact that browsers accept defective html is the most evil thing that happened to the web. Any library that tries to parse "real world" html just contributes to that evil. I am astonished that we tolerate this and still call ourselves (software) engineers.

donut 15y ago
"Be liberal in what you accept, and conservative in what you send." - http://en.wikipedia.org/wiki/Robustness_principle http://en.wikipedia.org/wiki/Robustness_principle
- perfunctory 15y ago
  http://queue.acm.org/detail.cfm?id=1999945 http://queue.acm.org/detail.cfm?id=1999945
  - donut 15y ago
    Good read, thanks for that. I agree with the conclusion: there is no one-size-fits-all rule for interoperability. The way I see it, it's ultimately about tradeoffs. I can only imagine what things would be like today if web browsers implemented a strict parsing of HTML and refused to render invalid pages. One possibility is hindered adoption of HTML by the masses. Another is that two vendors would disagree about the HTML spec and cause pages to be browser-specific. (Turns out this happened anyway :-)) Is the HTML5 spec better in terms of interop and compatibility than the previous ones? http://www.tbray.org/ongoing/When/201x/2010/02/15/HTML5 http://www.tbray.org/ongoing/When/201x/2010/02/15/HTML5
olavk 15y ago
There are pages on the web which will never be updated because the author is dead. Browsers have to be able to render what is out there. You could argue that we would have been better off new if all browsers from day one had only rendered valid html, but you need a time machine to fix that.
- perfunctory 15y ago
  This problem can trivially be solved by introducing a new doctype. <!doctype newhtml> - strict parsing, otherwise sloppy parsing. I honestly don't understand why the web community doesn't adopt it.
  - olavk 15y ago
    It doesn't solve any problem, since the invalid html will still be in the wild and you still need to parse it. You just introduce a new parsing mode without graceful recovery. Some authors might use the newhtml doctype (because they have read somewhere it is better) but only test in a browser which dont support newhtml mode, so they still don't discover that the html is invalid. So we are back to square one.
  - derobert 15y ago
    Ummm, that already exists. That's how XHTML (delivered as XML) works. Make a syntax error in the page? Browser gives up, displays an error. It didn't catch on. The various HTML strict modes turn off "quirks" mode as well.
AndrewDucker 15y ago
As engineers our job is to make it easy for people to do things. Being tolerant of ordinary people's mistakes makes it possible for non-engineers to make web pages, and that's a good thing.
- perfunctory 15y ago
  Show me a non engineer who creates web-pages by writing raw html. And even if they did, wouldn't they be better off if the browser gave them helpful error messages to help them fix their html, rather than just silently rendering nonsense.

donut 15y ago

"Be liberal in what you accept, and conservative in what you send." - http://en.wikipedia.org/wiki/Robustness_principle http://en.wikipedia.org/wiki/Robustness_principle

perfunctory 15y ago
http://queue.acm.org/detail.cfm?id=1999945 http://queue.acm.org/detail.cfm?id=1999945
- donut 15y ago
  Good read, thanks for that. I agree with the conclusion: there is no one-size-fits-all rule for interoperability. The way I see it, it's ultimately about tradeoffs. I can only imagine what things would be like today if web browsers implemented a strict parsing of HTML and refused to render invalid pages. One possibility is hindered adoption of HTML by the masses. Another is that two vendors would disagree about the HTML spec and cause pages to be browser-specific. (Turns out this happened anyway :-)) Is the HTML5 spec better in terms of interop and compatibility than the previous ones? http://www.tbray.org/ongoing/When/201x/2010/02/15/HTML5 http://www.tbray.org/ongoing/When/201x/2010/02/15/HTML5

olavk 15y ago

There are pages on the web which will never be updated because the author is dead. Browsers have to be able to render what is out there. You could argue that we would have been better off new if all browsers from day one had only rendered valid html, but you need a time machine to fix that.

perfunctory 15y ago
This problem can trivially be solved by introducing a new doctype. <!doctype newhtml> - strict parsing, otherwise sloppy parsing. I honestly don't understand why the web community doesn't adopt it.
- olavk 15y ago
  It doesn't solve any problem, since the invalid html will still be in the wild and you still need to parse it. You just introduce a new parsing mode without graceful recovery. Some authors might use the newhtml doctype (because they have read somewhere it is better) but only test in a browser which dont support newhtml mode, so they still don't discover that the html is invalid. So we are back to square one.
- derobert 15y ago
  Ummm, that already exists. That's how XHTML (delivered as XML) works. Make a syntax error in the page? Browser gives up, displays an error. It didn't catch on. The various HTML strict modes turn off "quirks" mode as well.

AndrewDucker 15y ago

As engineers our job is to make it easy for people to do things. Being tolerant of ordinary people's mistakes makes it possible for non-engineers to make web pages, and that's a good thing.

perfunctory 15y ago
Show me a non engineer who creates web-pages by writing raw html. And even if they did, wouldn't they be better off if the browser gave them helpful error messages to help them fix their html, rather than just silently rendering nonsense.