Doctype And Older Versions Of HTML

ecchi · 2016-02-09, 05:51 AM

Can anyone explain why this works?

I used an online service to create a slideshow for my site. It worked on my Vista box, but on my XP box it only worked in Chrome, not in IE8. So I assumed it was in HTML5.

Today I was playing with the code with a view to (a) using it on other sites, and (b) making a version that worked on all browsers. I discovered the slider was entirely Javascript, so should work on IE8. Buggering about with it, I found that adding a doctype tag (doctype html) made it work. Why should this be? Why when everything else appears to work 100% OK without a declaration of doctype, should one Javascript piece of code require a doctype declaration?

Cleo · 2016-02-09, 09:26 AM

Doc type tells the engine in the browser how it should interpret the page.

ecchi · 2016-02-09, 05:24 PM

Yeah, sorry I wasn't clear. My question was "In that IE8 automatically assumes anything with a .html extension is a HTML document, why does it ignore certain javascript commands unless it is told the item is a HTML document in the document, by the doctype statement?"

Cleo · 2016-02-09, 05:36 PM

Because there is more than one kind of html doc and the doctype tells it what kind it is and what t do with its code.

The doctype control parsing of the page in order to display it correctly.
http://www.w3.org/QA/2002/04/valid-dtd-list.html

ecchi · 2016-02-10, 05:16 AM

Yes but without the declaration it processes most Javascript perfectly, so why not all Javascript? Also the declaration I am making does not tell it what version of HTML I'm using, I simply added:

Code:

<!DOCTYPE html>

Which basically says "I'm using some kind of html, but I'm not going to tell you what version - work it out for yourself", which the browser already knew from the .html file extension.

ecchi · 2016-02-15, 04:54 PM

I was given the answer over the weekend. If anyone wants to know:

It was not the Javascript, it was "div id=" which was the problem. Apparently IE8 knows some HTML commands that were not instigated when it was created, but had been mooted. If it is not fed a HTML type, it sticks strictly to the HTML that was official when it was released (which I think was HTML 3). However it takes "!DOCTYPE html" to mean "follow all HTML notification you know" so using this gets it to accept a few later HTML commands.

2016-02-09, 05:51 AM	#1
ecchi Banned Join Date: Oct 2003 Location: About to be evicted!!!! Posts: 4,082	Doctype And Older Versions Of HTML Can anyone explain why this works? I used an online service to create a slideshow for my site. It worked on my Vista box, but on my XP box it only worked in Chrome, not in IE8. So I assumed it was in HTML5. Today I was playing with the code with a view to (a) using it on other sites, and (b) making a version that worked on all browsers. I discovered the slider was entirely Javascript, so *should* work on IE8. Buggering about with it, I found that adding a doctype tag (doctype html) made it work. Why should this be? Why when everything else appears to work 100% OK without a declaration of doctype, should one Javascript piece of code require a doctype declaration?

2016-02-09, 09:26 AM	#2
Cleo Subversive filth of the hedonistic decadent West Join Date: Mar 2003 Location: Southeast Florida Posts: 27,936	Doc type tells the engine in the browser how it should interpret the page. __________________ Free Rides on Uber and Lyft Uber Car: uberTzTerri Lyft Car: TZ896289

2016-02-09, 05:36 PM	#4
Cleo Subversive filth of the hedonistic decadent West Join Date: Mar 2003 Location: Southeast Florida Posts: 27,936	Because there is more than one kind of html doc and the doctype tells it what kind it is and what t do with its code. The doctype control parsing of the page in order to display it correctly. http://www.w3.org/QA/2002/04/valid-dtd-list.html __________________ Free Rides on Uber and Lyft Uber Car: uberTzTerri Lyft Car: TZ896289

2016-02-10, 05:16 AM	#5
ecchi Banned Join Date: Oct 2003 Location: About to be evicted!!!! Posts: 4,082	Yes but without the declaration it processes most Javascript perfectly, so why not all Javascript? Also the declaration I am making does not tell it what version of HTML I'm using, I simply added: Code: <!DOCTYPE html> Which basically says "I'm using some kind of html, but I'm not going to tell you what version - work it out for yourself", which the browser already knew from the .html file extension.

2016-02-09, 05:24 PM	#3
ecchi Banned Join Date: Oct 2003 Location: About to be evicted!!!! Posts: 4,082	Yeah, sorry I wasn't clear. My question was "In that IE8 automatically assumes anything with a .html extension is a HTML document, why does it ignore certain javascript commands unless it is told the item is a HTML document in the document, by the doctype statement?"

2016-02-15, 04:54 PM	#6
ecchi Banned Join Date: Oct 2003 Location: About to be evicted!!!! Posts: 4,082	I was given the answer over the weekend. If anyone wants to know: It was not the Javascript, it was "div id=" which was the problem. Apparently IE8 knows some HTML commands that were not instigated when it was created, but had been mooted. If it is not fed a HTML type, it sticks strictly to the HTML that was official when it was released (which I think was HTML 3). However it takes "!DOCTYPE html" to mean "follow all HTML notification you know" so using this gets it to accept a few later HTML commands.