Ensuring cross-browser structure
Video: Ensuring cross-browser structureOur HTML5 layout is now complete. We've tested it in all our browser. We've checked the outline. Everything is good, right? Well, almost. Although most modern browsers handle the new HTML5 semantic elements just fine, and Internet Explorer 9 is supposed to have great HTML5 support, older versions of browsers, most notably Internet Explorer, can have some serious problems rendering your shiny new HTML5 document. So let's take a moment to deal with that before we move on to our next chapter.
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In HTML5 First Look, author James Williamson introduces the newest HTML specification, providing a high-level overview of HTML5 in its current state, how it differs from HTML 4, the current level of support in various browsers and mobile devices, and how the specification might evolve in the future. Exercise files accompany the course.
- Understanding the history of HTML5
- Using new tags
- Understanding HTML5 semantics
- Coding ID and class attributes in HTML5
- Structuring documents
- Building forms
- Exploring HTML5 native APIs
- Encoding and adding HTML5 video
- Exploring associated technologies such as CSS3
Ensuring cross-browser structure
Our HTML5 layout is now complete. We've tested it in all our browser. We've checked the outline. Everything is good, right? Well, almost. Although most modern browsers handle the new HTML5 semantic elements just fine, and Internet Explorer 9 is supposed to have great HTML5 support, older versions of browsers, most notably Internet Explorer, can have some serious problems rendering your shiny new HTML5 document. So let's take a moment to deal with that before we move on to our next chapter.
So I have the trails.htm file opened and I'll go ahead and open up the main.css file from the _css 04_06 folder as well. So we're working in the 04_06 folder. We need the trails opened and we're going to open up the main.css from the _css folder. We're going to take here of the styles first. There are a few things that we need to do stylistically to make sure that these elements are going to render properly in our browsers. So I'm going to switch over to my CSS file and I'm just going to scroll down a little bit until I get right above the main body selector which is on around line 34 or so.
So the same way that you've probably gotten used to doing a CSS reset for all of your documents. When you start working with HTML5, you're going to probably get used to doing this sort of HTML5 display rule grouping. So basically what we're going to do is we're going to take all the sectioning content and some of the flow content elements and we're going to tell browsers to represent them as display objects. So display them as block model objects basically. Now we're doing this for a couple of reasons. Number one, again Internet Explorer doesn't even recognize these tags.
It doesn't even know what they are, so it certainly doesn't know how it should go about rendering them. That's also a problem with some of our older browsers as well. Plus the HTML5 specification doesn't say how these elements should be displayed, whether they're block or in-line elements. Now, the majority of devices and browsers out there will display them as block level elements, but we call this covering our bases. So what I'm going to do is I'm just going to do html5 display rule. I'm just going to remind myself that that's what this is and I'm going to comment that out.
So I'm just going to add a comment above the selector that I'm about to create. Now, we're going to create a fairly long group selector, so just stay with me on this. So first we're going to do article, aside, canvas, details, figcaption, figure, footer, header, hgroup, menu, nav, section, and then summary.
Go ahead and open up a curly brace, hit Return and the only property we need here is display and we're going display that as a block level element. Then you can go ahead and close your curly brace and the rule's get on there. So there are a lot of elements here. Some of them we've used, some of them we haven't, but these are all elements that should display as block level elements within your browser. Some of these elements, like details and fig caption, aren't even supported yet, even by the most modern browsers. Or they aren't supported at least as of the time of this recording, but we are putting them in there so that we can be forward compatible, so that we get used to doing this rule, if you save it as a snippet, copy and paste it, as browser support matures and you begin using those tags, you don't have to worry about remembering to add them to whatever display rule you've got within your CSS.
Okay, so we're going to go ahead and save that. And now at least we have something telling these browsers and devices that these elements should display as block level elements. But what about a browser like Internet Explorer, who doesn't even understand what those elements are and don't allow for those elements to have existed at all? So Internet Explorer, at least older versions, would really break with our current layout. So, let's take a look at a way we can deal with that. I'm going to switch over and go out to the Google Code web site because I want to show you something that's out there. Okay, so here I'm at code.google.com/p/html5shiv.
So what in the world is this? Well, again Internet Explorer does not recognize those elements that we just set the display property to block on, so our layout would not work in those older versions of Internet Explorer. Well, what this does is that just three lines of code that runs a conditional comment and then if the browser is Internet Explorer less than version 9, it's going to go ahead and run this script which is hosted at Google. All this script really does is create those elements. So it doesn't place them on the page. It just sort of creates them and hangs them up in the ether, so that Internet Explorer goes, "Oh! okay, so those elements do exist.
This is the minified version of the code. I believe it was written by Remy Sharp. If Remy didn't write this, I apologize to whoever did, but again there are a lot of regular expressions going on here, but the code itself really isn't that difficult. All it's really doing is creating those elements for you. So a faster and easier way to use this perhaps is to just go ahead and copy and paste this into your code and that is what we are going to do. So I'm going to go ahead and highlight these blocks of code right here, so the conditional comment that surrounds it and the script tag. I'm going to copy it and then I'm just going to go back into my HTML editor.
Okay, so I'm back in my trails.htm file. What I want to do is find the closing head tag, which is right here on line seven for me, and I'm just going to create a blank line and paste that code right above the closing head tag. So if I save this, we're now good to go and earlier versions of Internet Explorer will recognize and display those block level elements correctly. So our page is now well and truly finished. We're using HTML5 structural elements and have added new meaning to our content through the use of our semantic markup.
By adding just a few lines of code to our CSS and by adding this quick scripting fix for older versions of Internet Explorer, our HTML5 layout is now a cross-browser compliant as well as semantically rich.
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