Introduction to HTML (Part 2)

1. Add the javascript below into the head tag under our meta tags.

This is only for the purposes of showing the canvas in action.

            

<script type="text/javascript">
			window.onload = function(){
				var c = document.getElementById("jbc");
				var ctx = c.getContext("2d");
				ctx.fillStyle = "#FF0000";
				ctx.fillRect(0,0,150,75);
			}
</script>

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This tells the browser to make the drawing 2d after searching the document by Id for the
canvas when the window loads. Then to fill in the canvas with red to a certain point.

2. Replace the existing content with an audio tag, video tag and canvas tag.

These tags are shown in the following steps. Any line that begins with "<!--" is an html comment to document code for future reference.

3. Insert an audio tag.

This sets the controls shown, define the source, and sets the error message if we can not support either format.

<!--this is an html comment for documenting your css and html-->
				<!--this is an audio element-->
					<audio controls="controls">
						<!--this will show the mp3 version of an audio-->
						<source src="#.mp3" type="audio/mp3">
						<!--this will show the ogg version of an audio-->
						<source src="#.ogg" type="audio/ogg">
						audio tag not supported
					</audio><BR>

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4. Insert a video tag.

This sets the controls shown, defines the source, and sets the error message if we can not support either format.

<video controls="controls" width="640" height="480">
						<!--this will show the ogg version of an video-->
						<source src="#.ogg" type="video/ogg">
						VIdeo tag not supported
						<!--this will show the mp4 version of an video-->
						<source src="#.mp4" type="video/mp4">
</video><BR>

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5. Create the canvas element based on the javascript found above.

Set the id to jbc. Set the width and height as well as a small bit of css so you can see where the canvas is on the template. Then close out the canvas tag and load the page.

<canvas id="jbc" width="200" height="100" style="border: 1px solid #000000;"></canvas>

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