lecture 10: frames introduction

The previous slide discussed how you could get two different web pages to open up in separate windows on the screen. But how about opening two, or more, different web pages in the same window?

To do this you can use a technique known as frames. There are basically two kinds of frame: "ordinary" frames, which we will discuss first, and "inline" frames, which we will look at in a few slides' time. These use entirely different tags to set up, although some of the basic principles are the same.

The way ordinary frames work is that you first of all create what is known as a frameset document in which you define, first, how you want the window to be divided up. Then, you define which files you want to load up into each of the parts of this window. The best way to illustrate this is by this example: which will open in the second browser window. Have a quick look around this mini-site and note how different parts of the window update when you click on links: also have a look at the URL, which does not change. I will explain on following slides how all this works.

Before going on, though, it's worth mentioning that the status of frames has long been problematic in web design. WebAIM's advice on frames says that though frames are not inaccessible to special browsers, "they can be disorienting". But if you are careful, and adopt some basic accessibility principles, you can alleviate most of these problems. We will also talk about that side of frames in this lecture.