Loading Additional Content

If you want to reuse this preloader to load additional content once the user is in the site, all you have to do is make sure the preloader movie clip, or another preloader clip also registered to the Preloader class, is on the Timeline, and call the startLoad method with the parameter being the movie clip that the new movie will be loaded into.

Loading Multiple Files as Part of the Initial Load

For most of the sites that I build, it is necessary to load multiple files as part of the initial site load. This makes things a little bit trickier. The Preloader class could be extended by modifying the checkLoadProgress method so that it can accommodate multiple files.

When checking the load of multiple files, it is not a good idea to get a grand total by adding the result of getBytesTotal and getBytesTotal on all of the clips being loaded. I have noticed that Flash will only load three or four external files at once, and the getBytesTotal method will not return the proper value until a clip has started loading. For example, if you are loading five SWF files at once, and try to get a total bytes value in this way, you will only get the totals for the first three that start loading. As soon as one finishes, another will start loading, making your total value change, which will change the result of the percent loaded calculation. You will end up with an inaccurate loading animation.

Here are a couple of options for showing progress of multiple file loads:

• Have a separate progress animation for each file.

  The preloader that I built for the Spy Kids 3D site uses this approach. There is a stack of loading bars, each labeled according to what data the file contains. The loading is complete when all bars have been filled. If you are on a slower connection, this will also illustrate what I mentioned earlier about when files are loaded. You might notice that some of the bars are completely full before others begin to move.

• Hard code the total bytes of the files.

  The total bytes could be passed to the preloader when startLoad is called, and the loaded bytes would still be retrieved with getBytesLoaded called on each of the clips being loaded. This results in smooth and accurate preloader behavior. However, the drawback is that you have to update the total bytes value in the code every time any of the files is changed.

• The progress animation could be based on how many files have loaded. Instead of showing the percentage of bytes loaded, the animation could show the percentage of files loaded.

You will have to experiment with these methods and decide which works best for your situation.

Page 5 of 5

Previous Page