Using the LoadVars Class to Load Variables

The LoadVars class has three different methods: LoadVars.load, LoadVars.send and LoadVars.sendAndLoad. Basically, the load method loads variables from an external file or script, while the send method sends Flash variables to a remote script. The final method, sendAndLoad, is a combination of the first two methods. It sends variables from Flash to a server-side script and then waits for a response. This can be very useful if you need to send a user’s information to a script and then display a message depending on if the information was valid or not. For example, you may have built a simple login form where the user types in their username and password to gain access t o your site. If the username and password matched values in the database, you could do a gotoAndPlay(“welcome”) to let them enter the site. If the username and password didn’t match, you may want to display a message prompting them to try again, or else click on the register link to sign up for an account. Likewise, if you were building a game, you may want to send the user’s score to a server-side script wherich would insert the score into a table. If the user ranked within the top 20 scores you could forward them to a congratulations page.

You can see a brief example of the load method below, along with an event handler for the onLoad event, which gets triggered after the data has finished loading.

1. var myLoadVars_lv:LoadVars = new LoadVars();
2. myLoadVars_lv.load(“params.txt”, myLoadVars_lv);
3. myLoadVars_lv.onLoad = function(success:Boolean) {
4.     if (success) {
5.         trace(“myLoadVars_lv loaded:”);
6.         for (i in myLoadVars_lv) {
7.             trace(” myLoadVars_lv.”+i+” = “+myLoadVars_lv[i]);
8.         }
9.     }
10. };