3.2 Behind the Scenes

At this point let's take a step back and have a look at what is generated when a Web Page is compiled.

If the Web Page compiled successfully three files would be generated into your partition web directory \X_WIN95\X_LANSA\x_<partition>\web\vl :

The HTML file is what is kicked off in the browser when you executed the Web Page so let's open the HTML file in a text editor and have a look inside.

Don't panic at this point, you don't need to know anything about HTML to use web with Visual LANSA. We are just having a one off look inside to get a basic understanding of how it works.

First up, looking at the code between the <script></script> tags notice there is no static HTML to define your page but instead the generated code triggers the load of the LANSA runtime (lansa.js) and instructs it to show the page you just compiled. The LANSA runtime will subsequently load the JavaScript for your page (mywebpage.js) and runs the code that constructs the user interface.

The directory the LANSA runtime is loaded from, in this case /lansa_14_1_0_0, determines the version of the JavaScript runtime which is loaded.

A new version of the runtime will be supplied with major releases of LANSA. To take advantage of the latest runtime features you will need to recompile your Web Pages to regenerate the HTML so that is loads the latest runtime.

If you do not want to change your Web Application that is fine as longer as the corresponding version of the LANSA runtime is available to be loaded when executing your Web Page. That is, when you deploy your Web Application you will need to ensure all required runtime versions are installed.

In the following installation there are two versions of the JavaScript runtime:

What you see when you open the JavaScript file depends on the options selected when you compiled it. If you compile for Debug, you will see readable JavaScript as well as the original RDMLX (in comments) and you will recognize the corresponding JavaScript statements. If you compile for Release (that is not Debug enabled), you will see unreadable minified code instead. The code is minified because the end-product needs to be as small and fast as possible and you also probably don't want the end user to be able to read your logic.

Don't worry about the cache manifest file (mywebpage.appcache) at this point in time, other than to note this is a text file that lists the resources the browser should cache for offline access. We'll come back to this concept in 7. Offline Accessibility.