Specifications

CHAPTER 10
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About failover
The failover feature is used for two reasons:
• If the Flash Player is not at least version 9.0.115 and it tries to load a signed RSL, it will attempt to load the
failover RSL
• If a network or server failure occurs while loading the main RSL, Flash Player will attempt to load the failover
RSL
For framework RSLs, you typically specify a signed RSL as the main RSL, and an unsigned RSL as the failover RSL.
When loading an application that uses signed framework RSLs, older versions of Flash Player skip the signed RSL
and attempt to load the failover RSL, which is typically an unsigned RSL.
For all RSLs, the failover RSL provides a mechanism to load an RSL if the primary server is unavailable.
You can specify the location of the RSL and a failover RSL in your flex-config.xml file or on the command line as
parameters to the
runtime-shared-library-path option. The default failover RSL is
framework_3.0.${build.number}.swf. In Flex Builder, you can add failover RSLs by adding them to the
Deployment Paths in the Library Path Item Options dialog box.
Compiling applications with standard and cross-domain RSLs
Compiling your application with standard or cross-domain RSLs is easier to do in Flex Builder than it is on the
command line. Flex Builder can automatically extract the RSL SWF file for you during the compilation process,
and use that SWF to compile your application against. If you use the command-line compiler, then you must
extract this file from the SWC file yourself prior to deployment. In either case, when you deploy the RSL SWF file,
you should optimize it as described in “Optimizing RSL SWF files” on page 212.
Compile with standard or cross-domain RSLs in Flex Builder
1 Open your Flex application’s project.
2 Select Project > Properties.
3 Select Flex Build Path in the option list. The Flex Build Path settings appear.