[FLEX-20816] Remove VERSION consts from all classes and replace them with compiler-generated version metadata on each class

• Type: Improvement
• Status: Closed
• Priority: Minor
• Resolution: Later
• Affects Version/s: Adobe Flex SDK Previous
• Component/s: Marshall Plan (Versioning)
• Environment: Affected OS(s): All OS Platforms; Affected OS(s): All OS Platforms; Language Found: English
• Assignee: Adobe JIRA
• Reporter: Adobe JIRA
• Created: 31/Aug/09 14:29
• Updated: 15/Apr/11 15:04
• Resolved: 16/Nov/09 12:33

Description

PARB has been discussing how ActionScript code should be versioned. We accepted Alex's recommendation that we need to have version info in every class, similar to what Flex provides with its mx_internal VERSION:String const. However, we believe that it would be better if mxmlc implemented a new compiler option like -version="4.0.0.1234" that autogenerated metadata like [Version("4.0.0.1234")] on very class. Developers would access this metadata with describeType().

The advantages of this approach include:

1. Decreased memory usage.

Erik Tierney wrote: "The metadata entry in the swf would be pretty small. It would be 2 strings added to the string table, and then the index of the 2 strings in the metadata entry. There is no runtime impact of metadata until you call describeType. At that time the VM goes pack and parses the metadata in the abc - other than that, the VM ignores it. "

2. Fixing the problem that when we create new classes we often forget to include Version.as.

3. Fixing the problem that the build system has to update a copy of Version.as for each SWC.

4. Relying on fewer include statements, which pleases David Zuckerman.

Pete Farland wrote: "As for compiler effort... it sounds pretty small... could we revisit after beta2?"