| | 1 | {{{ |
| | 2 | From: Gary Byers |
| | 3 | Date: May 26, 2008 4:27:29 AM EDT |
| | 4 | Subject: Re: [Openmcl-devel] Is the Cocoa bridge still tied to exactly one version of the Cocoa frameworks? |
| | 5 | |
| | 6 | On Mon, 26 May 2008, Axel Katerbau wrote: |
| | 7 | |
| | 8 | > Is the Cocoa bridge (ObjC framework brigde in general) still tied to |
| | 9 | > one specific version of the framework? |
| | 10 | > |
| | 11 | > E.g.: Will a shipped application (as a Mac app bundle) likely break |
| | 12 | > with a new version of Mac OS? |
| | 13 | |
| | 14 | No, not in general. |
| | 15 | |
| | 16 | > Some old documentation stated this but a solution to this was kind of |
| | 17 | > announced for the future. What is the state of this? |
| | 18 | |
| | 19 | Until a few years ago, the bridge's notion of what ObjC classes and |
| | 20 | methods existed was based on introspection: it asked the runtime |
| | 21 | to enumerate all classes and methods when it first started up. |
| | 22 | |
| | 23 | This generally included hundreds of classes and thousands of |
| | 24 | methods that weren't documented or described in the interfaces |
| | 25 | (e.g., private, implementation-level internal things.) That |
| | 26 | set of things changed from dot release to dot release, so |
| | 27 | an application saved under (for instance) 10.4.8 found itself |
| | 28 | in a different world when running under 10.4.9, and there |
| | 29 | was no good way to tell whether the differences were significant |
| | 30 | or not. |
| | 31 | |
| | 32 | For the last few years, the bridge's notion of what classes and |
| | 33 | methods exist is based on what's declared in the interfaces. This |
| | 34 | usually only changes between major OS releases and newer releases |
| | 35 | are usually supersets of older ones, so (for instance) something |
| | 36 | built using Tiger interfaces would generally run under Leopard. |
| | 37 | |
| | 38 | Some of this stuff is complicated and there are certainly things |
| | 39 | to go wrong, but it's certainly intended that: |
| | 40 | |
| | 41 | - saved Cocoa applications aren't sensitive to minor OS release |
| | 42 | changes |
| | 43 | |
| | 44 | - saved Cocoa applications don't need access to the interface |
| | 45 | files in order to run (though if the application is some sort |
| | 46 | of development system, the interfaces may be needed to develop |
| | 47 | new code.) |
| | 48 | |
| | 49 | }}} |
