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Line 285: − There are two methods to define slots:+ − * in service that uses dependency with slots − * in dependency itself − − In first case, ''slots'' and appropriate ''requires'' options should be placed to ''[Service]'' section that uses dependency: − In second case, ''slots'' option should be placed to ''[Service]'' section that is used:+ − − slots = <versions-range> − − In both cases, ''slots'' option will declare compatibility ranges for particular dependency. Only one, closed from both sides, range could be used. For example in cairo case, it could be:
Sugar Network/Recipe Specification (view source)
Revision as of 07:32, 8 June 2010
, 07:32, 8 June 2010→Slots
Assume that service requires cairo and source code uses cairo feature that appeared only in v1.8 but source code can fallback to previous cairo verisons too. If cairo can be installed from 0install feeds, there is no need in slots since service can declare "cairo >= 1.8" dependency and such cairo will be installed from 0install feeds. But if cairo could be installed from native packages there are no chances to know in advance what cairo version will present and service should have two implementations, one for cairo < 1.8 and one for cairo >= 1.8. In this case, slots will be useful.
Assume that service requires cairo and source code uses cairo feature that appeared only in v1.8 but source code can fallback to previous cairo verisons too. If cairo can be installed from 0install feeds, there is no need in slots since service can declare "cairo >= 1.8" dependency and such cairo will be installed from 0install feeds. But if cairo could be installed from native packages there are no chances to know in advance what cairo version will present and service should have two implementations, one for cairo < 1.8 and one for cairo >= 1.8. In this case, slots will be useful.
To declare slots for used dependency, ''slots'' and appropriate ''requires'' options should be placed to ''[Service]'' section that uses dependency:
requires = <dependency>
requires = <dependency>
slots[<dependency>] = <versions-range>
slots[<dependency>] = <versions-range>
Option ''slots'' will declare compatibility ranges for particular dependency. Only one, closed from both sides, range could be used. For example in cairo case, it could be:
1.0, 1.8, 2.0
1.0, 1.8, 2.0