Makefile
The Makefile is provided with the module generated from getTemplateForDirectory. In the case of Python server implementation, you need to configure the compilation and installation of a Python Package:
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PY_PACKAGES:=<PackageName> |
Implementation
The first thing needed to implement a server, is to import the required modules and classes:
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| language | bashpy |
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| title | Environment PreparationPython Imports |
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#Client stubs and definitions, such as structs, enums, etc.
import <Module>
#Skeleton infrastructure for server implementation
import <Module>__POA
#Base component implementation
from Acspy.Servants.ACSComponent import ACSComponent
#Services provided by the container to the component
from Acspy.Servants.ContainerServices import ContainerServices
#Basic component lifecycle (initialize, execute, cleanUp and aboutToAbort methods)
from Acspy.Servants.ComponentLifecycle import ComponentLifecycle
#Error definitions for catching exceptions
import ServiceErr
import <Interface>Err
#Error definitions for creating and raising exceptions
import ServiceErrImpl
import <Interface>ErrImpl |
Besides this, there's the need to create the class using the mentioned infrastructure provided by some of the imported classes:
| Code Block |
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| language | bashpy |
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| title | Environment PreparationPython Server Class Definition |
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class <Name>(<Module>__POA.<InterfaceName>, ACSComponent, ContainerServices, ComponentLifecycle):
def __init__(self):
ACSComponent.__init__(self)
ContainerServices.__init__(self)
self._logger = self.getLogger()
... #Custom implementation for the server constructor |
To access a struct, enum, typedef or definition in a module or in an interface, simply do the following:
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| language | bashpy |
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| title | Environment PreparationPython Types Usage |
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#From IDL <Module>::<EnumName>::READY<VALUE>
<Module>.READY
<VALUE>
#From IDL <Module>::<Interface>::<Enumname>::OFFLINE<VALUE>
Observatory<Module>.Service<Interface>.OFFLINE<VALUE> |
To retrieve a component to interact with, simply do the following:
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| language | bashpy |
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| title | Environment PreparationPython Component Interaction |
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#By Name
comp = self.getComponent("<Name>")
#By Interface. Must be at least one component configured as default!
comp = self.getDefaultComponent("IDL:alma/<Module>/<Interface>:1.0")
#Release Components
self.releaseComponent(comp.name()) |
For logging, as you saw in the class constructor, there's a facility provided by the component. To use it, simply do as follows:
| Code Block |
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| language | bashpy |
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| title | Environment PreparationPython Logger |
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logger = self.getLogger()
logger.logTrace("...")
logger.logDebug("...")
logger.logInfo("...")
logger.logWarning("...")
logger.logError("...") |
For catching and raising exceptions:
| Code Block |
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| language | bashpy |
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| title | Environment PreparationPython Error Handling |
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#For catching exceptions
except <Interface>Err.<ExceptionName>Ex as e:
#For raising exceptions
raise <Interface>ErrImpl.<ExceptionName>ExImpl().get<ExceptionName>Ex()
#For raising exceptions with parameters
err = <Interface>ErrImpl.<ExceptionName>ExImpl()
err.set<ParamName>(<Value>)
raise err.get<ExceptionName>Ex()
#For logging an error message from the exceptions
err = <Interface>ErrImpl.<ExceptionName>ExImpl()
err.log()
raise err.get<ExceptionName>Ex() |
