“Hello World” Example with AspectDNG

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6. “Hello World” Example with AspectDNG

In this chapter, let’s try to use AspectDNG to do an AOP example together. 

Firstly, I define the base and aspect assemblies as below:

TestBaseClass.cs in BaseLib.dll

using System;

namespace BaseLib

TestAspectClass.cs in AspectLib.dll

using System;

namespace AspectLib

The AspectDngConfig and Advice configuration are as below:

AspectDngConfig.xml

<?xml version="1.0" encoding="utf-8"?>
<AspectDngConfig xmlns="http://www.dotnetguru.org/AspectDNG"
    debug="false" 
    logWarnings="true" logWarningsPath="Warnings.log"
    logIlml="true" logIlmlPath="BaseLib.ilml.xml"
    logWeaving="true" logWeavingPath="BaseLib.weaving.xml"
    validateRules="true">
    
    <BaseAssembly>BaseLib/bin/Debug/BaseLib.dll</BaseAssembly>
    <AspectsAssembly>AspectLib/bin/Debug/AspectLib.dll</AspectsAssembly>
    
    <AdviceFiles>
        <AdviceFile>HelloAspectDngAdvice.xml</AdviceFile>
    </AdviceFiles>
</AspectDngConfig>

HelloAspectDngAdvice.xml

<Advice xmlns="http://www.dotnetguru.org/AspectDNG">
    <Delete 
        targetXPath="//Method[@name = 'MethodToBeDeleted']"/>
        
    <Insert 
        aspectXPath="//Type[@name = 'TestClassToBeInserted']"
        targetXPath="//Module"/>

    <!--<Warning 
        targetXPath="//Method[@name = 'MethodWarningToBeAdded']"/>-->

    <!--<Error 
        targetXPath="//Method[@name = 'MethodErrorToBeAdded']"/>-->
    
    <!--<MakeSerializable 
        targetXPath="//Method[@name = 'TestBaseClass']"/>-->
        
    <!--<SetBaseType 
        aspectXPath="//Type[@name = 'TestClassToBeInserted']"
        targetXPath="//Type[@name = 'TestBaseClass']"/>-->
    
    <!--<InlineBeforeConstructorCall 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeConstuctorCall']"
        targetXPath="//TestBaseClass/Constructor"/>
    
    <InlineAfterConstructorCall 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAfterConstuctorCall']"
        targetXPath="//TestBaseClass/Constructor"/>
    
    <InlineBeforeMethodCall 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeMethodCall']"
        targetXPath="//Method[@name = 'MethodToTestInlineMethod']"/>
    
    <InlineAfterMethodCall 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAfterMethodCall']"
        targetXPath="//Method[@name = 'MethodToTestInlineMethod']"/>
    
    <InlineBeforeFieldReadAccess 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeFieldReadAccess']"
        targetXPath="//Field[@name = 'fieldToTestInlineField']"/>
    
    <InlineAfterFieldReadAccess 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAfterFieldReadAccess']"
        targetXPath="//Field[@name = 'fieldToTestInlineField']"/>
    
    <InlineBeforeFieldWriteAccess 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeFieldWriteAccess']"
        targetXPath="//Field[@name = 'fieldToTestInlineField']"/>
    
    <InlineAfterFieldWriteAccess 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAfterFieldWriteAccess']"
        targetXPath="//Field[@name = 'fieldToTestInlineField']"/>-->
        
    <InlineAtStart 
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAtStart']"
        targetXPath="//Method[@name = 'MethodToTestInlineMethod']"/>
    
    <InlineBeforeReturn
        aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeReturn']"
        targetXPath="//Method[@name = 'MethodToTestInlineMethod']"/>
    
    <!--<AroundCall 
        aspectXPath="//Method[@name='CodeToBeAddedAsAroundCall']"
        targetXPath="//Method[@name = 'MethodToTestAroundBody']"/>-->
    
    <AroundBody 
        aspectXPath="//Method[@name='CodeToBeAddedAsAroundBody']"
        targetXPath="//Method[@name = 'MethodToTestAroundBody']"/>
</Advice>

After execute the command:

aspectdng.exe –w AspectDngConfig.xml

BaseLib.dll is statically weaved and the source code (decompiled by Salamander) becomes below:

// Decompiled by Salamander version 1.0.6
// Copyright 2002 Remotesoft Inc. All rights reserved.
// http://www.remotesoft.com/salamander

using System;

namespace BaseLib

Conclusion

The uncommented operations defined in HelloAspectDngAdvice.xml are executed successfully. The commented code was also tested, but either failed or ignored by AspectDNG, seams they haven’t been supported correctly or not supported yet. And we can also check the weaving log file. 

BaseLib.weaving.xml

<WeaveLog>
  <Weave name="Delete" targetXPath="//Method[@name = 'MethodToBeDeleted']">
    <WeaveStep>
      <TargetInfo>System.Void BaseLib.TestBaseClass::MethodToBeDeleted()</TargetInfo>
    </WeaveStep>
  </Weave>
  <Weave name="Insert" aspectXPath="//Type[@name = 'TestClassToBeInserted']" targetXPath="//Module">
    <WeaveStep>
      <AspectInfo>AspectLib.TestClassToBeInserted</AspectInfo>
      <TargetInfo>BaseLib.dll</TargetInfo>
    </WeaveStep>
  </Weave>
  <Weave name="InlineAtStart" aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineAtStart']" targetXPath="//Method[@name = 'MethodToTestInlineMethod']">
    <WeaveStep>
      <AspectInfo>System.Void AspectLib.TestAspectClass::CodeToBeAddedAsInlineAtStart()</AspectInfo>
      <TargetInfo>System.Void BaseLib.TestBaseClass::MethodToTestInlineMethod()</TargetInfo>
    </WeaveStep>
  </Weave>
  <Weave name="InlineBeforeReturn" aspectXPath="//Method[@name = 'CodeToBeAddedAsInlineBeforeReturn']" targetXPath="//Method[@name = 'MethodToTestInlineMethod']">
    <WeaveStep>
      <AspectInfo>System.Void AspectLib.TestAspectClass::CodeToBeAddedAsInlineBeforeReturn()</AspectInfo>
      <TargetInfo>System.Void BaseLib.TestBaseClass::MethodToTestInlineMethod()</TargetInfo>
    </WeaveStep>
  </Weave>
  <Weave name="AroundBody" aspectXPath="//Method[@name='CodeToBeAddedAsAroundBody']" targetXPath="//Method[@name = 'MethodToTestAroundBody']">
    <WeaveStep>
      <AspectInfo>System.Void AspectLib.TestAspectClass::CodeToBeAddedAsAroundBody()</AspectInfo>
      <TargetInfo>System.Void BaseLib.TestBaseClass::MethodToTestAroundBody()</TargetInfo>
    </WeaveStep>
  </Weave>
</WeaveLog>

Source Code Download

HelloAspectDNG.zip