protected override ClassDeclarationSyntax InternalExecute(
ClassWithSourceCode childClass,
SemanticModel semantic,
Settings settings = null)
{
// create a field declaration and add it to the child class
// check the following cases:
// 1. if mixin type is a concrete type that has a parameterless constructor
// if injection setting is not set => init field with new instance of type
// 2. if mixin is interface or does not have a parameterless constructor
// do nothing
var positionOfClassInSourceFile = childClass.SourceCode.GetLocation().SourceSpan.Start;
var typeSyntax = ParseTypeName(
_mixin.Class.TypeSymbol.ReduceQualifiedTypeName(semantic,positionOfClassInSourceFile));
var newFieldDeclaration =
FieldDeclaration(
VariableDeclaration(typeSyntax)
.WithVariables(
SingletonSeparatedList(
VariableDeclarator(_mixin.Name))))
.WithModifiers(TokenList(Token(SyntaxKind.PrivateKeyword)));
var newClassDeclaration = childClass.SourceCode.AddMembers(newFieldDeclaration);
return newClassDeclaration;
}
private async Task<Solution> CreateMixin(
IMixinCommand mixinCommand,
Document document,
ClassWithSourceCode childClass,
CancellationToken cancellationToken)
{
// get service provider and read settings from storage
var serviceProvider = Microsoft.VisualStudio.Shell.ServiceProvider.GlobalProvider;
var settings = new Settings(serviceProvider);
var model = await document.GetSemanticModelAsync(cancellationToken);
if (mixinCommand.CanExecute(childClass,settings))
{
// execute the command => we get a new class declaration
var newClassDeclaration = mixinCommand.Execute(childClass.SourceCode, model,settings);
// replace the old class declaration in the syntax tree
var root = await model.SyntaxTree.GetRootAsync(cancellationToken);
var newRoot = root.ReplaceNode(childClass.SourceCode, newClassDeclaration);
// create a new document from the new syntax tree
var newDocument = document.WithSyntaxRoot(newRoot);
return newDocument.Project.Solution;
}
return null;
}
public override bool CanExecute(ClassWithSourceCode childClass, Settings settings = null)
{
if (settings == null || !settings.InjectMixins)
return false;
return !(childClass.AllConstructorsHaveParameter(_mixin.Name.ConvertFieldNameToParameterName()) &&
childClass.HasConstructor);
}
public override bool CanExecute(ClassWithSourceCode childClass, Settings settings = null)
{
// this feature is only available if the mixin class is an interface
if (Mixin == null || !Mixin.Class.IsInterface)
return false;
return base.CanExecute(childClass, settings);
}
protected override ClassDeclarationSyntax InternalExecute(
ClassWithSourceCode childClass,
SemanticModel semantic,
Settings settings = null)
{
var constructorSyntaxWriter = new ConstructorInjectionSyntaxWriter(_mixin, semantic);
var classDeclaration = (ClassDeclarationSyntax)constructorSyntaxWriter.Visit(childClass.SourceCode);
return classDeclaration;
}
public override bool CanExecute(
ClassWithSourceCode childClass,
Settings settings = null)
{
// ensure that the child class does not already have a
// reference to the mixin with the given name
var mixinField = childClass.SourceCode.FindMixinReference(_mixin.Name);
return mixinField == null;
}
/// <summary>
/// Template method that checks if command can be executed and if yes,
/// executes the command. Otherwise the original source code of the child is returned.
/// </summary>
/// <param name="semantic">semantic model of the child's and mixin's source code</param>
/// <param name="settings">optional settings object</param>
/// <returns>the modified class declaration of the child class after executing
/// the command or the original child's source code if command could not be
/// executed</returns>
public ClassDeclarationSyntax Execute(
ClassDeclarationSyntax childDeclaration,
SemanticModel semantic,
Settings settings = null)
{
var childClass = new ClassFactory(semantic).Create(childDeclaration);
if (CanExecute(childClass, settings))
return InternalExecute(childClass, semantic, settings);
return childClass.SourceCode;
}
public virtual bool CanExecute(ClassWithSourceCode childClass, Settings settings = null)
{
if (Mixin == null)
return false;
var canExecute = false;
// check that at least one command is executable
foreach (var command in _commands)
canExecute = canExecute || command.CanExecute(childClass, settings);
return canExecute;
}
public IncludeMixinSyntaxWriter(
IEnumerable<Member> membersToImplement,
MixinReference mixin,
SemanticModel semanticModel,
Settings settings = null)
{
_members = membersToImplement;
_mixin = mixin;
_semantic = semanticModel;
_settings = settings ?? new Settings();
}
protected override ClassDeclarationSyntax InternalExecute(
ClassWithSourceCode childClass,
SemanticModel semantic,
Settings settings = null)
{
var classDeclaration = childClass.SourceCode;
var positionInSource = classDeclaration.GetLocation().SourceSpan.Start;
var interfaceWriter = new AddInterfacesToChildSyntaxWriter(_mixin, semantic, positionInSource);
classDeclaration = (ClassDeclarationSyntax)interfaceWriter.Visit(classDeclaration);
return classDeclaration;
}
/// <summary>
/// method is virtual, so derived classes can override it to create
/// different strategies (e.g. for testing)
/// </summary>
/// <param name="mixin"></param>
/// <param name="semantic"></param>
/// <param name="settings"></param>
/// <returns></returns>
protected virtual Dictionary<Type, IImplementMemberForwarding> CreateStrategies(
MixinReference mixin, SemanticModel semantic, Settings settings)
{
var implementationStrategies = new Dictionary<Type, IImplementMemberForwarding>
{
[typeof(Method)] = new ImplementMethodForwarding(mixin, _semantic, _settings),
[typeof(IndexerProperty)] = new ImplementIndexerForwarding(mixin, _semantic, _settings),
[typeof(Property)] = new ImplementPropertyForwarding(mixin, _semantic, _settings),
[typeof(Event)] = new ImplementEventForwarding(mixin,_semantic,_settings)
};
return implementationStrategies;
}
public override bool CanExecute(ClassWithSourceCode childClass, Settings settings = null)
{
if (_mixin == null || childClass == null)
return false;
// do the mixin operation the first time
if (_mixer == null)
{
_mixer = new Mixer();
_mixer.IncludeMixinInChild(_mixin, childClass);
}
// command can be executed if we either have to forward members or extend a constructor
return _mixer.MembersToImplement.Any();
}
protected override ClassDeclarationSyntax InternalExecute(
ClassWithSourceCode childClass,
SemanticModel semantic,
Settings settings = null)
{
var syntaxWriter = new IncludeMixinSyntaxWriter(
_mixer.MembersToImplement,
_mixin,
semantic,
settings);
var classDeclaration = (ClassDeclarationSyntax)syntaxWriter.Visit(childClass.SourceCode);
return classDeclaration;
}
public sealed override async Task ComputeRefactoringsAsync(CodeRefactoringContext context)
{
var root = await context.Document.GetSyntaxRootAsync(context.CancellationToken).ConfigureAwait(false);
// Find the node at the selection.
var node = root.FindNode(context.Span);
var model = await context.Document.GetSemanticModelAsync(context.CancellationToken).ConfigureAwait(false);
CompositeCommand command = null;
// create mixin from base type
var baseTypeSyntax = node as SimpleBaseTypeSyntax;
// create command depending on the selected node
if (baseTypeSyntax != null)
{
command = new CreateMixinFromInterfaceCommand(baseTypeSyntax, model);
}
else
{
var fieldDeclarationNode = GetContainingFieldDeclaration(node);
if (fieldDeclarationNode != null)
command = new CreateMixinFromFieldDeclarationCommand(fieldDeclarationNode, model);
}
if (command == null)
return;
// get service provider and read settings from storage
var serviceProvider = Microsoft.VisualStudio.Shell.ServiceProvider.GlobalProvider;
var settings = new Settings(serviceProvider);
var childClassDeclaration = node.FindContainingClass();
var childClass = new ClassFactory(model).Create(childClassDeclaration);
if (!command.CanExecute(childClass, settings))
return;
var action = CodeAction.Create(
command.Title,
c => CreateMixin(command, context.Document, childClass, c));
// Register this code action.
context.RegisterRefactoring(action);
}
public ClassDeclarationSyntax Execute(
ClassDeclarationSyntax childDeclaration,
SemanticModel semantic,
Settings settings = null)
{
// we need the class name of the child to find it in the syntax tree
// after it was changed
var childClassName = childDeclaration.Identifier.Text.ToString();
foreach (var command in _commands)
{
var oldSyntaxTree = childDeclaration.SyntaxTree;
var newChildDeclaration = command.Execute(childDeclaration, semantic, settings);
// replace the old class declaration with the new one in the syntax tree
var newRoot = semantic.SyntaxTree.GetRoot().ReplaceNode(childDeclaration, newChildDeclaration);
var newSyntaxTree = newRoot.SyntaxTree;
var compilation = semantic.Compilation.ReplaceSyntaxTree(oldSyntaxTree,newSyntaxTree);
// after creating the new syntax tree, get a new semantic model
semantic = compilation.GetSemanticModel(newSyntaxTree);
// also retrieve the class declaration from the new syntax tree
childDeclaration = newRoot.FindClassByName(childClassName);
}
return childDeclaration;
}
/// <summary>
/// executes the command on the given child class.
/// Logic of command execution must be implemented in derived classes.
/// </summary>
/// <param name="semantic">semantic model of the child's and mixin's source code</param>
/// <param name="settings">optional settings object</param>
/// <returns></returns>
protected abstract ClassDeclarationSyntax InternalExecute(
ClassWithSourceCode childClass,
SemanticModel semantic,
Settings settings = null);
/// <summary>
/// called to check if the command can be executed.
/// </summary>
/// <param name="settings">optional settings</param>
/// <returns>true if the command can be executed, otherwise false</returns>
public abstract bool CanExecute(
ClassWithSourceCode childClass,
Settings settings = null);
public override bool CanExecute(ClassWithSourceCode childClass, Settings settings = null)
{
return settings != null && settings.AddInterfacesToChild;
}