DirectiveProcessor, classe
Classe de base abstraite d'un processeur de directive concrète.
Hiérarchie d'héritage
System.Object
Microsoft.VisualStudio.TextTemplating.DirectiveProcessor
Microsoft.VisualStudio.TextTemplating.ParameterDirectiveProcessor
Microsoft.VisualStudio.TextTemplating.RequiresProvidesDirectiveProcessor
Espace de noms : Microsoft.VisualStudio.TextTemplating
Assembly : Microsoft.VisualStudio.TextTemplating.11.0 (dans Microsoft.VisualStudio.TextTemplating.11.0.dll)
Syntaxe
'Déclaration
Public MustInherit Class DirectiveProcessor _
Implements IDirectiveProcessor
public abstract class DirectiveProcessor : IDirectiveProcessor
public ref class DirectiveProcessor abstract : IDirectiveProcessor
[<AbstractClass>]
type DirectiveProcessor =
class
interface IDirectiveProcessor
end
public abstract class DirectiveProcessor implements IDirectiveProcessor
Le type DirectiveProcessor expose les membres suivants.
Constructeurs
| Nom | Description | |
|---|---|---|
.gif "Méthode protégée") |
DirectiveProcessor | En cas de substitution dans une classe dérivée, initialise une nouvelle instance de la classe DirectiveProcessor. |
Début
Propriétés
| Nom | Description | |
|---|---|---|
.gif "Propriété protégée") |
Errors | Obtient les erreurs survenues lors de le traitement des directives. |
Début
Méthodes
| Nom | Description | |
|---|---|---|
.gif "Méthode publique") |
Equals | Détermine si l'objet spécifié est identique à l'objet actuel. (Hérité de Object.) |
|
Finalize | Autorise un objet à tenter de libérer des ressources et d'exécuter d'autres opérations de nettoyage avant qu'il ne soit récupéré par l'opération garbage collection. (Hérité de Object.) |
|
FinishProcessingRun | En cas de substitution dans une classe dérivée, termine un cycle de traitement de directive. |
|
GetClassCodeForProcessingRun | En cas de substitution dans une classe dérivée, obtient le code à ajouter à la classe de transformation générée. |
|
GetHashCode | Sert de fonction de hachage pour un type particulier. (Hérité de Object.) |
|
GetImportsForProcessingRun | En cas de substitution dans une classe dérivée, obtient des espaces de noms à importer dans la classe de transformation générée. |
|
GetPostInitializationCodeForProcessingRun | En cas de substitution dans une classe dérivée, obtient le code à ajouter à la fin de la méthode initialize de la classe de transformation générée. |
|
GetPreInitializationCodeForProcessingRun | Une fois substituée dans une classe dérivée, obtient le code pour ajouter au début de la méthode initialize de classe de transformation générée. |
|
GetReferencesForProcessingRun | En cas de substitution dans une classe dérivée, obtient les références à passer au compilateur de la classe de transformation générée. |
|
GetTemplateClassCustomAttributes | Obtient tous les attributs personnalisés pour mettre en fonction de la classe de modèle. |
|
GetType | Obtient le Type de l'instance actuelle. (Hérité de Object.) |
|
Initialize | En cas de substitution dans une classe dérivée, initialise l'instance de processeur. |
|
IsDirectiveSupported | Une fois substituée dans une classe dérivée, détermine si le processeur de directive prend en charge la directive spécifiée. |
|
MemberwiseClone | Crée une copie superficielle de l'objet Object actuel. (Hérité de Object.) |
|
ProcessDirective | En cas de substitution dans une classe dérivée, traite une directive unique d'un fichier de modèle. |
|
StartProcessingRun | Une fois substituée dans une classe dérivée, démarre un traitement rond de directive. |
|
ToString | Retourne une chaîne qui représente l'objet actuel. (Hérité de Object.) |
Début
Implémentations d'interface explicite
| Nom | Description | |
|---|---|---|
.gif "Implémentation d'interface explicite") .gif "Propriété privée") |
IDirectiveProcessor.Errors | |
|
IDirectiveProcessor.RequiresProcessingRunIsHostSpecific | |
.gif "Méthode privée") |
IDirectiveProcessor.SetProcessingRunIsHostSpecific |
Début
Notes
Le processus de transformation de modèle de texte comporte deux étapes.Dans la première étape, le moteur de transformation du modèle de texte crée une classe qui est référencée en tant que classe de transformation générée.Dans la deuxième étape, le moteur compile et exécute la classe de transformation générée, pour produire la sortie de texte générée.
Les processeurs de directive fonctionnent en ajoutant du code à la classe de transformation générée.Vous appelez des directives depuis un modèle de texte, et une fois la directive appelée, le reste du code que vous écrivez dans votre modèle de texte peut compter sur les fonctionnalités fournies par la directive.Vous pouvez écrire vos propres processeurs de directives personnalisés pour fournir des fonctionnalités personnalisées aux modèles de texte.
Pour plus d'informations, consultez Création de processeurs de directives de modèles de texte T4 personnalisés.
Le moteur de transformation du modèle de texte contiendra une instance singleton de toutes les classes DirectiveProcessor obligatoires.
DirectiveProcessor implémente une machine à états.
Par exemple, si un modèle de texte a trois appels de directive au même processeur de directives, le moteur appellera les méthodes suivantes dans l'ordre suivant :
StartProcessingRun
Exemples
L'exemple suivant crée un processeur de directive personnalisé.Le processeur de directive personnalisé contient une directive qui lit un fichier XML.La directive stocke le XML dans une variable XmlDocument et expose le XmlDocument via une propriété.
Pour plus d'informations, consultez Procédure pas à pas : création d'un processeur de directive personnalisé.
using System;
using System.CodeDom;
using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Serialization;
using Microsoft.VisualStudio.TextTemplating;
namespace CustomDP
{
public class CustomDirectiveProcessor : DirectiveProcessor
{
//this buffer stores the code that is added to the
//generated transformation class after all the processing is done
//---------------------------------------------------------------------
private StringBuilder codeBuffer;
//Using a Code Dom Provider creates code for the
//generated transformation class in either Visual Basic or C#.
//If you want your directive processor to support only one language, you
//can hard code the code you add to the generated transformation class.
//In that case, you do not need this field.
//--------------------------------------------------------------------------
private CodeDomProvider codeDomProvider;
//this stores the full contents of the text template that is being processed
//--------------------------------------------------------------------------
private String templateContents;
//These are the errors that occur during processing. The engine passes
//the errors to the host, and the host can decide how to display them,
//for example the the host can display the errors in the UI
//or write them to a file.
//---------------------------------------------------------------------
private CompilerErrorCollection errorsValue;
public new CompilerErrorCollection Errors
{
get { return errorsValue; }
}
//Each time this directive processor is called, it creates a new property.
//We count how many times we are called, and append "n" to each new
//property name. The property names are therefore unique.
//-----------------------------------------------------------------------------
private int directiveCount = 0;
public override void Initialize(ITextTemplatingEngineHost host)
{
//we do not need to do any initialization work
}
public override void StartProcessingRun(CodeDomProvider languageProvider, String templateContents, CompilerErrorCollection errors)
{
//the engine has passed us the language of the text template
//we will use that language to generate code later
//----------------------------------------------------------
this.codeDomProvider = languageProvider;
this.templateContents = templateContents;
this.errorsValue = errors;
this.codeBuffer = new StringBuilder();
}
//Before calling the ProcessDirective method for a directive, the
//engine calls this function to see whether the directive is supported.
//Notice that one directive processor might support many directives.
//---------------------------------------------------------------------
public override bool IsDirectiveSupported(string directiveName)
{
if (string.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) == 0)
{
return true;
}
if (string.Compare(directiveName, "SuperCoolDirective", StringComparison.OrdinalIgnoreCase) == 0)
{
return true;
}
return false;
}
public override void ProcessDirective(string directiveName, IDictionary<string, string> arguments)
{
if (string.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) == 0)
{
string fileName;
if (!arguments.TryGetValue("FileName", out fileName))
{
throw new DirectiveProcessorException("Required argument 'FileName' not specified.");
}
if (string.IsNullOrEmpty(fileName))
{
throw new DirectiveProcessorException("Argument 'FileName' is null or empty.");
}
//Now we add code to the generated transformation class.
//This directive supports either Visual Basic or C#, so we must use the
//System.CodeDom to create the code.
//If a directive supports only one language, you can hard code the code.
//--------------------------------------------------------------------------
CodeMemberField documentField = new CodeMemberField();
documentField.Name = "document" + directiveCount + "Value";
documentField.Type = new CodeTypeReference(typeof(XmlDocument));
documentField.Attributes = MemberAttributes.Private;
CodeMemberProperty documentProperty = new CodeMemberProperty();
documentProperty.Name = "Document" + directiveCount;
documentProperty.Type = new CodeTypeReference(typeof(XmlDocument));
documentProperty.Attributes = MemberAttributes.Public;
documentProperty.HasSet = false;
documentProperty.HasGet = true;
CodeExpression fieldName = new CodeFieldReferenceExpression(new CodeThisReferenceExpression(), documentField.Name);
CodeExpression booleanTest = new CodeBinaryOperatorExpression(fieldName, CodeBinaryOperatorType.IdentityEquality, new CodePrimitiveExpression(null));
CodeExpression rightSide = new CodeMethodInvokeExpression(new CodeTypeReferenceExpression("XmlReaderHelper"), "ReadXml", new CodePrimitiveExpression(fileName));
CodeStatement[] thenSteps = new CodeStatement[] { new CodeAssignStatement(fieldName, rightSide) };
CodeConditionStatement ifThen = new CodeConditionStatement(booleanTest, thenSteps);
documentProperty.GetStatements.Add(ifThen);
CodeStatement s = new CodeMethodReturnStatement(fieldName);
documentProperty.GetStatements.Add(s);
CodeGeneratorOptions options = new CodeGeneratorOptions();
options.BlankLinesBetweenMembers = true;
options.IndentString = " ";
options.VerbatimOrder = true;
options.BracingStyle = "C";
using (StringWriter writer = new StringWriter(codeBuffer, CultureInfo.InvariantCulture))
{
codeDomProvider.GenerateCodeFromMember(documentField, writer, options);
codeDomProvider.GenerateCodeFromMember(documentProperty, writer, options);
}
}//end CoolDirective
//One directive processor can contain many directives.
//If you want to support more directives, the code goes here...
//-----------------------------------------------------------------
if (string.Compare(directiveName, "supercooldirective", StringComparison.OrdinalIgnoreCase) == 0)
{
//code for SuperCoolDirective goes here...
}//end SuperCoolDirective
//Track how many times the processor has been called.
//-----------------------------------------------------------------
directiveCount++;
}//end ProcessDirective
public override void FinishProcessingRun()
{
this.codeDomProvider = null;
//important: do not do this:
//the get methods below are called after this method
//and the get methods can access this field
//-----------------------------------------------------------------
//this.codeBuffer = null;
}
public override string GetPreInitializationCodeForProcessingRun()
{
//Use this method to add code to the start of the
//Initialize() method of the generated transformation class.
//We do not need any pre-initialization, so we will just return "".
//-----------------------------------------------------------------
//GetPreInitializationCodeForProcessingRun runs before the
//Initialize() method of the base class.
//-----------------------------------------------------------------
return String.Empty;
}
public override string GetPostInitializationCodeForProcessingRun()
{
//Use this method to add code to the end of the
//Initialize() method of the generated transformation class.
//We do not need any post-initialization, so we will just return "".
//------------------------------------------------------------------
//GetPostInitializationCodeForProcessingRun runs after the
//Initialize() method of the base class.
//-----------------------------------------------------------------
return String.Empty;
}
public override string GetClassCodeForProcessingRun()
{
//Return the code to add to the generated transformation class.
//-----------------------------------------------------------------
return codeBuffer.ToString();
}
public override string[] GetReferencesForProcessingRun()
{
//This returns the references that we want to use when
//compiling the generated transformation class.
//-----------------------------------------------------------------
//We need a reference to this assembly to be able to call
//XmlReaderHelper.ReadXml from the generated transformation class.
//-----------------------------------------------------------------
return new string[]
{
"System.Xml",
this.GetType().Assembly.Location
};
}
public override string[] GetImportsForProcessingRun()
{
//This returns the imports or using statements that we want to
//add to the generated transformation class.
//-----------------------------------------------------------------
//We need CustomDP to be able to call XmlReaderHelper.ReadXml
//from the generated transformation class.
//-----------------------------------------------------------------
return new string[]
{
"System.Xml",
"CustomDP"
};
}
}//end class CustomDirectiveProcessor
//-------------------------------------------------------------------------
// the code that we are adding to the generated transformation class
// will call this method
//-------------------------------------------------------------------------
public static class XmlReaderHelper
{
public static XmlDocument ReadXml(string fileName)
{
XmlDocument d = new XmlDocument();
using (XmlTextReader reader = new XmlTextReader(fileName))
{
try
{
d.Load(reader);
}
catch (System.Xml.XmlException e)
{
throw new DirectiveProcessorException("Unable to read the XML file.", e);
}
}
return d;
}
}//end class XmlReaderHelper
}//end namespace CustomDP
Imports System
Imports System.CodeDom
Imports System.CodeDom.Compiler
Imports System.Collections.Generic
Imports System.Globalization
Imports System.IO
Imports System.Text
Imports System.Xml
Imports System.Xml.Serialization
Imports Microsoft.VisualStudio.TextTemplating
Namespace CustomDP
Public Class CustomDirectiveProcessor
Inherits DirectiveProcessor
'this buffer stores the code that is added to the
'generated transformation class after all the processing is done
'---------------------------------------------------------------
Private codeBuffer As StringBuilder
'Using a Code Dom Provider creates code for the
'generated transformation class in either Visual Basic or C#.
'If you want your directive processor to support only one language, you
'can hard code the code you add to the generated transformation class.
'In that case, you do not need this field.
'--------------------------------------------------------------------------
Private codeDomProvider As CodeDomProvider
'this stores the full contents of the text template that is being processed
'--------------------------------------------------------------------------
Private templateContents As String
'These are the errors that occur during processing. The engine passes
'the errors to the host, and the host can decide how to display them,
'for example the the host can display the errors in the UI
'or write them to a file.
'---------------------------------------------------------------------
Private errorsValue As CompilerErrorCollection
Public Shadows ReadOnly Property Errors() As CompilerErrorCollection
Get
Return errorsValue
End Get
End Property
'Each time this directive processor is called, it creates a new property.
'We count how many times we are called, and append "n" to each new
'property name. The property names are therefore unique.
'--------------------------------------------------------------------------
Private directiveCount As Integer = 0
Public Overrides Sub Initialize(ByVal host As ITextTemplatingEngineHost)
'we do not need to do any initialization work
End Sub
Public Overrides Sub StartProcessingRun(ByVal languageProvider As CodeDomProvider, ByVal templateContents As String, ByVal errors As CompilerErrorCollection)
'the engine has passed us the language of the text template
'we will use that language to generate code later
'----------------------------------------------------------
Me.codeDomProvider = languageProvider
Me.templateContents = templateContents
Me.errorsValue = errors
Me.codeBuffer = New StringBuilder()
End Sub
'Before calling the ProcessDirective method for a directive, the
'engine calls this function to see whether the directive is supported.
'Notice that one directive processor might support many directives.
'---------------------------------------------------------------------
Public Overrides Function IsDirectiveSupported(ByVal directiveName As String) As Boolean
If String.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) = 0 Then
Return True
End If
If String.Compare(directiveName, "SuperCoolDirective", StringComparison.OrdinalIgnoreCase) = 0 Then
Return True
End If
Return False
End Function
Public Overrides Sub ProcessDirective(ByVal directiveName As String, ByVal arguments As IDictionary(Of String, String))
If String.Compare(directiveName, "CoolDirective", StringComparison.OrdinalIgnoreCase) = 0 Then
Dim fileName As String
If Not (arguments.TryGetValue("FileName", fileName)) Then
Throw New DirectiveProcessorException("Required argument 'FileName' not specified.")
End If
If String.IsNullOrEmpty(fileName) Then
Throw New DirectiveProcessorException("Argument 'FileName' is null or empty.")
End If
'Now we add code to the generated transformation class.
'This directive supports either Visual Basic or C#, so we must use the
'System.CodeDom to create the code.
'If a directive supports only one language, you can hard code the code.
'--------------------------------------------------------------------------
Dim documentField As CodeMemberField = New CodeMemberField()
documentField.Name = "document" & directiveCount & "Value"
documentField.Type = New CodeTypeReference(GetType(XmlDocument))
documentField.Attributes = MemberAttributes.Private
Dim documentProperty As CodeMemberProperty = New CodeMemberProperty()
documentProperty.Name = "Document" & directiveCount
documentProperty.Type = New CodeTypeReference(GetType(XmlDocument))
documentProperty.Attributes = MemberAttributes.Public
documentProperty.HasSet = False
documentProperty.HasGet = True
Dim fieldName As CodeExpression = New CodeFieldReferenceExpression(New CodeThisReferenceExpression(), documentField.Name)
Dim booleanTest As CodeExpression = New CodeBinaryOperatorExpression(fieldName, CodeBinaryOperatorType.IdentityEquality, New CodePrimitiveExpression(Nothing))
Dim rightSide As CodeExpression = New CodeMethodInvokeExpression(New CodeTypeReferenceExpression("XmlReaderHelper"), "ReadXml", New CodePrimitiveExpression(fileName))
Dim thenSteps As CodeStatement() = New CodeStatement() {New CodeAssignStatement(fieldName, rightSide)}
Dim ifThen As CodeConditionStatement = New CodeConditionStatement(booleanTest, thenSteps)
documentProperty.GetStatements.Add(ifThen)
Dim s As CodeStatement = New CodeMethodReturnStatement(fieldName)
documentProperty.GetStatements.Add(s)
Dim options As CodeGeneratorOptions = New CodeGeneratorOptions()
options.BlankLinesBetweenMembers = True
options.IndentString = " "
options.VerbatimOrder = True
options.BracingStyle = "VB"
Using writer As StringWriter = New StringWriter(codeBuffer, CultureInfo.InvariantCulture)
codeDomProvider.GenerateCodeFromMember(documentField, writer, options)
codeDomProvider.GenerateCodeFromMember(documentProperty, writer, options)
End Using
End If 'CoolDirective
'One directive processor can contain many directives.
'If you want to support more directives, the code goes here...
'-----------------------------------------------------------------
If String.Compare(directiveName, "supercooldirective", StringComparison.OrdinalIgnoreCase) = 0 Then
'code for SuperCoolDirective goes here
End If 'SuperCoolDirective
'Track how many times the processor has been called.
'-----------------------------------------------------------------
directiveCount += 1
End Sub 'ProcessDirective
Public Overrides Sub FinishProcessingRun()
Me.codeDomProvider = Nothing
'important: do not do this:
'the get methods below are called after this method
'and the get methods can access this field
'-----------------------------------------------------------------
'Me.codeBuffer = Nothing
End Sub
Public Overrides Function GetPreInitializationCodeForProcessingRun() As String
'Use this method to add code to the start of the
'Initialize() method of the generated transformation class.
'We do not need any pre-initialization, so we will just return "".
'-----------------------------------------------------------------
'GetPreInitializationCodeForProcessingRun runs before the
'Initialize() method of the base class.
'-----------------------------------------------------------------
Return String.Empty
End Function
Public Overrides Function GetPostInitializationCodeForProcessingRun() As String
'Use this method to add code to the end of the
'Initialize() method of the generated transformation class.
'We do not need any post-initialization, so we will just return "".
'------------------------------------------------------------------
'GetPostInitializationCodeForProcessingRun runs after the
'Initialize() method of the base class.
'-----------------------------------------------------------------
Return String.Empty
End Function
Public Overrides Function GetClassCodeForProcessingRun() As String
'Return the code to add to the generated transformation class.
'-----------------------------------------------------------------
Return codeBuffer.ToString()
End Function
Public Overrides Function GetReferencesForProcessingRun() As String()
'This returns the references that we want to use when
'compiling the generated transformation class.
'-----------------------------------------------------------------
'We need a reference to this assembly to be able to call
'XmlReaderHelper.ReadXml from the generated transformation class.
'-----------------------------------------------------------------
Return New String() {"System.Xml", Me.GetType().Assembly.Location}
End Function
Public Overrides Function GetImportsForProcessingRun() As String()
'This returns the imports or using statements that we want to
'add to the generated transformation class.
'-----------------------------------------------------------------
'We need CustomDP to be able to call XmlReaderHelper.ReadXml
'from the generated transformation class.
'-----------------------------------------------------------------
Return New String() {"System.Xml", "CustomDP"}
End Function
End Class 'CustomDirectiveProcessor
'--------------------------------------------------------------------------
' the code that we are adding to the generated transformation class
' will call this method
'--------------------------------------------------------------------------
Public Class XmlReaderHelper
Public Shared Function ReadXml(ByVal fileName As String) As XmlDocument
Dim d As XmlDocument = New XmlDocument()
Using reader As XmlTextReader = New XmlTextReader(fileName)
Try
d.Load(reader)
Catch e As System.Xml.XmlException
Throw New DirectiveProcessorException("Unable to read the XML file.", e)
End Try
End Using
Return d
End Function
End Class 'XmlReaderHelper
End Namespace
Sécurité des threads
Tous les membres static (Shared en Visual Basic) publics de ce type sont thread-safe. Il n'est pas garanti que les membres d'instance soient thread-safe.
Voir aussi
Référence
Microsoft.VisualStudio.TextTemplating, espace de noms
RequiresProvidesDirectiveProcessor
Autres ressources
Création de processeurs de directives de modèles de texte T4 personnalisés
Procédure pas à pas : création d'un processeur de directive personnalisé