All geek questions in one place

T4 for creating POCOs over LLBLGen Pro objects?

As I understand it, LLBLGen Pro cannot generate POCOs over its own objects (see here: http://www.llblgen.com/Pages/featuresLLBLGenPro.aspx ).

Has anyone written T4 that will generate the POCO classes corresponding to LLBLGen Pro objects and create the appropriate transformation logic to go to the entity and POCO? Has anyone else come up with a solution that does not include manually recording tons of transformation code?

+6
source share
1 answer

We generated DTO from LLBLGen instead of using T4.

We needed to create a DTO from Entity. These are not technically POCOs because they have a ToEntity() and FromEntity() method, but maybe this will work for you.

We created the IDTO<T> interface, which was then implemented by the DTO classes (one for each object). Instead of modifying entity patterns, we added DTOExtension methods that convert Entity to DTO (as well as many other helper transforms).

Here are the template files that you can use in LLBLGen v2.6. The template designer in version 3 is much easier to use, and you can convert most of this code to version 3 if you need to.

File: entityDTOInterface.template

 using System; using System.ComponentModel; using System.Collections; using System.Runtime.Serialization; using <[RootNamespace]>.HelperClasses; using <[RootNamespace]>.EntityClasses; using SD.LLBLGen.Pro.ORMSupportClasses; namespace <[RootNamespace]>.DTOClasses { /// <summary> /// DTO interface. /// </summary> public interface IDTO<T> { T ToEntity(T toFill); IDTO<T> FromEntity(T entityInstance, Hashtable seenObjects, Hashtable parents); } }

File: entityDTO.template

 using System; using System.ComponentModel; using System.Collections; using System.Runtime.Serialization; using <[RootNamespace]>.HelperClasses; using <[RootNamespace]>.EntityClasses; using SD.LLBLGen.Pro.ORMSupportClasses; namespace <[RootNamespace]>.DTOClasses { <[ UserCodeRegion "AdditionalNamespaces" ]> // __LLBLGENPRO_USER_CODE_REGION_START AdditionalNamespaces // __LLBLGENPRO_USER_CODE_REGION_END <[ EndUserCodeRegion ]> /// <summary> /// DTO class for the entity '<[CurrentEntityName]>'. /// </summary> [Serializable] public <[If UsePartialClasses]>partial <[EndIf]>class <[CurrentEntityName]>DTO : <[ If IsSubType ]><[ SuperTypeName ]>DTO, <[ EndIf]>IDTO<<[CurrentEntityName]>Entity><[ UserCodeRegion "AdditionalInterfaces" ]> // __LLBLGENPRO_USER_CODE_REGION_START AdditionalInterfaces // __LLBLGENPRO_USER_CODE_REGION_END <[ EndUserCodeRegion ]> { #region Entity Field Public Properties <[Foreach EntityField CrLf]> /// <summary>Get or set the <[EntityFieldName]> property that maps to the Entity <[CurrentEntityName]></summary> public virtual <[If GenerateAsNullableType]><[TypeOfField]>?<[Else]><[TypeOfField]><[EndIf]> <[EntityFieldName]> { get; set; } <[NextForeach]> #endregion #region Related Field Public Properties <[ Foreach RelatedEntityField CrLf]> /// <summary>Get or set the <[MappedFieldNameRelatedField]> property that maps to the Entity <[CurrentEntityName]> <[ MappedFieldNameRelation ]>.<[ RelatedEntityFieldName ]></summary> public virtual <[If GenerateAsNullableType]><[TypeOfField]>?<[Else]><[TypeOfField]><[EndIf]> <[ MappedFieldNameRelatedField ]> { get; private set; }<[NextForeach]> #endregion #region Custom Fields <[ UserCodeRegion "CustomFieldCode" ]> // __LLBLGENPRO_USER_CODE_REGION_START CustomFieldCode // __LLBLGENPRO_USER_CODE_REGION_END <[ EndUserCodeRegion ]> #endregion #region Ctors /// <summary> /// CTor /// </summary> public <[CurrentEntityName]>DTO() { } /// <summary> /// CTor which initializes the DTO with values from its corresponding entity /// </summary> /// <param name="entityInstance">The entity instance which holds the values for this DTO</param> public <[CurrentEntityName]>DTO(<[CurrentEntityName]>Entity entityInstance) : this(entityInstance, new Hashtable(), new Hashtable()) { } internal <[CurrentEntityName]>DTO(<[CurrentEntityName]>Entity entityInstance, Hashtable seenObjects, Hashtable parents)<[ If IsSubType ]> : base(entityInstance, seenObjects, parents)<[ EndIf]> { FromEntity(entityInstance, seenObjects, parents); } #endregion /// <summary> /// Creates a <[CurrentEntityName]>DTO object from the given entity. /// </summary> public virtual IDTO<<[CurrentEntityName]>Entity> FromEntity(<[CurrentEntityName]>Entity entityInstance, Hashtable seenObjects, Hashtable parents) { <[ If IsSubType ]>base.FromEntity(entityInstance, seenObjects, parents); <[ EndIf]>seenObjects[entityInstance] = this; parents = new Hashtable(parents); parents.Add(entityInstance, null); <[Foreach EntityField CrLf]> this.<[EntityFieldName]> = entityInstance.<[EntityFieldName]>;<[NextForeach]> <[Foreach RelatedEntityField CrLf]> if (entityInstance.AlreadyFetched<[MappedFieldNameRelation]>) this.<[MappedFieldNameRelatedField]> = entityInstance.<[MappedFieldNameRelatedField]>;<[NextForeach]> <[Foreach RelatedEntity OneToMany CrLf]><[If Not MappedFieldRelationIsHidden]> if (entityInstance.AlreadyFetched<[MappedFieldNameRelation]>) <[MappedFieldNameRelation]> = RelatedArray<<[RelatedEntityName]>DTO, <[RelatedEntityName]>Entity>(entityInstance.<[MappedFieldNameRelation]>, seenObjects, parents);<[EndIf]><[NextForeach]> <[Foreach RelatedEntity ManyToMany CrLf]><[If Not MappedFieldRelationIsHidden]> if (entityInstance.AlreadyFetched<[MappedFieldNameRelation]>) <[MappedFieldNameRelation]> = RelatedArray<<[RelatedEntityName]>DTO, <[RelatedEntityName]>Entity>(entityInstance.<[MappedFieldNameRelation]>, seenObjects, parents);<[EndIf]><[NextForeach]> <[Foreach RelatedEntity ManyToOne CrLf]><[If Not MappedFieldRelationIsHidden]> if (entityInstance.AlreadyFetched<[MappedFieldNameRelation]>) <[MappedFieldNameRelation]> = RelatedObject<<[RelatedEntityName]>DTO, <[RelatedEntityName]>Entity>(entityInstance.<[MappedFieldNameRelation]>, seenObjects, parents);//(new <[RelatedEntityName]>DTO(entityInstance.<[MappedFieldNameRelation]>, seenObjects);<[EndIf]><[NextForeach]> <[Foreach RelatedEntity OneToOne CrLf]><[If Not MappedFieldRelationIsHidden]> if (entityInstance.AlreadyFetched<[MappedFieldNameRelation]>) <[MappedFieldNameRelation]> = RelatedObject<<[RelatedEntityName]>DTO, <[RelatedEntityName]>Entity>(entityInstance.<[MappedFieldNameRelation]>, seenObjects, parents);<[EndIf]><[NextForeach]> return this; } <[ If Not IsSubType ]> /// <summary> /// Get a collection of DTO objects created from entities related to <[CurrentEntityName]>Entity. /// It keeps track of entities previously seen to prevent an infinite loop. /// <summary> protected virtual T[] RelatedArray<T,U>(EntityCollectionBase<U> entities, Hashtable seenObjects, Hashtable parents) where T : class, IDTO<U>, new() where U : EntityBase { if (null == entities) { return null; } T[] arr = new T[entities.Count]; int i = 0; foreach (U entity in entities) { if (parents.Contains(entity)) { return null; } } foreach (U entity in entities) { if (seenObjects.Contains(entity)) { arr[i++] = seenObjects[entity] as T; } else { arr[i++] = new T().FromEntity(entity, seenObjects, parents) as T; } } return arr; } /// <summary> /// Creates a DTO object from the given related <[CurrentEntityName]>Entity entity. /// This is used to populate a single DTO from a single relation of the <[CurrentEntityName]>Entity. /// <summary> protected virtual T RelatedObject<T,U>(U entityInstance, Hashtable seenObjects, Hashtable parents) where T : class, IDTO<U>, new() where U : EntityBase { if (null == entityInstance) { return null; } if (seenObjects.Contains(entityInstance)) { if (parents.Contains(entityInstance)) { return null; } else { return seenObjects[entityInstance] as T; } } return new T().FromEntity(entityInstance, seenObjects, parents) as T; } <[ EndIf]> /// <summary> /// Get a collection of individual DTO objects from the EntityCollectionBase<<[CurrentEntityName]>Entity> collection. /// <summary> public static <[CurrentEntityName]>DTO[] ToDTOArray(EntityCollectionBase<<[CurrentEntityName]>Entity> entities) { Hashtable seenObjects = new Hashtable(); <[CurrentEntityName]>DTO[] arr = new <[CurrentEntityName]>DTO[entities.Count]; for (int i = 0; i < entities.Count; i++) { arr[i] = new <[CurrentEntityName]>DTO().FromEntity(entities[i], seenObjects, new Hashtable()) as <[CurrentEntityName]>DTO; } return arr; } /// <summary> /// Creates a new entity instance and copies over the values of this DTO /// </summary> public <[ If IsSubType ]>override <[SuperTypeName]><[ Else]>virtual <[CurrentEntityName]><[ EndIf]>Entity ToEntity() { return ToEntity(new <[CurrentEntityName]>Entity()); } /// <summary> /// Copies over the values of this DTO into the entity passed in. /// Readonly fields on the entity are NOT copied to the entity from this DTO. /// </summary> public virtual <[CurrentEntityName]>Entity ToEntity(<[CurrentEntityName]>Entity toFill) { <[Foreach EntityField CrLf]><[If IsReadOnly ]><[ Else ]> toFill.<[EntityFieldName]> = this.<[EntityFieldName]>;<[ EndIf ]><[NextForeach]> <[ If IsSubType ]> base.ToEntity(toFill);<[ EndIf]> return toFill; } #region Relation Fields <[Foreach RelatedEntity OneToMany CrLf]><[If Not MappedFieldRelationIsHidden]> /// <summary> Gets the EntityCollectionBase with the related entities of type '<[RelatedEntityName]>Entity' which are related to this entity via a relation of type '1:n'. /// If the EntityCollectionBase hasn't been fetched yet, the collection returned will be empty.</summary> public virtual <[RelatedEntityName]>DTO[] <[MappedFieldNameRelation]> { get; set; }<[EndIf]><[NextForeach]> <[Foreach RelatedEntity ManyToMany CrLf]><[If Not MappedFieldRelationIsHidden]> /// <summary> Gets the EntityCollectionBase with the related entities of type '<[RelatedEntityName]>Entity' which are related to this entity via a relation of type 'm:n'. /// If the EntityCollectionBase hasn't been fetched yet, the collection returned will be empty.</summary> public virtual <[RelatedEntityName]>DTO[] <[MappedFieldNameRelation]> { get; set; }<[EndIf]><[NextForeach]> <[Foreach RelatedEntity ManyToOne CrLf]><[If Not MappedFieldRelationIsHidden]> /// <summary> Gets / sets related entity of type '<[RelatedEntityName]>Entity' which has to be set using a fetch action earlier. If no related entity /// is set for this property, null is returned. This property is not visible in databound grids.</summary> [Browsable(false)] public virtual <[RelatedEntityName]>DTO <[MappedFieldNameRelation]> { get; set; }<[EndIf]><[NextForeach]> <[Foreach RelatedEntity OneToOne CrLf]><[If Not MappedFieldRelationIsHidden]> /// <summary> Gets / sets related entity of type '<[RelatedEntityName]>Entity' which has to be set using a fetch action earlier. If no related entity /// is set for this property, null is returned. This property is not visible in databound grids.</summary> [Browsable(false)] public virtual <[RelatedEntityName]>DTO <[MappedFieldNameRelation]> { get; set; }<[EndIf]><[NextForeach]> #endregion #region Custom DTO code <[ UserCodeRegion "CustomDTOCode" ]> // __LLBLGENPRO_USER_CODE_REGION_START CustomDTOCode // __LLBLGENPRO_USER_CODE_REGION_END <[ EndUserCodeRegion ]> #endregion } }

File: dtoExtensions.template

 using System; using System.Collections.Generic; using System.Linq; using <[RootNamespace]>; using <[RootNamespace]>.EntityClasses; using <[RootNamespace]>.CollectionClasses; using <[RootNamespace]>.DTOClasses; using <[RootNamespace]>.HelperClasses; namespace <[RootNamespace]>.DTOClasses { /// <summary> /// Generates extension methods for converting Entities to DTOs /// This class is generated. Do not modify. /// </summary> public static <[If UsePartialClasses]>partial <[EndIf]>class Extensions { <[If HasEntity]><[Foreach Entity]> /// <summary>Create a <[CurrentEntityName]> DTO from a <[CurrentEntityName]> entity</summary> /// <returns>The DTO created</returns> public static <[CurrentEntityName]>DTO ToDTO(this <[CurrentEntityName]>Entity entity) { <[CurrentEntityName]>DTO dto = null; if (entity != null) dto = new <[CurrentEntityName]>DTO(entity); return dto; } /// <summary>Create a list of <[CurrentEntityName]>DTO from a <[CurrentEntityName]>Collection</summary> /// <returns>The DTO list created</returns> public static List<<[CurrentEntityName]>DTO> ToDTOs(this <[CurrentEntityName]>Collection collection) { List<<[CurrentEntityName]>DTO> dtoList = new List<<[CurrentEntityName]>DTO>(collection.Count); foreach(<[CurrentEntityName]>Entity entity in collection) dtoList.Add(new <[CurrentEntityName]>DTO(entity)); return dtoList; } /// <summary>Create a list of <[CurrentEntityName]>DTO from a List of <[CurrentEntityName]> entities</summary> /// <returns>The DTO list created</returns> public static List<<[CurrentEntityName]>DTO> ToDTOs(this List<<[CurrentEntityName]>Entity> entities) { return entities.ConvertAll<<[CurrentEntityName]>DTO>(e => new <[CurrentEntityName]>DTO(e)); } /// <summary>From the queryable object, get a list of <[CurrentEntityName]>DTO</summary> /// <returns>The DTO list created</returns> public static List<<[CurrentEntityName]>DTO> ToDTOs(this IQueryable<<[CurrentEntityName]>Entity> queryableEntities) { return queryableEntities.ToList().ConvertAll<<[CurrentEntityName]>DTO>(e => new <[CurrentEntityName]>DTO(e)); } /// <summary>From the queryable object, get a list of <[CurrentEntityName]>DTO</summary> /// <returns>The DTO list created</returns> public static <[CurrentEntityName]>DTO FirstDTO(this IQueryable<<[CurrentEntityName]>Entity> queryableEntities) { <[CurrentEntityName]>DTO dto = null; <[CurrentEntityName]>Entity firstEntity = queryableEntities.First(); if (firstEntity != null) dto = new <[CurrentEntityName]>DTO(firstEntity); return dto; } <[NextForeach]><[EndIf]> #region Custom code <[ UserCodeRegion "CustomDTOCode" ]> // __LLBLGENPRO_USER_CODE_REGION_START CustomDTOCode // __LLBLGENPRO_USER_CODE_REGION_END <[ EndUserCodeRegion ]> #endregion } }

FILE: DTO.tasks

 <?xml version="1.0" ?> <taskGroup xmlns="http://sd/llblgen/pro/taskGroupElementDefinitions.xsd" name="DTO Templates" isOptional="false" description="General group of tasks which are used DTO templates."> <supportedPlatforms> <platform name=".NET 3.5" /> </supportedPlatforms> <supportedTemplateGroups> <templateGroup name="SelfServicing" /> </supportedTemplateGroups> <taskGroup name="Create Directories"> <task name="DTODirectoryCreator" assemblyFilename="SD.LLBLGen.Pro.TaskPerformers.dll" taskPerformerClass="SD.LLBLGen.Pro.TaskPerformers.DirectoryCreator"> <parameters> <parameter name="folderToCreate" defaultValue="DTOClasses" isOptional="false" description="The folder to create" /> <parameter name="failWhenExistent" defaultValue="false" isOptional="true" description="Flag to signal what to do when the folder already exists. Overrules clearWhenExistent" valueType="boolean" /> <parameter name="clearWhenExistent" defaultValue="false" isOptional="true" description="Flag to signal if an existing folder has to be cleared first. Overruled by failWhenExistent" valueType="boolean" /> </parameters> </task> </taskGroup> <taskGroup name="Create DTO Classes" description="Create DTO Classes"> <task name="DTOInterfaceCreator" assemblyFilename="SD.LLBLGen.Pro.TaskPerformers.dll" taskPerformerClass="SD.LLBLGen.Pro.TaskPerformers.CodeEmitter"> <parameters> <parameter isOptional="false" name="destinationFolder" defaultValue="DTOClasses" /> <parameter isOptional="false" name="failWhenExistent" defaultValue="false" /> <parameter isOptional="false" name="filenameFormat" defaultValue="IDTO.cs" /> <parameter isOptional="false" name="templateID" defaultValue="SD_DTOInterfaceTemplate" /> <parameter isOptional="false" name="emitType" defaultValue="generic" /> </parameters> </task> <task name="DTOClassCreator" assemblyFilename="SD.LLBLGen.Pro.TaskPerformers.dll" taskPerformerClass="SD.LLBLGen.Pro.TaskPerformers.CodeEmitter"> <parameters> <parameter isOptional="false" name="destinationFolder" defaultValue="DTOClasses" /> <parameter isOptional="false" name="failWhenExistent" defaultValue="false" /> <parameter isOptional="false" name="filenameFormat" defaultValue="[elementName]DTO.[extension]" /> <parameter isOptional="false" name="templateID" defaultValue="SD_DTOTemplate" /> <parameter isOptional="false" name="emitType" defaultValue="allEntities" /> </parameters> </task> <task name="DTOExtentionsCreator" assemblyFilename="SD.LLBLGen.Pro.TaskPerformers.dll" taskPerformerClass="SD.LLBLGen.Pro.TaskPerformers.CodeEmitter"> <parameters> <parameter isOptional="false" name="destinationFolder" defaultValue="DTOClasses" /> <parameter isOptional="false" name="failWhenExistent" defaultValue="false" /> <parameter isOptional="false" name="filenameFormat" defaultValue="DTOExtensions.cs" /> <parameter isOptional="false" name="templateID" defaultValue="SD_DTOExtentionsTemplate" /> <parameter isOptional="false" name="emitType" defaultValue="generic" /> </parameters> </task> </taskGroup> </taskGroup>

Finally add the following to the appropriate location in the * .preset file. This will define the task of generating the code above within your predefined generation.

 <taskGroupPreset name="DTO Templates"> <taskGroupPreset name="Create Directories"> <taskPreset name="DTODirectoryCreator" /> </taskGroupPreset> <taskGroupPreset name="Create DTO Classes"> <taskPreset name="DTOInterfaceCreator" /> <taskPreset name="DTOEntityInterfaceCreator" /> <taskPreset name="DTOBaseClassCreator" /> <taskPreset name="DTOClassCreator" /> <taskPreset name="DTOExtentionsCreator" /> </taskGroupPreset> </taskGroupPreset>
+6
source

Source: https://habr.com/ru/post/900183/

More articles:


All Articles