Блог

Главная - Вопросы по программированию - T4 для генерации POCO поверх объектов LLBLGen Pro?

T4 для генерации POCO поверх объектов LLBLGen Pro?

#.net #orm #poco #t4 #llblgenpro

#.net #orm #poco #t4 #llblgenpro

Вопрос:

Насколько я понимаю, LLBLGen Pro не может генерировать POCO поверх своих собственных объектов (см. Здесь: http://www.llblgen.com/Pages/featuresLLBLGenPro.aspx ).

Кто-нибудь написал T4, который будет генерировать классы POCO, соответствующие объектам LLBLGen Pro, и генерировать соответствующую логику преобразования для перехода к сущности и POCO и обратно? Кто-нибудь еще придумал решение, которое не требует ручного написания тонны кода преобразования?

Комментарии:

1. Хотя я не создал именно то, что вы не хотите, создание шаблонов T4 на самом деле не будет таким сложным, если вы используете template studio, которую можно загрузить с сайта llblgen. Я создал шаблон, который будет генерировать sp для выполнения репликации вручную (не спрашивайте!), И то, что вам нужно сделать, намного проще. Для сопоставления вы могли бы просто использовать AutoMapper. Что вы пытаетесь получить, используя POCO?

2. Спасибо пещерный человек. То, что мы хотим получить, используя POCOs, выходит за рамки вопроса, но сам по себе хороший вопрос. Помимо причин, я определенно считаю, что это возможно сделать, но я надеялся, что у кого-то уже есть T4, созданный и общедоступный.

Ответ №1:

Мы сгенерировали DTO из LLBLGen, а не с помощью T4.

Нам нужно было создать DTO из объекта. Технически это не POCO, потому что у них есть ToEntity() FromEntity() метод and , но, возможно, это сработает для вас.

Мы создали IDTO<T> интерфейс, который затем был реализован классами DTO (по одному для каждой сущности). Вместо изменения шаблонов объектов мы добавили DTOExtension методы, которые преобразуют объект в DTO (а также множество других вспомогательных преобразований).

Вот файлы шаблонов, которые вы можете использовать в LLBLGen версии v2.6. Конструктор шаблонов в версии 3 намного проще в использовании, и вы можете преобразовать большую часть этого кода для версии 3, если вам нужно.

Файл: 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);
    }
}

Файл: 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]>'s <[ 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
    }
}

Файл: 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
    }
}

ФАЙЛ: 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>

Наконец, добавьте следующее в соответствующее место в вашем файле *.preset . Это определит задачу генерации кода выше в вашей предустановке генерации.

 <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>
Метки: