六、Abp vNext 基础篇丨文章聚合功能上
时间：2022-09-23
系列文章列表，点击展示/隐藏
系列教程一目录：知识点源码解析
系列教程二目录：Bcvp AbpVnext讲解
系列教程三目录：单个知识点讲解
系列教程四目录：分库分表(日志系统案例讲解)
本文梯子
正文
介绍
9月开篇讲，前面几章群里已经有几个小伙伴跟着做了一遍了，遇到的问题和疑惑也都在群里反馈和解决好了，9月咱们保持保持更新。争取10月份更新完基础篇。
另外番外篇属于 我在abp群里和日常开发的问题记录，如果各位在使用abp的过程中发现什么问题也可以及时反馈给我。
上一章已经把所有实体的迁移都做好了，这一章我们进入到文章聚合，文章聚合涉及接口比较多。
开工
先来看下需要定义那些应用层接口,Dto我也在下面定义好了，关于里面的BlogUserDto这个是作者目前打算采用ABP Identtiy中的User来做到时候通过权限控制，另外就是TagDto属于Posts领域的Dto.
public interface IPostAppService : IApplicationService
{
Task<ListResultDto<PostWithDetailsDto>> GetListByBlogIdAndTagName(Guid blogId, string tagName);
Task<ListResultDto<PostWithDetailsDto>> GetTimeOrderedListAsync(Guid blogId);
Task<PostWithDetailsDto> GetForReadingAsync(GetPostInput input);
Task<PostWithDetailsDto> GetAsync(Guid id);
Task DeleteAsync(Guid id);
Task<PostWithDetailsDto> CreateAsync(CreatePostDto input);
Task<PostWithDetailsDto> UpdateAsync(Guid id, UpdatePostDto input);
}
public >BlogUserDto : EntityDto<Guid>
{
public Guid? TenantId { get; set; }
public string UserName { get; set; }
public string Email { get; set; }
public bool EmailConfirmed { get; set; }
public string PhoneNumber { get; set; }
public bool PhoneNumberConfirmed { get; set; }
public Dictionary<string, object> ExtraProperties { get; set; }
}
public >CreatePostDto
{
public Guid BlogId { get; set; }
[Required]
[DynamicStringLength(typeof(PostConsts), nameof(PostConsts.MaxTitleLength))]
public string Title { get; set; }
[Required]
public string CoverImage { get; set; }
[Required]
[DynamicStringLength(typeof(PostConsts), nameof(PostConsts.MaxUrlLength))]
public string Url { get; set; }
[Required]
[DynamicStringLength(typeof(PostConsts), nameof(PostConsts.MaxContentLength))]
public string Content { get; set; }
public string Tags { get; set; }
[DynamicStringLength(typeof(PostConsts), nameof(PostConsts.MaxDescriptionLength))]
public string Description { get; set; }
}
public >GetPostInput
{
[Required]
public string Url { get; set; }
public Guid BlogId { get; set; }
}
public >UpdatePostDto
{
public Guid BlogId { get; set; }
[Required]
public string Title { get; set; }
[Required]
public string CoverImage { get; set; }
[Required]
public string Url { get; set; }
[Required]
public string Content { get; set; }
public string Description { get; set; }
public string Tags { get; set; }
}
public >PostWithDetailsDto : FullAuditedEntityDto<Guid>
{
public Guid BlogId { get; set; }
public string Title { get; set; }
public string CoverImage { get; set; }
public string Url { get; set; }
public string Content { get; set; }
public string Description { get; set; }
public int ReadCount { get; set; }
public int CommentCount { get; set; }
[CanBeNull]
public BlogUserDto Writer { get; set; }
public List<TagDto> Tags { get; set; }
}
public >TagDto : FullAuditedEntityDto<Guid>
{
public string Name { get; set; }
public string Description { get; set; }
public int UsageCount { get; set; }
}
根据上上面的接口我想，就应该明白ABP自带的仓储无法满足我们业务需求，我们需要自定义仓储,在大多数场景下我们不会采用ABP提供的泛型仓储，除非业务足够简单泛型仓储完全满足(个人意见)。
另外我们重写了WithDetailsAsync通过扩展IncludeDetails方法实现Include包含⼦集合对象，其实这个也可以作为可选参数我们可以在使用ABP提供的泛型仓储GetAsync方法中看到他有一个可选参数includeDetails,来指明查询是否包含⼦集合对象。
public interface IPostRepository : IBasicRepository<Post, Guid>
{
Task<List<Post>> GetPostsByBlogId(Guid id, CancellationToken cancellationToken = default);
Task<bool> IsPostUrlInUseAsync(Guid blogId, string url, Guid? excludingPostId = null, CancellationToken cancellationToken = default);
Task<Post> GetPostByUrl(Guid blogId, string url, CancellationToken cancellationToken = default);
Task<List<Post>> GetOrderedList(Guid blogId, bool descending = false, CancellationToken cancellationToken = default);
}
public >EfCorePostRepository : EfCoreRepository<CoreDbContext, Post, Guid>, IPostRepository
{
public EfCorePostRepository(IDbContextProvider<CoreDbContext> dbContextProvider)
: base(dbContextProvider)
{
}
public async Task<List<Post>> GetPostsByBlogId(Guid id, CancellationToken cancellationToken = default)
{
return await (await GetDbSetAsync()).Where(p => p.BlogId == id).OrderByDescending(p => p.CreationTime).ToListAsync(GetCancellationToken(cancellationToken));
}
public async Task<bool> IsPostUrlInUseAsync(Guid blogId, string url, Guid? excludingPostId = null, CancellationToken cancellationToken = default)
{
var query = (await GetDbSetAsync()).Where(p => blogId == p.BlogId && p.Url == url);
if (excludingPostId != null)
{
query = query.Where(p => excludingPostId != p.Id);
}
return await query.AnyAsync(GetCancellationToken(cancellationToken));
}
public async Task<Post> GetPostByUrl(Guid blogId, string url, CancellationToken cancellationToken = default)
{
var post = await (await GetDbSetAsync()).FirstOrDefaultAsync(p => p.BlogId == blogId && p.Url == url, GetCancellationToken(cancellationToken));
if (post == null)
{
throw new EntityNotFoundException(typeof(Post), nameof(post));
}
return post;
}
public async Task<List<Post>> GetOrderedList(Guid blogId, bool descending = false, CancellationToken cancellationToken = default)
{
if (!descending)
{
return await (await GetDbSetAsync()).Where(x => x.BlogId == blogId).OrderByDescending(x => x.CreationTime).ToListAsync(GetCancellationToken(cancellationToken));
}
else
{
return await (await GetDbSetAsync()).Where(x => x.BlogId == blogId).OrderBy(x => x.CreationTime).ToListAsync(GetCancellationToken(cancellationToken));
}
}
public override async Task<IQueryable<Post>> WithDetailsAsync()
{
return (await GetQueryableAsync()).IncludeDetails();
}
}
public static >CoreEntityFrameworkCoreQueryableExtensions
{
public static IQueryable<Post> IncludeDetails(this IQueryable<Post> queryable, bool include = true)
{
if (!include)
{
return queryable;
}
return queryable
.Include(x => x.Tags);
}
}
应用层
新建PostAppService继承IPostAppService然后开始第一个方法GetListByBlogIdAndTagName该方法根据blogId 和 tagName 查询相关的文章数据。我们有IPostRepository的GetPostsByBlogId方法可以根据blogId获取文章，那么如何在根据tagName筛选呢，这里就需要我们新增一个ITagRepository,先不着急先实现先把业务逻辑跑通。
public interface ITagRepository : IBasicRepository<Tag, Guid>
{
Task<List<Tag>> GetListAsync(Guid blogId, CancellationToken cancellationToken = default);
Task<Tag> FindByNameAsync(Guid blogId, string name, CancellationToken cancellationToken = default);
Task<List<Tag>> GetListAsync(IEnumerable<Guid> ids, CancellationToken cancellationToken = default);
}
现在进行下一步，文章已经查询出来了，文章上的作者和Tag还没处理，下面代码我写了注释代码意思应该都能看明白，这里可能会比较疑问的事这样写代码for循环去跑数据库是不是不太合理，因为Tags这个本身就不会存在很多数据，这块如果要调整其实完全可以讲TagName存在Tasg值对象中。
public async Task<ListResultDto<PostWithDetailsDto>> GetListByBlogIdAndTagName(Guid id, string tagName)
{
// 根据blogId查询文章数据
var posts = await _postRepository.GetPostsByBlogId(id);
var postDtos = new List<PostWithDetailsDto>(ObjectMapper.Map<List<Post>, List<PostWithDetailsDto>>(posts));
// 根据tagName筛选tag
var tag = tagName.IsNullOrWhiteSpace() ? null : await _tagRepository.FindByNameAsync(id, tagName);
// 给文章Tags赋值
foreach (var postDto in postDtos)
{
postDto.Tags = await GetTagsOfPost(postDto.Id);
}
// 筛选掉不符合要求的文章
if (tag != null)
{
postDtos = await FilterPostsByTag(postDtos, tag);
}
}
private async Task<List<TagDto>> GetTagsOfPost(Guid id)
{
var tagIds = (await _postRepository.GetAsync(id)).Tags;
var tags = await _tagRepository.GetListAsync(tagIds.Select(t => t.TagId));
return ObjectMapper.Map<List<Tag>, List<TagDto>>(tags);
}
private Task<List<PostWithDetailsDto>> FilterPostsByTag(IEnumerable<PostWithDetailsDto> allPostDtos, Tag tag)
{
var filteredPostDtos = allPostDtos.Where(p => p.Tags?.Any(t => t.Id == tag.Id) ?? false).ToList();
return Task.FromResult(filteredPostDtos);
}
继续向下就是赋值作者信息，对应上面Tasg最多十几个，但是系统有多少用户就不好说了所以这里使用userDictionary就是省掉重复查询数据。
public async Task<ListResultDto<PostWithDetailsDto>> GetListByBlogIdAndTagName(Guid id, string tagName)
{
// 前面的代码就不重复粘贴了
var userDictionary = new Dictionary<Guid, BlogUserDto>();
// 赋值作者信息
foreach (var postDto in postDtos)
{
if (postDto.CreatorId.HasValue)
{
if (!userDictionary.ContainsKey(postDto.CreatorId.Value))
{
var creatorUser = await UserLookupService.FindByIdAsync(postDto.CreatorId.Value);
if (creatorUser != null)
{
userDictionary[creatorUser.Id] = ObjectMapper.Map<BlogUser, BlogUserDto>(creatorUser);
}
}
if (userDictionary.ContainsKey(postDto.CreatorId.Value))
{
postDto.Writer = userDictionary[(Guid)postDto.CreatorId];
}
}
}
return new ListResultDto<PostWithDetailsDto>(postDtos);
}
目前删除和修改接口做不了因为这里牵扯评论的部分操作，除去这两个，其他的接口直接看代码应该都没有什么问题，这一章的东西已经很多了剩下的我们下集。
public async Task<ListResultDto<PostWithDetailsDto>> GetListByBlogIdAndTagName(Guid id, string tagName)
{
// 根据blogId查询文章数据
var posts = await _postRepository.GetPostsByBlogId(id);
// 根据tagName筛选tag
var tag = tagName.IsNullOrWhiteSpace() ? null : await _tagRepository.FindByNameAsync(id, tagName);
var userDictionary = new Dictionary<Guid, BlogUserDto>();
var postDtos = new List<PostWithDetailsDto>(ObjectMapper.Map<List<Post>, List<PostWithDetailsDto>>(posts));
// 给文章Tags赋值
foreach (var postDto in postDtos)
{
postDto.Tags = await GetTagsOfPost(postDto.Id);
}
// 筛选掉不符合要求的文章
if (tag != null)
{
postDtos = await FilterPostsByTag(postDtos, tag);
}
// 赋值作者信息
foreach (var postDto in postDtos)
{
if (postDto.CreatorId.HasValue)
{
if (!userDictionary.ContainsKey(postDto.CreatorId.Value))
{
var creatorUser = await UserLookupService.FindByIdAsync(postDto.CreatorId.Value);
if (creatorUser != null)
{
userDictionary[creatorUser.Id] = ObjectMapper.Map<IdentityUser, BlogUserDto>(creatorUser);
}
}
if (userDictionary.ContainsKey(postDto.CreatorId.Value))
{
postDto.Writer = userDictionary[(Guid)postDto.CreatorId];
}
}
}
return new ListResultDto<PostWithDetailsDto>(postDtos);
}
public async Task<ListResultDto<PostWithDetailsDto>> GetTimeOrderedListAsync(Guid blogId)
{
var posts = await _postRepository.GetOrderedList(blogId);
var postsWithDetails = ObjectMapper.Map<List<Post>, List<PostWithDetailsDto>>(posts);
foreach (var post in postsWithDetails)
{
if (post.CreatorId.HasValue)
{
var creatorUser = await UserLookupService.FindByIdAsync(post.CreatorId.Value);
if (creatorUser != null)
{
post.Writer = ObjectMapper.Map<IdentityUser, BlogUserDto>(creatorUser);
}
}
}
return new ListResultDto<PostWithDetailsDto>(postsWithDetails);
}
public async Task<PostWithDetailsDto> GetForReadingAsync(GetPostInput input)
{
var post = await _postRepository.GetPostByUrl(input.BlogId, input.Url);
post.IncreaseReadCount();
var postDto = ObjectMapper.Map<Post, PostWithDetailsDto>(post);
postDto.Tags = await GetTagsOfPost(postDto.Id);
if (postDto.CreatorId.HasValue)
{
var creatorUser = await UserLookupService.FindByIdAsync(postDto.CreatorId.Value);
postDto.Writer = ObjectMapper.Map<IdentityUser, BlogUserDto>(creatorUser);
}
return postDto;
}
public async Task<PostWithDetailsDto> GetAsync(Guid id)
{
var post = await _postRepository.GetAsync(id);
var postDto = ObjectMapper.Map<Post, PostWithDetailsDto>(post);
postDto.Tags = await GetTagsOfPost(postDto.Id);
if (postDto.CreatorId.HasValue)
{
var creatorUser = await UserLookupService.FindByIdAsync(postDto.CreatorId.Value);
postDto.Writer = ObjectMapper.Map<IdentityUser, BlogUserDto>(creatorUser);
}
return postDto;
}
public async Task<PostWithDetailsDto> CreateAsync(CreatePostDto input)
{
input.Url = await RenameUrlIfItAlreadyExistAsync(input.BlogId, input.Url);
var post = new Post(
id: GuidGenerator.Create(),
blogId: input.BlogId,
title: input.Title,
coverImage: input.CoverImage,
url: input.Url
)
{
Content = input.Content,
Description = input.Description
};
await _postRepository.InsertAsync(post);
var tagList = SplitTags(input.Tags);
await SaveTags(tagList, post);
return ObjectMapper.Map<Post, PostWithDetailsDto>(post);
}
private async Task<string> RenameUrlIfItAlreadyExistAsync(Guid blogId, string url, Post existingPost = null)
{
if (await _postRepository.IsPostUrlInUseAsync(blogId, url, existingPost?.Id))
{
return url + "-" + Guid.NewGuid().ToString().Substring(0, 5);
}
return url;
}
private async Task SaveTags(ICollection<string> newTags, Post post)
{
await RemoveOldTags(newTags, post);
await AddNewTags(newTags, post);
}
private async Task RemoveOldTags(ICollection<string> newTags, Post post)
{
foreach (var oldTag in post.Tags.ToList())
{
var tag = await _tagRepository.GetAsync(oldTag.TagId);
var oldTagNameInNewTags = newTags.FirstOrDefault(t => t == tag.Name);
if (oldTagNameInNewTags == null)
{
post.RemoveTag(oldTag.TagId);
tag.DecreaseUsageCount();
await _tagRepository.UpdateAsync(tag);
}
else
{
newTags.Remove(oldTagNameInNewTags);
}
}
}
private async Task AddNewTags(IEnumerable<string> newTags, Post post)
{
var tags = await _tagRepository.GetListAsync(post.BlogId);
foreach (var newTag in newTags)
{
var tag = tags.FirstOrDefault(t => t.Name == newTag);
if (tag == null)
{
tag = await _tagRepository.InsertAsync(new Tag(GuidGenerator.Create(), post.BlogId, newTag, 1));
}
else
{
tag.IncreaseUsageCount();
tag = await _tagRepository.UpdateAsync(tag);
}
post.AddTag(tag.Id);
}
}
private List<string> SplitTags(string tags)
{
if (tags.IsNullOrWhiteSpace())
{
return new List<string>();
}
return new List<string>(tags.Split(",").Select(t => t.Trim()));
}
private async Task<List<TagDto>> GetTagsOfPost(Guid id)
{
var tagIds = (await _postRepository.GetAsync(id)).Tags;
var tags = await _tagRepository.GetListAsync(tagIds.Select(t => t.TagId));
return ObjectMapper.Map<List<Tag>, List<TagDto>>(tags);
}
private Task<List<PostWithDetailsDto>> FilterPostsByTag(IEnumerable<PostWithDetailsDto> allPostDtos, Tag tag)
{
var filteredPostDtos = allPostDtos.Where(p => p.Tags?.Any(t => t.Id == tag.Id) ?? false).ToList();
return Task.FromResult(filteredPostDtos);
}
结语
本节知识点：
- 1.我们梳理了一个聚合的开发过程
因为该聚合东西太多了我们就拆成2章来搞一章的话太长了
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