OData

MagicMapper extentions for mapping expressions (OData)

To use, configure using the configuration helper method:

varmapper=newMapper(newMapperConfiguration(cfg =>{cfg.AddExpressionMapping();// Rest of your configuration}));// or if using the MS Ext DI:services.AddAutoMapper(cfg =>{cfg.AddExpressionMapping();},/* assemblies with profiles */);

DTO Queries

Expression Mapping also supports writing queries against the mapped objects. Take the following source and destination types:

publicclassUser{publicintId{get;set;}publicstringName{get;set;}}publicclassRequest{publicintId{get;set;}publicintAssigneeId{get;set;}publicUserAssignee{get;set;}}publicclassUserDTO{publicintId{get;set;}publicstringName{get;set;}}publicclassRequestDTO{publicintId{get;set;}publicUserDTOAssignee{get;set;}}

We can write LINQ expressions against the DTO collections.

ICollection<RequestDTO>requests=awaitcontext.Request.GetItemsAsync(mapper, r =>r.Id>0&&r.Id<3,null,newList<Expression<Func<IQueryable<RequestDTO>,IIncludableQueryable<RequestDTO,object>>>>(){ item =>item.Include(s =>s.Assignee)});ICollection<UserDTO>users=awaitcontext.User.GetItemsAsync<UserDTO,User>(mapper, u =>u.Id>0&&u.Id<4, q =>q.OrderBy(u =>u.Name));intcount=awaitcontext.Request.Query<RequestDTO,Request,int,int>(mapper, q =>q.Count(r =>r.Id>1));

The methods below map the DTO query expresions to the equivalent data query expressions. The call to IMapper.Map converts the data query results back to the DTO (or model) object types.

staticclassExtensions{internalstaticasyncTask<TModelResult>Query<TModel,TData,TModelResult,TDataResult>(thisIQueryable<TData>query,IMappermapper,Expression<Func<IQueryable<TModel>,TModelResult>>queryFunc)whereTData:class{//Map the expressionsFunc<IQueryable<TData>,TDataResult>mappedQueryFunc=mapper.MapExpression<Expression<Func<IQueryable<TData>,TDataResult>>>(queryFunc).Compile();//execute the queryreturnmapper.Map<TDataResult,TModelResult>(mappedQueryFunc(query));}internalstaticasyncTask<ICollection<TModel>>GetItemsAsync<TModel,TData>(thisIQueryable<TData>query,IMappermapper,Expression<Func<TModel,bool>>filter=null,Expression<Func<IQueryable<TModel>,IQueryable<TModel>>>queryFunc=null,ICollection<Expression<Func<IQueryable<TModel>,IIncludableQueryable<TModel,object>>>>includeProperties=null){//Map the expressionsExpression<Func<TData,bool>>f=mapper.MapExpression<Expression<Func<TData,bool>>>(filter);Func<IQueryable<TData>,IQueryable<TData>>mappedQueryFunc=mapper.MapExpression<Expression<Func<IQueryable<TData>,IQueryable<TData>>>>(queryFunc)?.Compile();ICollection<Expression<Func<IQueryable<TData>,IIncludableQueryable<TData,object>>>>includes=mapper.MapIncludesList<Expression<Func<IQueryable<TData>,IIncludableQueryable<TData,object>>>>(includeProperties);if(f!=null)query=query.Where(f);if(includes!=null)query=includes.Select(i =>i.Compile()).Aggregate(query,(list,next)=>query=next(query));//Call the storeICollection<TData>result=mappedQueryFunc!=null?awaitmappedQueryFunc(query).ToListAsync():awaitquery.ToListAsync();//Map and return the datareturnmapper.Map<IEnumerable<TData>,IEnumerable<TModel>>(result).ToList();}}