c# - How to use the new IValueResolver of AutoMapper? -

i @ loss how use new ivalueresolver interface in new version of automapper. perhaps used them improperly in previous versions of automapper...

i have lot of model classes, of them generated several databases on several database servers, using sqlmetal.

some of these classes has string property, publicationcode, identifies publication subscription, or offer, or invoice, or whatever is, belongs to.

the publication can exist in either of 2 systems (the old , new system), hence have bool property on destination model classes tells whether publication in old or new system.

using old version (<5?) of automapper, used valueresolver<string, bool> took publicationcode input parameter, , returned bool indicating location of publication (old or new system).

with new version (5+?) of automapper, seems no longer possible. new ivalueresolver requires unique implementation of each , every combination of source , destination models have, src.publicationcode needs resolved dst.isinnewsystem.

am trying use value resolvers in wrong way? there better way? main reason use resolver prefer have services injected constructor, , not having use dependencyresolver , in code (i'm using autofac).

currently, use in following way:

// class linq-to-sql, non-related properties removed. public class findcustomerserviceselloffers {     public string publicationcode { get; set; } } 

this 1 of several data model classes have, contains publicationcode property). particular class mapped view model:

public class salespitchviewmodel {     public bool isinnewsystem { get; set; } } 

the mapping definition these 2 classes (where expression iprofileexpression), non-related mappings removed:

expression.createmap<findcustomerserviceselloffers, salespitchviewmodel>()           .formember(d => d.isinnewsystem, o => o.resolveusing<publicationsystemresolver>().frommember(s => s.publicationcode)); 

and resolver:

public class publicationsystemresolver : valueresolver<string, bool> {     private readonly publicationservice _publicationservice;     public publicationsystemresolver(publicationservice publicationservice)     {         _publicationservice = publicationservice;     }      protected override bool resolvecore(string publicationcode)     {         return _publicationservice.isinnewsystem(publicationcode);     } } 

and use of mapper:

var result = context.findcustomerserviceselloffers.where(o => somecriteria).select(_mapper.map<salespitchviewmodel>).tolist(); 

you can create more general value resolver implementing imembervalueresolver<object, object, string, bool> , using in mapping configuration. can provide source property resolution function before:

public class publicationsystemresolver : imembervalueresolver<object, object, string, bool> {     private readonly publicationservice _publicationservice;      public publicationsystemresolver(publicationservice publicationservice)     {         this._publicationservice = publicationservice;     }      public bool resolve(object source, object destination, string sourcemember, bool destmember, resolutioncontext context)     {         return _publicationservice.isinnewsystem(sourcemember);     } }    cfg.createmap<findcustomerserviceselloffers, salespitchviewmodel>()     .formember(dest => dest.isinnewsystem,         src => src.resolveusing<publicationsystemresolver, string>(s => s.publicationcode));