automapper conditional Custom Value Resolver

Question

Is it possible to use a custom value resolver in automapper only if a certain condition is met?

In my case I only want to update the value with the custom value resolver if the destination is not null.

This is an example of my code. Basically I need to add the condition onto this. Is it possible?

Mapper.CreateMap<ResponseXml, MyModel>()
    .ForMember(dest => dest.FirstName, 
                 op => op.ResolveUsing<ResponseXmlValueResolver>()
                .FromMember(x => x.data.FirstOrDefault(y => y.name == "name")))

would this help? http://stackoverflow.com/questions/17822882/how-to-configure-conditional-mapping-in-automapper — Ric, Nov 18 '14 at 11:08

an phu · Answer 1 · 2018-04-20T00:10:09.723

1

I think Eris' solution would have work; It was just grammatical errors.

Mapper.CreateMap<ResponseXml, MyModel>()
    .ForMember(dest => dest.FirstName, 
             op => {
                    op.Condition(src => src != null);
                    op.ResolveUsing<ResponseXmlValueResolver>();
                      .FromMember(x => x.data.FirstOrDefault(y => y.name == "name"));
             });

Is this what you wanted?
If the destination is null, the mapping will be ignore.
If the destination is null, the mapping (with the customer resolved) will be apply.

edited Apr 20 '18 at 00:10

answered Apr 19 '18 at 23:47

an phu

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10

This is not correct because conditions are evaluated *AFTER* resolving value as stated here https://github.com/AutoMapper/AutoMapper/wiki/Resolvers-and-conditions – A77 Aug 24 '22 at 18:42

score 0 · Answer 2 · answered Aug 24 '22 at 19:37

As Conditions are evaluated after resolving member, like it's said here, none of the previous answers are correct. You should rather use PreCondition this way:

Mapper.CreateMap<ResponseXml, MyModel>()
.ForMember(dest => dest.FirstName, 
         op => {
                op.PreCondition(src => src != null);
                op.ResolveUsing<ResponseXmlValueResolver>();
                  .FromMember(x => x.data.FirstOrDefault(y => y.name == "name"));
         });

score -1 · Answer 3 · answered Nov 28 '14 at 19:40

Will this work? (I don't have a windows box in front of me at the moment)

Mapper.CreateMap<ResponseXml, MyModel>()
    .ForMember(dest => dest.FirstName, 
             op => op.Condition(src => src != null)
                     .ResolveUsing<ResponseXmlValueResolver>()
                     .FromMember(x => x.data.FirstOrDefault(y => y.name == "name")))

automapper conditional Custom Value Resolver

3 Answers3