CODEWITHSUNDEEP
c#automapper
tinker
tinker

Reputation: 3424

AutoMapper and manually mapping nested complex types

I have complex data, that is returned from my API as follows:

"id": 1002,
"user_id": "98fd8f37-383d-4fe7-9b88-18cc8a8cd9bf",
"organization_id": null,
"content": "A post with a hashtag!",
"created_at": "2018-05-25T21:35:31.5218467",
"modified_at": "2018-05-25T21:35:31.5218467",
"can_comment": true,
"can_share": true,
"post_tags": [
    {
        "post_id": 1002,
        "tag_id": 1,
        "tag": {
            "id": 1,
            "value": "hashtag",
            "post_tags": []
        }
    }
]

That corresponds to my Post.cs entity, and I created new model class to map it with, which looks like this:

public class PostModel
{
    public int Id { get; set; }

    [Required]
    public string UserId { get; set; }

    public int? OrganizationId { get; set; }

    [Required]
    public string Content { get; set; }

    public DateTime CreatedAt { get; set; }

    public DateTime ModifiedAt { get; set; }

    public bool CanComment { get; set; } = true;

    public bool CanShare { get; set; } = true;

    public List<Tag> Tags { get; set; }
}

Where my Tag.cs and TagModel.cs classes lookk like this:

Tag.cs:

public class Tag
{
    [Key]
    [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }

    public string Value { get; set; }

    public ICollection<PostTag> PostTags { get; set; } = new List<PostTag>();
}

TagModel.cs:

public int Id { get; set; }

[Required]
public string Value { get; set; }

So, basically, I have a mapping as 

CreateMap<Post, PostModel>()
    .ReverseMap();
CreateMap<Tag, TagModel>()
    .ReverseMap();

but what I get from the API once I do the mapping is this:

"id": 1002,
"user_id": "98fd8f37-383d-4fe7-9b88-18cc8a8cd9bf",
"organization_id": null,
"content": "Finally a post with a hashtag!",
"created_at": "2018-05-25T21:35:31.5218467",
"modified_at": "2018-05-25T21:35:31.5218467",
"can_comment": true,
"can_share": true,
"tags": null

So, as you can see the Tags is not mapped. The reason is more likely that I have a many-to-many relationship between Post and Tag, and I originally get PostTags from the API. How can I tell AutoMapper to map the tag inside post_tags to the corresponding tag inside PostModel?

Upvotes: 1

Views: 590

Answers (1)

vCillusion
vCillusion

Reputation: 1799

AutoMapper maps the collection, not the objects in that collection, individually. So, first ignore the collection and then handle it manually.

// Map the Post and ignore the Tags
AutoMapper.Mapper.CreateMap<Post, PostModel>()
.ForMember(dest => dest.Tags,
           opts => opts.Ignore());

// Map the Tags and ignore the post_tags
AutoMapper.Mapper.CreateMap<Tag, TagModel>()
.ForMember(dest => dest.post_tags,
           opts => opts.Ignore());

// Map the Post Model
AutoMapper.Mapper.Map(post, postModel);

// Map the tags
for (int i = 0; i < post.post_tags.Count(); i++)
{
    AutoMapper.Mapper.Map(post.post_tags[i], postModel.Tags[i]);
}

Upvotes: 2

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