DXA Java Model mapping issue

Question

We have a view model with a property as a multi valued Linked Component (Linked to a single Schema). We have created the models like:

@SemanticEntity(entityName = "schemarootname", vocabulary = SDL_CORE, prefix = "", public_ = true)
public class MainModel extends AbstractEntityModel {

    private String title;

    private List<componentlinkedmodalclass> items;

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

    public List<componentlinkedmodalclass> getItems() {
        return items;
    }

    public void setItems(List<componentlinkedmodalclass> items) {
        this.items = items;
    }

}

@SemanticEntity(entityName = "schemarootname1", vocabulary = SDL_CORE, prefix = "", public_ = true)
public class componentlinkedmodalclass extends AbstractEntityModel {

    private String title;


    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }

}

Get and Set method is defined in the model. In the schemas.json file I can see semantic definition for main schemas like:

{
    "Id": 36661,
    "RootElement": "schemarootname",
    "Fields": [{
            "Name": "title",
            "Path": "/schemarootname/title",
            "IsMultiValue": false,
            "Semantics": [{
                "Prefix": "tri",
                "Entity": "schemarootname",
                "Property": "title"
            }],
            "Fields": []
        }, {
            "Name": "items",
            "Path": "/schemarootname/items",
            "IsMultiValue": true,
            "Semantics": [{
                "Prefix": "tri",
                "Entity": "schemarootname",
                "Property": "items"
            }],
            "Fields": []
        }
    },

However this field is not binding in the view model.

I have tried to debug the issue by just having a single field in the modelclass without any luck. I am using DXA Java 1.6 with SDL Tridion 2013 SP1. To simplify the question I have removed other fields from model and semantics. Can anyone suggest what I am missing.

Answer 1

I think the problem here is that the implicit semantic mapping "de-pluralizes" the name of a list-type property. So, a property called "items" implicitly maps to a CM field called "item".

However, as visible in the schemas.json fragment you provided, your CM field is called "items" too. This means you will need an explicity semantic mapping: add a @SemanticProperty("items") annotation on your View Model property.

Answer 2

After generating trace level log, I was able to identify that issue is because of the creating view model with default mapping. In Trace log it was showing error message:

05:56:16.770 [http-nio-8080-exec-2] TRACE c.s.w.c.i.mapping.SemanticMapperImpl - No match found for field: private java.util.List modelclass.items; registry semantics: [FieldSemantics(vocabulary=SemanticVocabulary(id=http://www.sdl.com/web/schemas/core, prefix=null, vocab=null), entityName=modelclass, propertyName=item)]  

Thanks Rick. When I was posting my findings in the answer, I have seen you have already posted the answer. I have added the semantic property to the field and issue got resolved. Few learning here:

• Useful to generate trace level log in case you face strange model mapping issue. In debug log you might miss the detailed log about field mapping issue.

• Property with List type(in my case items) is by default mapped to a
  singular name(item). So if there is any change in this relation add
  semantic property to the model.