Transparently interpret id-values or domain instances for DbRef properties in a query or update as DbRefs [DATAMONGO-855]

Thomas Darimont opened DATAMONGO-855 and commented

We should allow using domain object values or values whose types are compatible to the id property of a document as the value for a DbRef property or collection element in updates.

We should also investigate whether it is possible to use the same semantics in queries.

		Sample sample1 = new Sample("1", "A");
		Sample sample2 = new Sample("2", "B");
		template.save(sample1);
		template.save(sample2);

		DocumentWithDBRefCollection doc = new DocumentWithDBRefCollection();
		doc.id = "1";
		doc.dbRefAnnotatedList = Arrays.asList( //
				sample1, //
				sample2 //
				);
		template.save(doc);

 		// use domain object value directly -> transparently interpret as DbRef
		Update update = new Update().pull("dbRefAnnotatedList", sample2);

		// Use id property value -> transparently interpret as DbRef
		Update update = new Update().pull("dbRefAnnotatedList", sample2.id);
	}

	class DocumentWithDBRefCollection {

		@Id public String id;

		@org.springframework.data.mongodb.core.mapping.DBRef//
		public List<Sample> dbRefAnnotatedList;
	}

	class Sample{

	    @Id String id;
  		String field;

		public Sample() {}

		public Sample(String id, String field) {
			this.id = id;
			this.field = field;
		}
  	}

Issue Links:

• DATAMONGO-404 Removing a DBRef using pull does not work