breeze.partial-entities.js

define(function () {
        var mapper = {
            mapDtosToEntities: mapDtosToEntities
        };

        return mapper;
        
        function mapDtosToEntities(manager, dtos, entityName) {
            // Map an array of DTO's for a type of entity 
            // to an array of Breeze entities that are managed by 
            // the entity manager and are observables
            var entityArray = dtos.map(dtoToEntityMapper);
            return entityArray;

            function dtoToEntityMapper(dto) {
                var metadataStore = manager.metadataStore,
                    entityType = metadataStore.getEntityType(entityName),
                    id = dto.id,
                    key = new breeze.EntityKey(entityType, id),
                    entity = manager.getEntityByKey(key);
                if (!entity) {
                    // We don't have it, so create it as a partial
                    entity = entityType.createEntity({id: id, isPartial: true});
                    manager.attachEntity(entity);
                }
                mapToEntity(entity, dto);
                entity.entityAspect.setUnchanged();
                return entity;
            }

            function mapToEntity(entity, dto) {
                // entity is an object with observables, dto is json
                for (var prop in dto) {
                    if (dto.hasOwnProperty(prop)) {
                        entity[prop](dto[prop]);
                    }
                }
                return entity;
            }
        }

    });