RelationService.md

RelationService

Applies to Umbraco 6.1.1 and newer

The RelationService acts as a "gateway" to Umbraco data for operations which are related to Relations.

Browse the API documentation for RelationService.

• Namespace: Umbraco.Core.Services
• Assembly: Umbraco.Core.dll

All samples in this document will require references to the following dll:

• Umbraco.Core.dll

All samples in this document will require the following usings:

using Umbraco.Core;
using Umbraco.Core.Models;
using Umbraco.Core.Services;

Getting the service

The RelationService is available through the ApplicationContext, or if you are using a SurfaceController or the UmbracoUserControl then the RelationService is available through a local Services property.

Services.RelationService

Getting the service through the ApplicationContext:

ApplicationContext.Current.Services.RelationService

Methods

.GetById(int id)

Gets a Relation object by its Id

.GetRelationTypeById(int id)

Gets a RelationType object by its Id

.GetRelationTypeByAlias(string alias)

Gets a RelationType object by its Alias

.GetAllRelations(params int[] ids)

Gets an enumerable list of Relation objects. If the optional array of integer ids is passed in then only the Relation objects with matching Id's will be returned.

.GetAllRelationsByRelationType(RelationType relationType)

Gets an enumerable list of Relation objects which have the specified RelationType.

.GetAllRelationsByRelationType(int relationTypeId)

Gets an enumerable list of Relation objects which have the specified RelationType Id.

.GetAllRelationTypes(params int[] ids)

Gets an enumerable list of RelationType objects. If the optional array of integer ids is passed in then only the RelationType objects with a matching Id will be returned.

.GetByParentId(int id)

Gets an enumerable list of Relation objects that have the specified ParentId.

public IENumerable<IPublishedContent> GetFavorites(int memberId)
{
    var rs = ApplicationContext.Current.Services.RelationService;
    var relType = rs.GetRelationTypeByAlias("memberFavorites");
    var favorites = new List<IPublishedContent>();
 
 
    if (memberId > 0)
    {
        var relations = rs.GetByParentId(memberId).Where(r => r.RelationType.Alias == "memberFavorites");
 
	foreach (var relation in relations)
	{
		favorites.Add(UmbracoContext.Current.ContentCache.GetById(relation.ChildId));
	}
    }
 
    return favorites;
}

.GetByChildId(int id)

Gets an enumerable list of Relation objects that have the specified ChildId.

.GetByParentOrChildId(int id)

Gets an enumerable list of Relation objects that have the specified ParentId or ChildId.

.GetByRelationTypeName(string relationTypeName)

Gets an enumerable list of Relation objects that have the specified RelationType Name.

.GetByRelationTypeAlias(string relationTypeAlias)

Gets an enumerable list of Relation objects that have the specified RelationType Alias.

.GetByRelationTypeId(int relationTypeId)

Gets an enumerable list of Relation objects that have the specified RelationType Id.

.GetChildEntityFromRelation(IRelation relation, bool loadBaseType = false)

Gets the Child object from a Relation passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.GetParentEntityFromRelation(IRelation relation, bool loadBaseType = false)

Gets the Parent object from a Relation passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.GetEntitiesFromRelation(IRelation relation, bool loadBaseType = false)

Gets the Parent and Child objects from a Relation passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.GetChildEntitiesFromRelations(IEnumerable relations, bool loadBaseType = false)

Gets the Child objects from a list of Relations passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.GetParentEntitiesFromRelations(IEnumerable relations, bool loadBaseType = false)

Gets the Parent objects from a list of Relations passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.GetEntitiesFromRelations(IEnumerable relations, bool loadBaseType = false)

Gets the Parent and Child objects from a list of Relations passed into the method. If the loadBaseType parameter is true the complete object graph will be loaded.

.Relate(IUmbracoEntity parent, IUmbracoEntity child, IRelationType relationType)

Relates two objects that implement the IUmbracoEntity interface using the RelationType matching the specified RelationType and returns the resulting Relation object.

.Relate(IUmbracoEntity parent, IUmbracoEntity child, string relationTypeAlias)

Relates two objects that implement the IUmbracoEntity interface using the RelationType matching the specified relationTypeAlias and returns the resulting Relation object.

.HasRelations(IRelationType relationType)

Returns true if there are any Relation objects with the specified RelationType, otherwise returns false.

.IsRelated(int id)

Returns true if any relations exist for the specified Id, otherwise returns false.

.Save(IRelation relation)

Saves a single Relation object.

public void SetFavorite(int memberId, int contentId) {
	var rs = ApplicationContext.Current.Services.RelationService;
	var areRelated = rs.AreRelated(memberId, contentId, "memberFavorites");
 
	if (!areRelated)
	{
		//create relation
		var relType = rs.GetRelationTypeByAlias("memberFavorites");
		var r = new Relation(memberId, contentId, relType);
		rs.Save(r);
	}
}

.Save(IRelationType relationType)

Saves a single IRelationType object.

.Delete(IRelation relation)

Permanently deletes a Relation object.

.Delete(IRelationType relationType)

Permanently deletes a RelationType object.

.DeleteRelationsOfType(IRelationType relationType)

Permanently deletes all relations that match the specified RelationType.