public async Task UpdateNode(PersonFamilyTreeNode oldNode, PersonFamilyTreeNode newNode)
{
var client = await Neo4JConnection.GetClient();
var txClient = (ITransactionalGraphClient)client;
using (var transaction = txClient.BeginTransaction())
{
try
{
var children = await GetChildren(oldNode.Id);
await DeleteNode(client, oldNode);
await AddNewNode(client, newNode);
await ReacreateRelationships(newNode, client, children);
await transaction.CommitAsync();
}
catch (Exception e)
{
await transaction.RollbackAsync();
throw e;
}
}
}
private static async Task ReacreateRelationships(PersonFamilyTreeNode newNode, Neo4jClient.GraphClient client, List <string> children)
{
foreach (var child in children)
{
await CreateParentRelationship(client, newNode.Id, child);
await CreateChildRelationship(client, newNode.Id, child);
}
}
private async static Task DeleteNode(Neo4jClient.GraphClient client, PersonFamilyTreeNode personFamilyTreeNode)
{
await client.Cypher.Match("(a:Person)")
.Where("a.Id = $id")
.WithParam("id", personFamilyTreeNode.Id)
.DetachDelete("a")
.ExecuteWithoutResultsAsync();
}
private async static Task CreateNode(Neo4jClient.GraphClient client, PersonFamilyTreeNode personFamilyTreeNode)
{
await client.Cypher.Create("(n:Person { Id: $id, Name: $name, FatherId: $fatherId, MotherId: $motherId })")
.WithParam("id", personFamilyTreeNode.Id)
.WithParam("name", personFamilyTreeNode.Name)
.WithParam("fatherId", personFamilyTreeNode.FatherId)
.WithParam("motherId", personFamilyTreeNode.MotherId)
.ExecuteWithoutResultsAsync();
}
public async Task Handle(PersonCreatedEvent @event)
{
var personFamilyTreeNode = new PersonFamilyTreeNode()
{
Id = @event.Person.Id,
Name = @event.Person.Name,
FatherId = @event.Person.FatherId,
MotherId = @event.Person.MotherId
};
await PersonFamilyTreeRepository.AddNode(personFamilyTreeNode);
}
private static async Task AddNewNode(Neo4jClient.GraphClient client, PersonFamilyTreeNode personFamilyTreeNode)
{
var idFather = personFamilyTreeNode.FatherId;
var idMother = personFamilyTreeNode.MotherId;
var idChild = personFamilyTreeNode.Id;
await CreateNode(client, personFamilyTreeNode);
await CreateParentRelationship(client, idFather, idChild);
await CreateChildRelationship(client, idFather, idChild);
await CreateParentRelationship(client, idMother, idChild);
await CreateChildRelationship(client, idMother, idChild);
}
public async Task RemoveNode(PersonFamilyTreeNode personFamilyTreeNode)
{
var client = await Neo4JConnection.GetClient();
var txClient = (ITransactionalGraphClient)client;
using (var transaction = txClient.BeginTransaction())
{
try
{
await DeleteNode(client, personFamilyTreeNode);
await transaction.CommitAsync();
}
catch (Exception e)
{
await transaction.RollbackAsync();
throw e;
}
}
}
public async Task Handle(PersonUpdatedEvent @event)
{
if (HasChangedParents(@event))
{
var oldNode = new PersonFamilyTreeNode()
{
Id = @event.OldPersonData.Id,
Name = @event.OldPersonData.Name,
FatherId = @event.OldPersonData.FatherId,
MotherId = @event.OldPersonData.MotherId
};
var newNode = new PersonFamilyTreeNode()
{
Id = @event.NewPersonData.Id,
Name = @event.NewPersonData.Name,
FatherId = @event.NewPersonData.FatherId,
MotherId = @event.NewPersonData.MotherId
};
await PersonFamilyTreeRepository.UpdateNode(oldNode, newNode);
}
}
