/// <exception cref="ArgumentNullException">The specified arguments are null</exception>
/// <exception cref="ArgumentException">A feature with the specified name already exists</exception>
/// <exception cref="ResourceNotFoundException{Feature}">The referenced parent feature does not exist</exception>
public Feature CreateFeature(FeatureArgs args)
{
if (args == null)
{
throw new ArgumentNullException(nameof(args));
}
if (Db.Features.Any(f => f.Name == args.Name))
{
throw new ArgumentException($"A feature with name '{args.Name}' already exists");
}
var feature = new Feature {
Name = args.Name
};
if (args.Parent != null)
{
feature.Parent = GetFeature(args.Parent.Value);
if (feature.Parent == null)
{
throw new ResourceNotFoundException <Feature>(args.Parent);
}
}
Db.Features.Add(feature);
Db.SaveChanges();
return(feature);
}
public IActionResult Create([FromBody] FeatureArgs args)
{
if (!UserPermissions.IsAllowedToAdminister(User.Identity))
{
return(Forbid());
}
if (!ModelState.IsValid)
{
return(BadRequest(ModelState));
}
try
{
var feature = _manager.CreateFeature(args);
return(Created($"{Request.Scheme}://{Request.Host}/api/Features/{feature.Id}", feature.Id));
}
catch (ResourceNotFoundException <Feature> e)
{
return(StatusCode(422, e.Message)); // invalid parent feature ID
}
catch (ArgumentException e)
{
return(StatusCode(409, e.Message)); // feature name already in use
}
}
public IActionResult Update(int featureId, [FromBody] FeatureArgs args)
{
if (!UserPermissions.IsAllowedToAdminister(User.Identity))
{
return(Forbid());
}
if (!ModelState.IsValid)
{
return(BadRequest(ModelState));
}
try
{
_manager.UpdateFeature(featureId, args);
return(NoContent());
}
catch (ArgumentException e)
{
return(StatusCode(409, e.Message)); // new feature name already in use
}
catch (ResourceNotFoundException <Feature> e) when((int?)e.Keys.FirstOrDefault() == featureId)
{
return(NotFound(e.Message)); // feature to be updated does not exist
}
catch (ResourceNotFoundException <Feature> e)
{
return(StatusCode(422, e.Message)); // referenced parent feature does not exist
}
catch (InvalidOperationException e)
{
return(StatusCode(409, e.Message)); // invalid parent modification
}
}
/// <summary>
/// Updates a feature. If the reference to the parent is modified, this moves the whole subtree of features.
/// </summary>
/// <exception cref="ArgumentNullException">The specified arguments are null</exception>
/// <exception cref="ArgumentException">The new feature name is already in use</exception>
/// <exception cref="ResourceNotFoundException{Feature}">There is no feature with the specified ID</exception>
/// <exception cref="InvalidOperationException">Parent modification causes a cycle (destroys tree structure)</exception>
public void UpdateFeature(int featureId, FeatureArgs args)
{
if (args == null)
{
throw new ArgumentNullException(nameof(args));
}
if (Db.Features.Any(f => f.Name == args.Name && f.Id != featureId))
{
throw new ArgumentException($"A feature with name '{args.Name}' already exists");
}
var feature = GetFeature(featureId, loadParent: true, loadChildren: true, loadGroups: true);
if (feature == null)
{
throw new ResourceNotFoundException <Feature>(featureId);
}
var newParent = args.Parent.HasValue ? GetFeature(args.Parent.Value, loadChildren: true) : null;
if (newParent == null && args.Parent.HasValue)
{
throw new ResourceNotFoundException <Feature>(args.Parent.Value);
}
// ensure that the new parent is not a descendant of or equal to the feature to be updated
// (this would create a cycle destroying the tree structure)
if (IsDescendantOrEqual(newParent, feature))
{
if (args.Parent != null)
{
throw new InvalidOperationException($"Changing the parent of '{featureId}' to '{args.Parent.Value}' would destroy the tree structure because '{args.Parent.Value}' is a descendant of or the same as '{featureId}'");
}
}
// 1) update name
feature.Name = args.Name;
// 2) detach from old parent
feature.Parent?.Children.Remove(feature);
// 3) attach to new parent
newParent?.Children.Add(feature);
feature.Parent = newParent;
Db.SaveChanges();
}
