/// <summary>
/// Generate error message which highlights services with circular dependencies.
/// </summary>
/// <remarks>
/// <para>You can check the value of <see cref="HasCircularDependency"/> to
/// determine whether circular dependencies hvae been detected before using
/// this method.</para>
/// </remarks>
/// <returns>
/// A string containing an error message when circular service dependencies
/// have been detected; otherwise, a value of <c>null</c>.
/// </returns>
/// <seealso cref="HasCircularDependency"/>
public string GenerateCircularDependencyErrorMessage()
{
var sb = new StringBuilder();
sb.AppendLine(CircularDependencyNodes.Count() > 2 ? "Has circular dependencies" : "Has circular dependency");
sb.AppendLine("Select this log entry to see circular dependencies:");
var remainingCircularNodes = new HashSet <ServiceDependencyGraph.Node>(CircularDependencyNodes);
while (remainingCircularNodes.Count != 0)
{
var circularNode = remainingCircularNodes.First();
remainingCircularNodes.Remove(circularNode);
sb.AppendLine();
sb.AppendLine(circularNode.Installer.TargetService.ServiceType.FullName);
// Produce list of other services that form circular dependency.
var circular = new HashSet <ServiceDependencyGraph.Node>();
AddCircularDependencies(circularNode, circular);
circular.Remove(circularNode);
// Present immediate dependencies first.
foreach (var n in circularNode.Targets)
{
sb.AppendLine(" ➜ " + n.Installer.TargetService.ServiceType.FullName);
circular.Remove(n);
remainingCircularNodes.Remove(n);
}
// Then present subsequent dependencies.
foreach (var n in circular)
{
sb.AppendLine(" → " + n.Installer.TargetService.ServiceType.FullName);
remainingCircularNodes.Remove(n);
}
}
return(sb.ToString());
}
/// <summary>
/// Generate error message which highlights services with circular dependencies.
/// </summary>
/// <remarks>
/// <para>You can check the value of <see cref="HasCircularDependency"/> to
/// determine whether circular dependencies hvae been detected before using
/// this method.</para>
/// </remarks>
/// <param name="contextInstaller">Circular dependencies are reported if related
/// to the specified context service installer.</param>
/// <returns>
/// A string containing an error message when circular service dependencies
/// have been detected; otherwise, a value of <c>null</c>.
/// </returns>
/// <exception cref="System.ArgumentNullException">
/// If <paramref name="contextInstaller"/> is a value of <c>null</c>.
/// </exception>
/// <seealso cref="HasCircularDependency"/>
public string GenerateCircularDependencyErrorMessage(IServiceInstaller contextInstaller)
{
if (contextInstaller == null)
{
throw new ArgumentNullException("contextInstaller");
}
var circularNode = CircularDependencyNodes.FirstOrDefault(n => n.Installer == contextInstaller);
if (circularNode != null)
{
// Produce list of other services that form circular dependency.
var circular = new HashSet <ServiceDependencyGraph.Node>();
AddCircularDependencies(circularNode, circular);
circular.Remove(circularNode);
var sb = new StringBuilder();
sb.AppendLine(circular.Count > 1 ? "Has Circular Dependencies:" : "Has Circular Dependency:");
sb.AppendLine();
// Present immediate dependencies first.
foreach (var n in circularNode.Targets)
{
sb.AppendLine(" ➜ " + n.Installer.TargetService.ServiceType.FullName);
circular.Remove(n);
}
// Then present subsequent dependencies.
foreach (var n in circular)
{
sb.AppendLine(" → " + n.Installer.TargetService.ServiceType.FullName);
}
return(sb.ToString());
}
else
{
return(null);
}
}
