DiscoveryClientProtocol.Discover(String) Method

Definition

Namespace:

System.Web.Services.Discovery

Assembly:

System.Web.Services.dll

Discovers the supplied URL to determine if it is a discovery document.

public:
 System::Web::Services::Discovery::DiscoveryDocument ^ Discover(System::String ^ url);

public System.Web.Services.Discovery.DiscoveryDocument Discover (string url);

member this.Discover : string -> System.Web.Services.Discovery.DiscoveryDocument

Public Function Discover (url As String) As DiscoveryDocument

Parameters

url

String

The URL where XML Web services discovery begins.

Returns

DiscoveryDocument

A DiscoveryDocument containing the results of XML Web services discovery at the supplied URL.

Exceptions

WebException

Accessing the supplied URL returned an HTTP status code other than OK.

InvalidOperationException

The url parameter is a valid URL, but does not point to a valid discovery document.

Examples

The following code example is a Web Form that populates a DataGrid with the details about the documents in the Documents property together with the references found in each document during XML Web services discovery. The PopulateGrid method fills the DataGrid with the results from a Discover invocation followed by a call to ResolveAll.

 protected void Discover_Click(object Source, EventArgs e)
 {
  // Specify the URL to discover.
  string sourceUrl = DiscoURL.Text;
  // Specify the URL to save discovery results to or read from.
  string outputDirectory = DiscoDir.Text;

      DiscoveryClientProtocol client = new DiscoveryClientProtocol();
  // Use default credentials to access the URL being discovered.
      client.Credentials = CredentialCache.DefaultCredentials;

      try 
      {
        DiscoveryDocument doc;
        
        // Only discover discovery documents, which might contain references to other types of discoverable documents.  
    doc = client.Discover(sourceUrl);
   
        // Resolve all possible references from the supplied URL.
        client.ResolveAll();
      }
      catch ( Exception e2) 
      {
        DiscoveryResultsGrid.Columns.Clear();
        Status.Text = e2.Message;
      }
  // If documents were discovered, display the results in a data grid.
      if (client.Documents.Count > 0)
      PopulateGrid(client);

  // Save the discovery results to disk.
      DiscoveryClientResultCollection results = client.WriteAll(outputDirectory, "results.discomap");
      Status.Text = "The following file holds the links to each of the discovery results: <b>" + 
                                  Path.Combine(outputDirectory,"results.discomap") + "</b>";
}

Public Sub Discover_Click(Source As Object, e as EventArgs )
   ' Specify the URL to discover.
   Dim sourceUrl as String = DiscoURL.Text
   ' Specify the URL to save discovery results to or read from.
   Dim outputDirectory As String = DiscoDir.Text

   Dim client as DiscoveryClientProtocol = new DiscoveryClientProtocol()
   ' Use default credentials to access the URL being discovered.
   client.Credentials = CredentialCache.DefaultCredentials
   Try 
     Dim doc As DiscoveryDocument
     ' Only discover discovery documents, which might contain references to other types of discoverable documents. 
     doc = client.Discover(sourceUrl)

 ' Resolve all possible references from the supplied URL.
     client.ResolveAll()
           
    Catch e2 As Exception
       DiscoveryResultsGrid.Columns.Clear()
       Status.Text = e2.Message
    End Try

    ' If documents were discovered, display the results in a data grid.
    If (client.Documents.Count > 0) Then
         'populate our Grid with the discovery results
     PopulateGrid(client)
    End If

    ' Save the discovery results to disk.	    
    Dim results As DiscoveryClientResultCollection 
    results = client.WriteAll(outputDirectory, "results.discomap")
    Status.Text = "The following file holds the links to each of the discovery results: <b>" + _ 
                                  Path.Combine(outputDirectory,"results.discomap") + "</b>"
   End Sub

Remarks

The Discover method expects that the supplied URL is a discovery document. If the URL refers to a service description or an XML schema an exception is thrown. To discover an XML schema or a service description invoke the DiscoverAny method.

If the supplied URL points to a valid discovery document, the discovery document at the supplied URL is added to the Documents and References collection. Additionally, references within the discovery document are added to the References collection, but not verified to point to valid discovery documents. To verify the references, point to valid discovery documents to invoke the ResolveAll or ResolveOneLevel methods.