<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
<xs:element name="Segments">
  <xs:complexType>
    <xs:sequence>
      <xs:element maxOccurs="unbounded" name="Segment">
        <xs:complexType>
          <xs:attribute name="Title" type="xs:string" use="required" />
          <xs:attribute name="Value" type="xs:unsignedByte" use="required" />
        </xs:complexType>
      </xs:element>
    </xs:sequence>
  </xs:complexType>
</xs:element>
</xs:schema>

The XML content below exposes a data series containing three segments A, B and C with respective values of 10, 15 and 25.

The following source code is a C# class that returns our sample data series and exposes it through an ASP.net Web service

using System;
using System.Collections.Generic;
using System.Xml;
using System.Xml.Serialization;
using System.Web.Services;

namespace ChartingForSharePoint
{
   public struct Segment
   {

     [XmlAttribute]
     public string Title;

     [XmlAttribute]
     public int Value;

     public Segment(string title, int value)
     {
       Title = title;
       Value = value;
     }
   }

   [WebService(Namespace = http://api.acme.com/services)]
   [WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
   public class SampleSeriesService : WebService
   {

     [WebMethod]
     [return: XmlRoot("Segments")]
     public List<Segment> GetSampleSeries(string inParam)
     {
        List<Segment> segments = new List<Segment>();
        segments.Add(new Segment("A", 10));
        segments.Add(new Segment("B", 15));
        segments.Add(new Segment("C", 25));
        return segments;
     }
   }
}

Registering the service

The C# class has to be compiled into a signed assembly. This assembly has to be registered into the GAC of your server, or copied into the bin directory of your Web application (in this case, make sure CAS policies are correctly configured for your assembly).

The ASMX file has to be copied at root level or into a subdirectory of folder C:\Program Files\Common file\Microsoft Shared\web server extensions\12\ISAPI on your Web front-end server.

The Web service is ready to run, but you must register it via an STSADM command in order to make SharePoint exposing its WSDL schema correctly. If you omit this step, no WSDL schema will be exposed when trying to access the service description via the special WSDL query string token.

Use the registerwebservice STSADM operation with syntax below to register the Web service to SharePoint. This custom STSADM command is automatically deployed when setting-up Charting for SharePoint on your system.

You can use the syntax below from a command prompt to obtain the list of parameters supported by the operation

C:\...\12\BIN>stsadm.exe -help registerwebservice

The table below gives details about each parameter

Parameter	Details	Comments
url	Absolute URL of the Web service	If the ASMX file is stored in folder 12\ISAPI, the service URL will be http://<host>/<sitecollection-url>/_vti_bin/<service-file>.asmx Note that you only need to register the service for one site collection on one Web application to make it globally available to Charting Web Parts
username	Login of the account used to access the service	This parameter is optional. You only need to specify credentials if the Web application uses basic authentication. Login can be composed of a username only, or it can contain a domain and a username separated by a backslash character (e.g. DOMAIN1\userA)
password	Password of the account used to access the service	Warning: the password will be sent in clear when calling the service

Below is a screenshot of how to register our sample service on the localhost Web application. If you receive the message Operation completed successfully, the Web service definition file is available to SharePoint.

You can ensure that the WSDL definition file is available by accessing the service URL from a Web browser and then click the Service description link, or by appending ?WSDL at the end of the service URL (see sample below)

Authentication methods

Charting Web Parts are relying on Web browser credentials cache to access Web services. Thus, we advise you to connect to Web services located on the same Web application as Web Part pages. This way, Charting Web Parts are compliant with native SharePoint authentication methods:

• Basic authentication
• Windows integrated authentication
• Forms authentication
• Anonymous authentication

Using a Web service as a data source

Possible errors and resolutions

The table below is a non-exhaustive list of possible errors that can occurs when using mapping editor.

Error message	Resolution
Unable to cast object of type 'System.Web.Services.Description.HttpAddressBinding' to type 'System.Web.Services.Description.SoapAddressBinding'	Try to register the Web service on the same Web application as the Web Part page. Refers to § “Registering the service” for more details about how to register a Web service.
There is an error in XML document (3, 2)	WSDL description address is invalid. Make sure that you’ve appended the WSDL query string token to the URL of service description file. If yes, try to access the URL you’ve specified from a Web browser to ensure that it returns the WSDL schema of the service.
Exception: Protocol error	URL of the service description file is not well formed. Open a Web browser and make sure you can access the service with URL you’ve specified.
404 not found	The URL you’ve specified as the service description file address does not exist. Open a Web browser and make sure you can access the service with URL you’ve specified.