XML-RPC

XML-RPC
- Links
  - COM client implementations
- Toolkits
  - vbXmlRpc
  - comxmlrpc

Toolkits

vbXmlRpc

This is written in VB and has no external dependencies, except that the vbXmlRpc depends on the vbXml library.

The API is 'message based' - you construct the request message and then handle the response message. Here's an example of contructing the request:

Dim linsRequest As New XMLRPCRequest
linsRequest.HostName = "www.oreillynet.com"
linsRequest.HostPort = 80
linsRequest.HostURI = "/meerkat/xml-rpc/server.php"
linsRequest.MethodName = "meerkat.getChannelsByCategory"
linsRequest.Params.AddInteger (List1.ItemData(List1.ListIndex))

Here's the basic send-request / handle-response code:

Dim linsResponse As XMLRPCResponse
Set linsResponse = linsRequest.Submit

If linsResponse.Status <> XMLRPC_PARAMSRETURNED Then
  BugOut "Unexpected response from XML-RPC request " & linsResponse.Status
ElseIf linsResponse.Params.Count <> 1 Then
  BugOut "Unexpected response from XML-RPC request " & linsResponse.Params.Count & _
    " return parameters, expecting 1"
ElseIf linsResponse.Params(1).ValueType <> XMLRPC_ARRAY Then
  BugOut "Unexpected response from XML-RPC request " _
    & linsUtility.GetXMLRPCType(linsResponse.Params(1).ValueType) _
    & " returned, expecting an array"
End If

And here's an example of extracting data from the response :

Dim linsValue As XMLRPCValue
Dim linsMember As XMLRPCMember

For Each linsValue In linsResponse.Params(1).ArrayValue

    If linsValue.ValueType <> XMLRPC_STRUCT Then
        BugOut "Unexpected response from XML-RPC request " _
          & linsUtility.GetXMLRPCType(linsResponse.Params(1).ValueType) _
          & " returned, expecting a struct"
    End If
        
    For Each linsMember In linsValue.StructValue
        If linsMember.Name = "id" Then
            llngChanId = linsMember.Value.IntegerValue
        ElseIf linsMember.Name = "title" Then
            lstrChanTitle = linsMember.Value.StringValue
        End If
    Next linsMember
        
    List2.AddItem lstrChanTitle
    List2.ItemData(List2.ListCount - 1) = llngChanId
        
Next linsValue

Both the vbxml.dll and vbxmlrpc.dll are well documented with .chm files. Both projects built clean in VB6, and the code itself is well written. Performance seems to be OK - the meerkat example (portions of which are shown above) was very responsive over a dialup connection.

comxmlrpc

Here's the only documentation, from the home page:

Examples

Calls "someClass.sum" in server localhost, port 80, path /RPC2 with '3' and '5' as arguments


dim xmlrpcserver as comxmlrpc.rpcClient
dim params() as Variant 
dim x as Integer
set xmlrpcserver = new comxmlrpc.rpcClient
redim params(1) 
params(0) = 3 
params(1) = 5 
xmlrpcserver.uri = "http://localhost:80/RPC2" 
x = xmlrpcserver.execute("someClass.sum",params)

Calls "someClass.structRecv" with a struct as parameter


dim xmlrpcserver as comxmlrpc.rpcClient 
dim params() as Variant 
dim x as Integer 
set xmlrpcserver = new comxmlrpc.rpcClient 
dim dictionary As Object 
Set dictionary = CreateObject("Scripting.Dictionary") 
dictionary.Add "name", "ignacio" 
dictionary.Add "age", "17" 
redim params(0) 
set params(0) = dictionary 
xmlrpcserver.uri = "http://localhost:80/RPC2" 
x = xmlrpcserver("someClass.structRecv",params) ' using .execute default method

This has numerous bugs, to the point of unusability. On the other hand it's only a couple hundred lines of code (uses MSXML4 and the base64 encoding library by Alvaro Redondo), so fixing it shouldn't be a huge chore.

-- DaleBrayden - 25 Jun 2003

b r a y d e n . o r g / Software

XML-RPC

Links

COM client implementations

Toolkits

vbXmlRpc

comxmlrpc