For Programmers: About NodeXL Graph Data Providers

Oct 7, 2009 at 12:27 AM
Edited Mar 12, 2014 at 1:14 AM
The NodeXL Excel Template can directly import graph data from a variety of sources, including other Excel workbooks, UCINET files, Pajek files, and GraphML files. It also has a plug-in architecture that can be used to import graph data in other unsupported formats. If you are a .NET programmer, you can create a custom graph data provider DLL that can be integrated into the NodeXL Excel Template by simply copying it into a designated plug-ins folder. Custom graph data providers appear in the Excel Template's Import menu, just as if they were built into the Template.

You do not need to build NodeXL to create a graph data provider DLL. You do not need the NodeXL source code at all.

To get started with creating a graph data provider DLL for the NodeXL Excel template, do the following:
  1. Download a version of the NodeXL Class Libraries from the Downloads tab. (For maximum compatibility with various versions of NodeXL, download NodeXL Class Libraries version You'll need the NodeXLApi.chm help file in the download as well as the ExcelTemplatePlugIns.dll file that defines the IGraphDataProvider2 interface. You can ignore all the other assemblies in the download. Again, you do not need NodeXL's source code.
  2. Open the help file. (Important Note: You may see nothing but empty topics when you attempt to open the NodeXLApi.chm file. To fix this problem, which is due to a security restriction in Internet Explorer, right-click the chm file in Windows Explorer, select Properties, and click the Unblock button on the General tab.)
  3. Read the "IGraphDataProvider2 Interface" topic in the help file.
As mentioned in the help file, the NodeXL Class Libraries download contains a simple graph data provider implementation called SampleGraphDataProvider.