I'm trying to use the REST services (ListData.svc) to retrieve items from a list in a very simple test with Office365. I can't seem to get the connection to work without adding my credentials to the DataSource, which to me is a huge no-no. If I add my credentials, it works fine.
The error is the standard "Unable to display this Web Part. To troubleshoot the problem, open this Web page in a Microsoft SharePoint Foundation-compatible HTML editor such as Microsoft SharePoint Designer. If the problem persists, contact your Web server administrator.", which of course tells me nothing of use.
I admit that I haven't tried this in a local VM, but Office365 is my proving ground in this case.
I found this article on Microsoft's site, but it doesn't help me because I don't have any control over the authentication mechanisms: SharePoint Designer 2010 data sources that consume ListData.svc fail to generate a web part on sites that use NTLM authentication
Has anyone successfully used a DVWP with REST as the DataSource on Office365 without passing credentials in the clear?
I wanted to add a little more info. The reason I want to understand this better is due to a comment I received on one of my blog posts. The post is about how to add the WebURL parameter to the DataSource for a DVWP in SharePoint 2010, and it gets a lot of reads. Since Microsoft removed the "Connect to another library" option in 2010, it's seemed to me that the only recourse is to add the WebURL parameter manually.
So the goal here is to read from a list in a different site than the DVWP, but in the same Site Collection. Since the user is authenticated, this isn't an anonymous situation.
The comment says: "It doesn’t exist anymore, because it is now done through REST. You create a REST connection to any list or library in any site, site collection, web application, or farm. I’ve successfully exposed data in DVWPs from a completely separate farm and version of SharePoint. I took data from my SharePoint Foundation 2010 farm and exposed it in a web part page within my SharePoint Server 2010 farm by making a connection using REST, which is the preferred method now for connecting to other SharePoint content. SOAP can be used, too, but it can’t go across farms, although it can cross site collections. I have a full matrix of all the data source scenarios for each authentication type that will be published in our SharePoint Designer 2010 Unleashed book, which I think will be helpful to many."