I want to create a custom DataSource which gets the data from a GraphQL Endpoint.
I've looked at JsonDataSource but the problem is that it only has a string property for the json. Data used in reports can get quite large and therefore i need a method of geting the data paged from the backend.
How can i achieve this with the report designer, i haven't found anything on this specific scenario in the docs.
Our Reporting components do not support server-mode data sources. So, it is not possible to load data to reports by using data pages. The main reason why such data sources are not supported, because whole data is required to build the reprot's document.
However, the JSON Data Source is not the only option for your case. As I see from the GraphQL | Code | C# / .NET page the GraphQL support .NET data connectors that will help you to load data from GraphQL to an IList collection. So, you can also use the approach described in the Bind a Report to an Object Data Source help topic to bind your reports to data from GraphQL. This way, you can load data by smaller portions based on your own logic before passing it to the report.
Finally, would you please elaborate more on you scenario. Are you using a Web Report Designer in your application? If so, do you wish to provide your End-Users a capability to connect GraphQL themselves, or do you wish to just provide them with a set of pre-defined data sources?