I am unable to understand how the application flow is when I use group docs embedded viewer.
To me it seems like , the documents will always have to me uploaded into groupdocs and accessed later based on the guid.
But I have my documents placed somewhere else (legacy system) and I would expect to view those using the group docs viewer. Is it not achievable without uploading the documents ?
The viewhandler initialization constructor in this code takes the inputdatahandler . But with 2.8.0 version of the groupdocs-viewer jar file, the constructor does not take this parameter.
How do I set the custom input data source handler ?
Sorry to see you have this problem. I suggest you to start with the provided samples (http://groupdocs.com/Community/files/9/java-libraries/groupdocs_viewer_for_java/entry750.aspx), for example with the Spring one. There in the src/main/java/com/groupdocs/HomeController.java on line 46 and below you can find different options of the ViewerHandler instance initialization. You can change the default initialization to this one
viewerHandler = new ViewerHandler(config, new CustomInputDataHandler(config));
The constructor in this implementation of the InputDataHandler is not necessary it is just a sample of the implementation. You can modify it in the way you need it.
Try to start simply with the provided Spring sample and the GroupDocs.Viewer v2.8.0 for Java library with only configuration modification (i.e. basePath) to see how the application works. Then you can modify the InputDataHandler implementation up to your needs.