I was asked recently about downloading files from the ServiceAPI using the Content-Range header to support chunked downloads. I was sure that this was supported but it was not working. After some hours of digging I found a problem that caused normal document downloads to ont recognize Content-Range, oddly enough the service to return multiple documents as a zip was working.

Multiple files as a zip

The standard download URL may be used to return documents for multiple records as a zip by using comma separated URI’s, for example:

https://mydev.dev/ServiceAPI/Record/9000000001,9000000002/File/document

If any of the records do not have a document attached they will be ignored.

Custom download addin

If you need to use chunked downloads another solution may be to install the sample plugin in the samples. When added to the ServiceAPI this will add a service called ‘PartialDownload’ that support the Content-Range header. Some code that can be used as a starting point to test this can be found in the getDocumentInChunks sample in the ServiceAPI console app sample.