LoadDocument now requires a static string collection name

[JoshuaLevett]

I had an index in 4.2 that used a LoadDocument call like this:

Map = participationDocs => from participationDoc in participationDocs
let signup = LoadDocument<IEventInstance>(participationDoc.SignupId, participationDoc.SignupId.Substring(0, participationDoc.SignupId.IndexOf('/')))

I've updated to 5.2.3 and the index now errors stating that the collection name must be a static string.
In order to accommodate this, I've had to create the multi-map index with selectors like the below (I've only included up to loading the "signup" as the rest isn't relevant)

AddMap<SignupParticipation> (participationDocs => from participationDoc in participationDocs
where participationDoc.SignupId.Substring(0, participationDoc.SignupId.IndexOf('/')).ToLower() == "physicalevents"
let signup = LoadDocument<IEventInstance>(participationDoc.SignupId, "physicalevents")

AddMap<SignupParticipation> (participationDocs => from participationDoc in participationDocs
where participationDoc.SignupId.Substring(0, participationDoc.SignupId.IndexOf('/')).ToLower() == "onlineevents"
let signup = LoadDocument<IEventInstance>(participationDoc.SignupId, "onlineevents")

AddMap<SignupParticipation> (participationDocs => from participationDoc in participationDocs
where participationDoc.SignupId.Substring(0, participationDoc.SignupId.IndexOf('/')).ToLower() == "ondemands"
let signup = LoadDocument<IEventInstance>(participationDoc.SignupId, "ondemands")

This means I have had to write out the map 3 times (more will need to be added too)
Is this a feature that was intentionally removed? Or have I missed a new potential implementation?

Help / advice is appreciated as this may be a pain to maintain

[ppekrol]

We added additional validation, your 4.2 index probably was detecting referenced collections incorrectly, hence it was not reacting to changes of these as it should.

The string there must be a const in order for us to detect those referenced collection names.

[JoshuaLevett]

Sorry, this is just for my own understanding.
Are you saying that the 4.2 index might not have correctly updated the index if, for example, the "PhysicalEvent" document was updated?

[ppekrol]

Yes. It might not react to that change properly.