com.fulcrologic.fulcro.offline.tempid-strategy — com.fulcrologic/fulcro 3.5.6

Temporary ID strategy. Used by offline support to enable disconnected applications to define how Fulcro tempids behave when disconnected. The support allows a client decide to implement ID support in whatever way makes sense to the feature set of the application in offline modes.

• Negotiate a pre-allocated pool of IDs with the server when online.
• Use client-generated UUIDs
• Use the UUIDs within the tempids as the real IDs on the server
• etc.

This ns also includes two pre-written strategies:

TempIDisRealIDStrategy:: This strategy immediately rewrites the tempids in app state to the UUID within the tempid. This allows the client to assign the real ID of the entity immediately, and the server must then either honor that assignment or remap it on success. The server will receive the tempid. This is a very easy way to ensure idempotent save as well, since the server can easily detect when that an incoming tempid has already been saved under that UUID in the database.

NOOPStrategy:: Does nothing. The IDs remain temporary in app state and in the txn sent to the server. Rewrites happen on success.

TempidStrategy clj/s protocol

-resolve-tempids clj/s

(-resolve-tempids this txn)

This function will be given the user-submitted txn. It should return a map for any tempid remappings that are desired immediately, where the keys of the returned map are tempids that appear in the the txn, and whose values are the remapping of those values. If this function returns nothing, then the tempids will remain in app state until the real server remapping is done.

-rewrite-txn clj/s

(-rewrite-txn this txn resolved-tempids)

This operation is called in order to rewrite the outgoing transaction that will eventually be seen by the server. It could simply return txn, it could rewrite the tempids in the txn, or it could add something to tell the server about how it resolved the tempids on the client by augmenting the parameters of the mutations in the transaction.

It will be given the original txn, the resolved-tempids (see resolve-tempids), and must return a txn.

NOTE: This function does not have to remap the tempids in txn. For example, say you are using the uuids within Fulcro tempids as the real IDs. The server can be written to do that, so there would be no need to do any transformation of the txn on the client.