1859859 - Construct translation layer between structured message model and front end

Status: NEW

(Thunderbird :: General, enhancement)

Description

[Sean Burke [:leftmostcat]]

The existing nsIMsgMessageService interface forces implementations to mix concerns. The backend is given a string URI and a handle to a document shell into which to load a URI. Implementations are then expected to construct an overloaded URI object to load into the doc shell along with a lot of context data.

In order to replace this, we wish to provide an interface for the backend which takes a message URI as a plain URI object and returns a structured representation of the corresponding message, which the front end is then responsible for rendering appropriately.

In order to provide a smooth transition and avoid significant churn across all protocols, we need to construct a translation layer which implements nsIMsgMessageService and is capable of building the URI needed by the backend for fetching, receiving the structured message in response, and handling the process of loading it into the docshell.

The backend-facing part of the translation layer and its internals will necessary be in flux as the message model is developed as part of the EWS support effort.