Requirements AzureData

Phase 0: Refactor

Cosmos DB DocumentDB/SQL API Coverage
Migrate code that can be reused by other SDKs to AzureCore
Support full Cosmos DB DocumentDB/SQL API
TokenProvider updates to support multiple Auth/Resource Token requirements
Add metadata to response object
Implement optimistic concurrency control (OCC) by adding appropriate Headers
- If-None-Match on all GET
- If-Modified-Since on GET (ignored when If-None-Match is specified)
- If-Match on PUT and DELETE
Conflict resolution
- Latest wins (silent)
- Mine wins (silent)
- Manual (callback)
Save tokens to Keychain (AzureCore)
Querying resources
- Support for "raw" SQL queries (validation?)
- Query type and custom syntax language for chaining together conditions
Overrides for partition keys
Add altLink property to Resource and populate from x-ms-alt-content-path
- Note: altLink will only be populated if selfLink is populated as both require the resource to be committed to the remote database to get those values
Create and persist a record of id <-> _rid relationships with an API for getting one with the other
Add createOrReplace API for Documents using the x-ms-documentdb-is-upsert header

Phase 1: Data Persistence

Offline persistence is enabled by default (for all resources)
User has option to disable offline persistence (for all resources)
Data is successfully written remotely before caching locally
Only READING is supported while device is offline, WRITE throws a (useful) error
Add fromCache to response object when returning data from cache (device offline)
Simple API to Purge entire data cache
DELETEing a resource remotely deletes the cached version (only if the delete was successful indicated by a response status code of 204 No Content)
If GET request returns 404 Not Found (deleted remotely), check for existing cashed/local resource and delete
When deleting the cached resource, also delete the persisted record the resources' id <-> _rid relationship
Encryption interface for user to implement custom encrypt and decrypt
Resources are cached on disk as folders/files (opposed to SQLite, etc.) matching the path constructed using resources' (_rid) hierarchy (currently stored in the selfLink property)

Example

A Document in the database account https://databaseaccount.database.com located at the following path (selfLink):

dbs/1KtjAA==/colls/1KtjAImkcgw=/docs/1KtjAImkcgwBAAAAAAAAAA==/

Would be represented in the file system like this:

[databaseaccount.database.com]
└──[dbs]
    └──[1KtjAA==]
        ├──1KtjAA==.json
        └──[colls]
            └──[1KtjAImkcgw=]
                ├──1KtjAImkcgw=.json
                └──[docs]
                    └──[1KtjAImkcgwBAAAAAAAAAA==]
                        ├──1KtjAImkcgwBAAAAAAAAAA==.json
                        └──[attachments]
                            └──...

Phase 2: Offline Write

Add WRITE support when offline
Queue writes when offline
Automatically push any local changes as soon as device comes back online
- Send global notification to let user know data changed