CascadeDataLayer is a kind of multi-tool for building, updating and maintaining client-side data structures consisting of models, collections and associations that represent the back-end and business domain. Cascade is a framework designed to optimize data flow between the user interface and the server with caching and persistence mechanisms. Acting as a back-end for the front-end with a well-defined API with models and relationships, Cascade enables developers to write the user interface in a consistent and meaningful manner.

By providing a robust data layer, Cascade shields the front end from any changes or updates made to the backend. CascadeDataLayer and your ICascadeOrigin implementation handle all the asynchronous complexity and manage back-end inconsistencies so that the models can kept simple and synchronous.

Usage

Cascade also requires an implementation of an abstract origin (server) interface. This means almost any server can be supported, including custom enterprise APIs. Inconsistencies and naming issues can be resolved in custom code to maintain a clean and consistent API for app developers.

The architecture of Cascade is inspired by the concept of cache layers in CPUs. The initial first layer is usually memory based - fastest but limited in size and not persistent. The second is typically file-based - slower, but persistent. Cache layers are abstract, providing developers with the flexibility to implement their preferred caching storage.

As a quick introduction, here are some examples of using the main methods provided by Cascade :

1. var product = await cascade.Create<Product>(new Product() { colour = "Red" });
2. var product = await cascade.Get<Product>(25, populate: new string[] { nameof(Product.Manufacturer) });
3. var redThings = await cascade.Query<Product>("red_products",new JsonObject { ["colour"] = "red" });
4. var updated = await cascade.Update(product, new JsonObject { ["colour"] = "red" });
5. await cascade.Destroy(product);
6. var promoted = await cascade.Execute("PROMOTE",new JsonObject { ["product_id"] = 25 })
7. await cascade.Populate(product,new string[] { nameof(Product.Manufacturer),nameof(Product.Category) })

Application Requirements :

1. Using the SuperModel base class and its attributes for all application models
2. Implementing an origin class for your server(s) API
3. Constructing an instance of CascadeDataLayer with the desired cache layer(s) and origin
4. Using the CascadeDataLayer for application server interactions
5. As for any application that needs to create records offline, you should probably use GUID ids

Features

1. "freshness" option to determine whether to get data from either a cache or the server
2. "fallback freshness" option to silently fallback to a cached data when unable to reach the server
3. "hold" option to mark retrieved records for downloading and preservation offline even when caches are cleared