aarongauthier2019/example-supply-chain

This repo demonstrates one way to use smart functions in Fluree to govern a supply chain process.

Supply Chain

This Github repo demonstrates a coffee supply chain application backed by Fluree. The application follows a purchase order as it goes from the grower to the roaster to the cafe.

The infrastucture for this example is simple:

• Fluree server
• Thin, React layer

This use case demonstrates Fluree smart functions, or in other words how data protects itself.

Features demonstrated: smart functions.

Get Started

1. Start Fluree

Download and unzip this Fluree packet. The packet contains Fluree, version 0.13.0, as well as a prepopulated database with the schema, seed data, smart functions, and purchase orders (you can find these transactions in resources/).

Navigate to the folder where you downloaded the packet, and run ./fluree_start.sh. If you have Java 8+ installed, this should launch Fluree, and a Admin Console will be available for you to explore at http://localhost:8080/index.html. resources/example_queries.js has example queries you can test out directly in the Admin Console.

2. Start the App

git clone https://github.com/fluree/example-supply-chain.git

cd example-supply-chain

npm install

npm start

How Does it Work

Smart functions in Fluree govern what information can be updated and transacted in Fluree. Smart functions can be applied at different locations:

• For an Individual - You can apply smart functions to a given auth record. This means that whenever that auth record does anything, certain rules apply. Those rules won't apply to other users (unless their auth records have the same rules).

• Across the Board - Smart functions can also be applied at the collection or predicate level. This means that any time * anyone * tries to add, update, or delete a subject in a collection or a subject with a given predicate, certain rules apply.

If a certain transaction triggers individual smart functions, due to the auth record that issued it, AND across the board smart functions due to the subjects it is updating, ALL relevant smart functions are applied.

In this example, all auth records have root access. This means, by default, any participant can view or update anything. However, on top of that, we layer smart functions that apply across the board. Just because rules are applied across the board, DOESN'T mean that everyone has the same access. Many of the smart functions in this example use the relationship? function, which returns true if a certain relationship is present, or false otherwise.

Example Smart Functions: purchaseOrder/closed

We'll look at just one predicate as an example - purchaseOrder/closed. The purchaseOrder/closed predicate references an organization. Think of this predicate as the digital equivalent of an organization printing its name at the bottom of a paper form. We want to make sure that the name being printed matches the signature, and that you are only printing your own name. To that effect, the purchaseOrder/closed predicate has three smart functions:

Smart Function	Code	Explanation
orgAuthIsSelf	(relationship? (?o) [\"organization/auth\"] (?auth_id))	The organization in purchaseOrder/closed has to match the ?auth_id signing this transaction.
didAuthReceiveShipment?	(relationship? (?sid) [\"purchaseOrder/shipments\" \"shipment/receivedSignature\" \"organization/auth\"] (?auth_id))	The organization in purchaseOrder/closed has to have received this shipment before it can closed the purchase order.* This is one of the smart functions that enforces a chain of provenance.
authIsCafe?	(relationship? (?auth_id) [\"organization/_auth\" \"organization/type\"] [\"_tag/id\", \"organization/type:cafe\"])	Finally, the only a cafe can close a purchase order.

* A more robust example would include features like cancelled purchase orders, but that is not included in this simplified demo.

As you are trying out the demo yourself, you can click on the "View Smart Funcions" buttons throughout the application to see which smart functions apply to that predicate and collection. For example, when you click, purchaseOrder/closed, you will see both the smart functions that apply to the purchaseOrder/closed predicate AND the purchaseOrder collection.

Example Queries

There are other example queries that you can try out in /resources/example_queries.js.

Visual Studio Code

If you are using Visual Studio Code to view this repo, you can issue the example queries using the extension.

1. Download the Fluree: Beta extension. In the top menu bar, select View > Extensions. Then search Fluree: Beta and click install.
2. Open the Command Palette by going to View > Command Palette, and issue Fluree: Set Config.
3. Highlight any query in resources/example_queries.js, using the Command Palette, issue, Fluree: Query, and the results of the query will appear in a flureeResponse.txt file. Note: every time you issue a query or transaction, this file gets overwritten.

Resources

To see more example projects, visit our developer hub repo.

Check out our entire documentation or jump directly to the section on smart functions.

You can also engage with us via email, [email protected].

Or by Slack.