sqlsol - A solidity event driven SQLite3 cache for syncing with smart contracts
See here for some standard library goodies
Table of Contents
About
Here you will find code to simplify the process of querying a running blockchain. An example is provided to demonstrate building an application on a event based auto-updating sql table tied to smart contracts. This facilitates building smart contract applications on the Eris Platform
Example
The smart contract application example that is provided allows participants and viewers to verify a history of events attached to a particular object (in this case eggs).
Due to the public nature of the data attached to the egg, one must carefully consider their goals before using it as a source of any degree of security. The primary source of security is the requirement of two party agreement to a transfer through signed transactions by user's own private key.
Install
- have eris-cli installed
Usage
npm install
node examples/EggTracker/server.jsWait for it to finish its start up procedure.
Note: For simplicity, the start up sequence boots a temporary test chain and deploys the contracts. While this makes it easier to start, it means that every time you run this script, a brand new contract with no data will be created. Adapt the example for your purposes.
API
Making data
The server serves an endpoint for creating eggs
GET http://localhost:1212/secret/:desc
(todo: should be a POST)
:desc is a description of the egg.
Enter the url either in curl curl http://localhost:1212/secret/wordsgohere
(in a second terminal), or by putting the url in a browser.
You will see some output (from the server terminal) indicating that things are being updated. This is the egg's data and history being generated (printed out to demonstrate the event emitter). Once completed, a message will be returned telling you the eggid of the newly created egg.
Retrieving data
Three endpoints are provided to demonstrate data retrieval from the cache.
GET http://localhost:1212/eggs/:eggid
returns a JSON object of the egg data, including history
GET http://localhost:1212/pp/:eggid
returns HTML showing egg data (for browsers)
GET http://localhost:1212/ppcmd/:eggid
returns formatted strings for when calling by curl.
In all of the above, :eggid is the id assigned to the egg upon creation, that you wish to retrieve data for.
Contribute
See the eris platform contributing file here.
Resources
examples/EggTracker/server.js - main app file
examples/EggTracker/eggStruct.json - the definition file
examples/EggTracker/contracts/eggtracker.sol - the smart contract we are using