SubQuery - Starter Package

The Starter Package is an example that you can use as a starting point for developing your SubQuery project. A subquery package defines which data The Subquery will index from the substrate network, and how it will store it.

##Preparation

Install the SubQuery CLI

Install Subquery CLI globally on your terminal by using Yarn or NPM:

$npm install -g @subql-cli
$yarn global add @subql-cli

Run help to see available commands and usage provide by CLI

$suqbl help

Initialize the starter package

Inside the folder in which you want to create the subquery project, and run this command:

$subql  init --starter

Then you should see a directory subql-starter has been created inside your folder, you can use this as the start point of your project. And the files should be identical as following:

- subql-starter
  L package.json
  L project.yaml
  L README.md
  L schema.graphql
  L tsconfig.json
  L src
    L index.ts
    L mappings
      L Extrinsic.ts

Last, under the suql-starter directory, run follow command to install all the dependency.

$npm install

Configure your project

The Manifest

Inside the project.yaml, defines the substrate extrinsic your subquery indexes, which events \ calls from these extrinsic to pay attention to, and how to map event data to entities that our hosted node will stores and allows to query.

The GraphQL Schema

Next, you need to define the GraphQL schemas inside of schema.graphql file. To know how to write in "GraphQL schema language", we recommend to check out on Schemas and Types.

Mapping function

The mappings transform the substrate data your mappings are sourcing into entities defined in your schema. Mappings are written in a subset of TypeScript called AssemblyScript which can be compiled to WASM (WebAssembly).

We also provided an example of a mapping function in src/mappings/Extrinsic.ts. For each handler that is defined in project.yaml under mapping.handlers, create an exported function of the same name.
Under the src/index.ts，you need to export the functions of handlers has defined in above.

Code generation

Next, run codegen command under your project root directory.

$subql codegen

This will create a new directory src/types which contains all generate entities in AssemblyScript.
Generate entity class for each types you have defined previously in schema.graphql. These classes provide type-safe entity loading, read and write access to entity fields.

Deploy a subquery project

Pack and upload

In order to deploy your subquery project to our hosted service, it is mandatory to pack your configuration before upload. Run pack comand from npm from root directory of your project will automatically generate a your-project-name.tgz file.

$npm pack

Last, all you need to do is upload this file to our host. All good to go.

jiqiang90 / subql-starter