TypeScript HAF App Template

Sample HAF indexer and API server. Indexes Hive from a starting block number for relevant insert_operation_here operations using the HAF app sync algorithm.

How To Use This Template

HAF App Names

Replace every instance of myhaf_app with your actual HAF app name in:

• All SQL files in src/sql folder
• src/constants.ts
• .env.example
• This README file

Replace every instance of myhaf_api with your actual HAF app API schema name in:

• src/sql/create_apis.sql
• src/sql/drop_db.sql
• src/server.ts
• PostgREST start scripts in scripts folder (including docker)
• This README file

Replace every instance of myhaf_owner with your actual HAF app owner role in:

• src/sql/create_apis.sql
• src/sql/builtin_roles.sql
• This README file

Replace every instance of myhaf_user with your actual HAF app API user in:

• src/sql/create_apis.sql
• PostgREST start scripts in scripts folder (including docker)
• This README file

Replace the environment variable prefix HAFAPP in:

• .env.example
• Dockerfile
• config.ts

Table Definitions

Write the PostgreSQL table definitions in src/sql/create_tables.sql file. All registered tables (forking app) must contain the column hive_rowid as shown in the example table. List the registered table names (without schema name) in src/schema.ts, under HAF_TABLES array.

Then define foreign key definitions in the same file under HAF_FKS object, and list those definitions that has to be dropped when uninstalling the HAF app in src/sql/drop_db.sql.

Function Definitions

An example PL/pgSQL function for fetching custom_json operations has been defined in src/sql/create_functions.sql. Adapt the function to your desired set of operation IDs by referring to the operations list linked in the file.

Define all operation processing methods in the same file.

API Definitions

Define PostgREST API definitions in src/sql/create_apis.sql file under the HAF app API schema. For APIs that must be written in TypeScript, define the Express API methods in src/server.ts.

Define Express API request types in src/server_types.ts.

Config Definitions

Define additional configuration required in config.js file. All constants are to be defined in constants.ts.

Operation Validation and Execution

Include the required validation for operations fetched from myhaf_app.enum_op() in src/processor.ts file in validateAndParse() method. Execute the operations by calling the operation processing PL/pgSQL methods in process() within the same file.

State Providers

Import the required state providers in src/schema.ts. The accounts state provider has been included as an example.

Docker

A sample Dockerfile is supplied in this template. Replace all instances of hafapp with your app name, and substitute environment variables with your defined prefix. Additionally, adjust the names in scripts/postgrest_docker_start.sh file accordingly.

Everything Else

• Replace the LICENSE file with your desired license.
• Replace all values in package.json with actual names and URLs.
• Delete this section of the README file and update the HAF app description above.

Required Dependencies

• nodejs and npm (Latest LTS, v18 minimum supported)
• Synced HAF node

Setup

PostgreSQL Roles

psql -f src/sql/builtin_roles.sql haf_block_log

PostgREST Installation

./scripts/postgrest_install.sh

PostgREST API methods

psql -f src/sql/create_apis.sql block_log

Installation

git clone https://github.com/techcoderx/typescript-haf-app-template
cd typescript-haf-app-template
npm i

Compile

npm run compile

Sync

npm start

Start PostgREST server

./scripts/postgrest_start.sh postgres://myhaf_user:<myhaf_user_password>@localhost:5432/block_log <server_port>

Start Express server

npm run server