TemplateProvider

By default, we read .sql files in sql folder as our template sources. But if you want to read templates from other sources like databases, s3 ...etc., TemplateProvider can help you.

How TemplateProvider works

Extension Id is required

This extension needs you set an id for VulcanSQL, use @VulcanExtensionId decorator from @vulcan-sql/core to decorate your class. For example:

@VulcanExtensionId('mock')
export class MockTemplateProvider extends TemplateProvider { }

TemplateProvider only needs you to implement getTemplate function, you should return an AsyncGenerator.

Every entity should have two properties:

• name: The name of this template. VulcanSQL maps this name with templateSource.
• statemnet: The content of this template.

@VulcanExtensionId('mock') // Chose a extension id
export class MockTemplateProvider extends TemplateProvider {
  public async *getTemplates(): AsyncGenerator<Template> {
    yield {
      name: 'template1', // The name of this template
      statement: 'select 1 as a', // The content of this template
    };
    yield {
      name: 'template2',
      statement: 'select 2 as a',
    };
  }
}

To enable your template provider, you'll need to change template.provider to your extension id.

vulcan.yaml

name: "vulcan-demo-extensions"
description: A starter Vulcan project
version: 0.2.0
template:
  provider: mock # Change to you extension id
  folderPath: sqls
  codeLoader: InMemory

Example

info

You can check the demo repository for the full code.

import {  Template,  TemplateProvider,  VulcanExtensionId,} from '@vulcan-sql/core';@VulcanExtensionId('mock')export class MockTemplateProvider extends TemplateProvider {  public async *getTemplates(): AsyncGenerator<Template> {    yield {      name: 'filter-runner-and-builder',      statement: 'select 1 as a',    };    yield {      name: 'tag-runner-and-builder',      statement: 'select 2 as a',    };  }}