schema-mapper-tranformer

Transform an Item or Metadata by applying Changes to it.

Installation

npm install --save schema-mapper-transformer

Usage

Transforming an item

Items can be transformed by applying changes to it. The following table shows how the item object is modified by each type of change

• column.rename - Renames the key in the item object, keeping it's value
• column.create - Adds the key to the item object with a null value
• column.remove - Removes the key from the item object
• column.typechange - Nulls the value
• schema.remove - Nulls the item object
• project.remove - Nulls the item object

var transformer = require('schema-mapper-transformer');
var item = {
  user_id: 1,
  name: 'Koen'
};
var changes = [
  {
    change: 'column.rename',
    projectId: '1',
    schemaId: '1',
    columnId: '1',
    name: 'id',
    oldName: 'user_id'
  },
  {
    change: 'column.create',
    projectId: '1',
    schemaId: '1',
    columnId: '3',
    column: {
      name: 'email',
      type: 'string'
    }
  },
  {
    change: 'column.remove',
    projectId: '1',
    schemaId: '1',
    columnId: '2',
    oldColumn: {
      name: 'name',
      type: 'string'
    }
  }
];
var result = transformer.transformItem(item, changes);
console.log(result);

{
  id: 1,
  email: null
}

Transforming metadata

Metadata can be transformed by applying changes to it. The following table shows how the metadata object is modified by each type of change

• project.rename - Updates the projectName property
• project.tag - Updates the projectVersion property
• schema.remame - Updates the schemaName property

var metadata = {
  projectName: 'demo',
  projectVersion: 1,
  schemaName: 'users'
};
var changes = [
  {
    change: 'project.rename',
    projectId: '1',
    name: 'demoproject',
    oldName: 'demo'
  },
  {
    change: 'project.tag',
    projectId: '1',
    version: 2,
    oldVersion: 1
  },
  {
    change: 'schema.rename',
    projectId: '1',
    schemaId: '1',
    oldName: 'user',
    name: 'users'
  }
];

var result = transformer.transformMetadata(metadata, changes);
console.log(result);

{
  projectName: 'demoproject',
  projectVersion: 2,
  schemaName: 'users'
}

API docs

API Docs

Licence

MIT