transform-api-response.js

A nodejs library to transform API responses into biolink model

install

npm i @biothings-explorer/transform-api-response

usage

fetch(url, options, mapping, baseMapping = null)

• url - The URL of the API endpoint
• options - A fetch options object that is compatible with node-fetch.
• mapping - A mapping object.
• baseMapping - An object that holds the starting point path for the mapping. Default is "root".

mapping object

This object holds the configurations to tranform the API response to the desired object.

1. Keys: String. represents a key name in the tranformed result. Currently dynamic key names are not supported.
2. Values, One of two options:
3. String. hold the path to the desired value in the API response.
4. Object. A mapping operation for array items.

mapping operations

This object represent a predefined complex operation of mapping. It's structure:

[operation(args)]

• operation - The name of the operation
• args - Required argument for the operation

See also: Supported mapping operations

path

A path always start from "root" and represents the pointer to the response object. Supported syntax:

• .string - e.g. "root.key"
• [int] - e.g. "root[0]"
• ['string'] - e.g. "root['key']"

Examples

Suppose API POST https://example.com/echo responsds with the provided JSON body. So this code:

const TransformJsonAPI = require('transform-json-api');

const url = "https://example.com/echo";
const options = {
  method: "POST",
  body: {
    data: {
      test: true,
      items: [
        {index: 1, name: "item 1"},
        {index: 2, name: "item 2"}
      ]
    }
  }
}
const mapping = {
    "item_names": "root[map(root.name)]",
}

const transorm = TransformJsonAPI.fetch(url, options, mapping, "root.data.items")
// transorm ->  ["item 1", "item 2"]

format()

format(input:string|object, [output:string|object])

A simple string template function based on named or indexed arguments base on this string-template package

const greeting = format("Hello {name}, you have {count} unread messages", {
    name: "Robert",
    count: 12
})
// greeting -> "Hello Robert, you have 12 unread messages"

Excepts Objects as well

parameters()

parameters([input:string|object])

returns keys from a string template

const keys = parameters("Hello {name}, you have {count} unread messages");
// keys -> ["name", "count"]

Alternative with multiple arguments and not just with strings

const greeting = "Hello {name}, you have {count} unread messages";
const publishedAt = {"package_{id}": "Published at: {date}"};

const [greetingKeys, publishedAtKeys] = parameters(greeting, publishedAt);

// greetingKeys -> ["name", "count"]
// publishedAtKeys -> ["id", "date"]

License

This package is licensed under the Apache 2.0 license.