get-uri

What is get-uri?

The get-uri npm package is designed to retrieve the contents of a URI string using different protocols. It supports protocols like HTTP, HTTPS, Data, File, and more. The package provides a simple API to fetch URIs in a protocol-agnostic way, which can be particularly useful when working with a variety of resource identifiers.

What are get-uri's main functionalities?

HTTP/HTTPS URI retrieval

This feature allows you to retrieve resources over HTTP or HTTPS. The code sample demonstrates how to fetch a resource from 'http://example.com' and pipe the response stream to the standard output.

const getUri = require('get-uri');

getUri('http://example.com', function (err, rs) {
  if (err) throw err;
  rs.pipe(process.stdout);
});

Data URI retrieval

This feature enables you to decode Data URIs and access the data as a stream. The code sample shows how to decode a base64-encoded 'Hello, World!' message from a Data URI and pipe it to the standard output.

const getUri = require('get-uri');

getUri('data:text/plain;base64,SGVsbG8sIFdvcmxkIQ==', function (err, rs) {
  if (err) throw err;
  rs.pipe(process.stdout);
});

File URI retrieval

This feature allows you to read local files using the file URI scheme. The code sample demonstrates how to create a file URI from a local file path and then use get-uri to read the file and pipe its contents to the standard output.

const getUri = require('get-uri');
const path = require('path');

const filePath = path.resolve('path/to/your/local/file.txt');
const fileUri = 'file://' + filePath;

getUri(fileUri, function (err, rs) {
  if (err) throw err;
  rs.pipe(process.stdout);
});

Other packages similar to get-uri

request

The 'request' package is a popular HTTP client for making HTTP requests. It is more focused on HTTP/HTTPS and does not support other URI schemes like get-uri does. However, it offers a rich set of features for interacting with HTTP resources.

axios

Axios is a promise-based HTTP client for the browser and Node.js. Similar to 'request', it is primarily used for HTTP/HTTPS requests and does not natively handle other URI schemes. Axios provides a clean, promise-based API and is widely used for web service integration.

node-fetch

Node-fetch is a light-weight module that brings the Fetch API to Node.js. It is designed to provide a simple interface for fetching resources over HTTP/HTTPS, similar to what is available in modern browsers. Unlike get-uri, it does not support non-HTTP URI schemes.

README

get-uri

Returns a stream.Readable from a URI string

This high-level module accepts a URI string and returns a Readable stream instance. There is built-in support for a variety of "protocols", and it's easily extensible with more:

Protocol	Description	Example
data	Data URIs	data:text/plain;base64,SGVsbG8sIFdvcmxkIQ%3D%3D
file	File URIs	file:///c:/windows/example.ini
ftp	FTP URIs	ftp://ftp.kernel.org/pub/site/README
http	HTTP URIs	http://www.example.com/path/to/name
https	HTTPS URIs	https://www.example.com/path/to/name

Example

To simply get a stream.Readable instance from a file: URI, try something like:

import { getUri } from 'get-uri';

// `file:` maps to a `fs.ReadStream` instance…
const stream = await getUri('file:///Users/nrajlich/wat.json');
stream.pipe(process.stdout);

Missing Endpoints

When you pass in a URI in which the resource referenced does not exist on the destination server, then a NotFoundError will be thrown. The code of the error instance is set to "ENOTFOUND", so you can check for that value to detect when a bad filename is requested:

try {
  await getUri('http://example.com/resource.json');
} catch (err) {
  if (err.code === 'ENOTFOUND') {
    // bad file path requested
  } else {
    // something else bad happened...
    throw err;
  }
}

Cacheability

When calling getUri() with the same URI multiple times, the get-uri module supports sending an indicator that the remote resource has not been modified since the last time it has been retrieved from that node process.

To do this, define a cache property on the "options object" argument with the value set to the stream.Readable instance that was previously returned. If the remote resource has not been changed since the last call for that same URI, then a NotModifiedError instance will be thrown with its code property set to "ENOTMODIFIED".

When the "ENOTMODIFIED" error occurs, then you can safely re-use the results from the previous getUri() call for that same URI:

// First time fetches for real
const stream = await getUri('http://example.com/resource.json');

try {
  // … some time later, if you need to get this same URI again, pass in the
  // previous `stream.Readable` instance as `cache` option to potentially
  // have an "ENOTMODIFIED" error thrown:
  await getUri('http://example.com/resource.json', { cache: stream });
} catch (err) {
  if (err.code === 'ENOTMODIFIED') {
    // source file has not been modified since last time it was requested,
    // so you are expected to re-use results from a previous call to `getUri()`
  } else {
    // something else bad happened...
    throw err;
  }
}

API

getUri(uri: string | URL, options?: Object]): Promise

A uri is required. An optional options object may be passed in:

• cache - A stream.Readable instance from a previous call to getUri() with the same URI. If this option is passed in, and the destination endpoint has not been modified, then an ENOTMODIFIED error is thrown

Any other options passed in to the options object will be passed through to the low-level connection creation functions (http.get(), ftp.connect(), etc).

Returns a stream.Readable instance to read the resource at the given uri.