http-fetch-json

httpFetch

Individual fetch API wrapper for the browser (experimental, reactionary)

overview

The thing, is pretty fast as it doesnt try to connect worlds, but rather lives in it's own native environment (the browser). So it will catch up with you faster than you may think.

HTTP request and response routine is super boring but standard procedure for all kinds of stuff.

For the UI and interactions, the browser's api is used, so it's almost the same thing you do at the server side.

While some folks having trouble with so called "native" apis, the best of us are using wrappers (self-made or libs - doesnt matter).

This thing, is kind of a wrapper, but packed with extra options and routes which may or may not happen with you during the HTTP request/response exchange.

It's more advanced that any other tool (which try to keep pace with the NODE's world) as it uses (currently) experimental features of the browser (like fetch, streams, encryption). It may be more aggressive at your environment - only modern syntax, only modern apis (the approach may be same). As far as this time point vanishes in the past, the previous statement becomes falsy.

So, the attempt of escaping the doom is futile: face it one-to-one with the Spider Mastermind.

[](http://www.nathanandersonart.com/) [](https://www.jsdelivr.com/package/npm/http-fetch-json)

Tests

• Fail: check everything
• Cancellation: cancel anything
• Encryption: encrypt everything (FF only)
• Retry: restart anything
• Download: download anything
• Upload: upload anything
• Streams: stream something
• Mix: mix everything

Try

inject into HTML:

# from CDN (stable):
<script src="https://cdn.jsdelivr.net/npm/http-fetch-json@2/httpFetch.js"></script>
# from GIT (lastest)
<script src="http://raw.githack.com/determin1st/httpFetch/master/httpFetch.js"></script>

get the code:

# with GIT (lastest)
git clone https://github.com/determin1st/httpFetch
# with NPM (stable)
npm i http-fetch-json

Syntax

httpFetch(options[, callback(ok, res)])

httpFetch(url[, data[, callback(ok, res)]])

httpFetch(url[, callback(ok, res)])

Parameters

• options - object with:

  basic

  name	type	default	description
  url	string		reference to the local or remote web resource (auto-prefixed with baseUrl if doesn't contain sheme)
  data	any		content to be sent as the request body

  ---

  native fetch

  name	type	default	description
  method	string		HTTP request method (detected automatically)
  mode	string	cors	fetch mode
  credentials	string	same-origin	to automatically send cookies
  cache	string	default	the cache mode to use for the request
  redirect	string	follow	the redirect mode to use. manual is screwed by spec author
  referrer	string		referrer url
  referrerPolicy	string		the referrer policy to use
  integrity	string		the subresource integrity value of the request
  keepalive	boolean	false	allows the request to outlive the page

  ---

  advanced

  name	type	default	description
  status200	boolean	true	to consider only HTTP STATUS 200 OK
  notNull	boolean	false	to consider only nonempty HTTP response body and not JSON NULL
  fullHouse	boolean	false	to include everything, request and response, data and headers
  promiseReject	boolean	false	promise will reject with Error
  timeout	integer	20	request will abort in the given delay in seconds
  redirectCount	integer	5	manual redirects limit (functional only with http status 300)
  aborter	aborter		to cancel request with given controller
  headers	object	{..}	request headers
  parseResponse	string	data	data is to parse all the content to proper content type, stream for FetchStream, otherwise, raw response

  ---

• callback - optional result handler function

  • ok - boolean flag, indicates the successful result
  • res - response result, either success or FetchError

Returns

Promise (no callback) or AbortController (callback)

Result

Optimistic style (the default)

async/await

var res = await httpFetch('/resource');
if (res instanceof Error)
{
  // FetchError
}
else if (!res)
{
  // JSON falsy values
}
else
{
  // success
}

promise

httpFetch('/resource')
  .then(function(res) {
    if (res instanceof Error)
    {
      // FetchError
    }
    else if (!res)
    {
      // JSON falsy values
    }
    else
    {
      // success
    }
  });

callback

httpFetch('/resource', function(ok, res) {
  if (ok && res)
  {
    // success
  }
  else if (!res)
  {
    // JSON falsy values
  }
  else
  {
    // FetchError
  }
});

Optimistic, when notNull

custom instance

var oFetch = httpFetch.create({
  notNull: true
});

async/await

var res = await oFetch('/resource');
if (res instanceof Error)
{
  // FetchError
}
else
{
  // success
}

promise

oFetch('/resource')
  .then(function(res) {
    if (res instanceof Error)
    {
      // FetchError
    }
    else
    {
      // success
    }
  });

callback

oFetch('resource', function(ok, res) {
  if (ok)
  {
    // success
  }
  else
  {
    // FetchError
  }
});

Pessimistic style, when promiseReject

custom instance

var pFetch = httpFetch.create({
  promiseReject: true
});

async/await

try
{
  var res = await pFetch('/resource');
  if (res)
  {
    // success
  }
  else
  {
    // JSON falsy values
  }
}
catch (err)
{
  // FetchError
}

promise

oFetch('/resource')
  .then(function(res) {
    if (res)
    {
      // success
    }
    else
    {
      // JSON falsy values
    }
  })
  .catch(function(err)
  {
    // FetchError
  });

Pessimistic, when promiseReject and notNull

custom instance

var pFetch = httpFetch.create({
  notNull: true,
  promiseReject: true
});

async/await

try
{
  var res = await pFetch('/resource');// success
}
catch (err)
{
  // FetchError
}

promise

oFetch('/resource')
  .then(function(res) {
    // success
  })
  .catch(function(err)
  {
    // FetchError
  });

Result types

• JSON
  • application/json
• String
  • text/*
• ArrayBuffer
  • application/octet-stream
  • ...
• Blob
  • image/*
  • audio/*
  • video/*
• FormData
  • multipart/form-data
• null
  • application/json when JSON NULL
  • application/octet-stream when not byteLength
  • image/*, audio/*, video/* when not size
  • when HTTP response body is empty
• FetchStream
  • when parseResponse is stream
• FetchError
  • when fetch() fails
  • when unsuccessful HTTP status code
  • when not HTTP STATUS 200 OK and status200
  • when JSON NULL and notNull
  • when HTTP response body is empty and notNull
  • ...

FetchError

error categories

if (res instanceof Error)
{
  switch (res.id)
  {
    case 0:
      ///
      // connection problems:
      // - connection timed out
      // - wrong CORS headers
      // - unsuccessful HTTP STATUSes (not in 200-299 range)
      // - readable stream failed
      // - etc
      ///
      console.log(res.message);   // error details
      console.log(res.response);  // request + response data, full house
      break;
    case 1:
      ///
      // something's wrong with the response data:
      // - empty response
      // - incorrect content type
      // - etc
      ///
      break;
    case 2:
      ///
      // security compromised
      ///
      break;
    case 3:
      ///
      // incorrect API usage
      // - wrong syntax used
      // - something's wrong with the request data
      // - internal bug
      ///
      break;
    case 4:
      ///
      // aborted programmatically:
      // - canceled parsing, before the request was made
      // - canceled fetching, before the response arrived
      // - canceled parsing, after the response arrived
      // - stream canceled
      ///
      break;
    case 5:
      ///
      // unclassified
      ///
      break;
  }
}

Advanced

httpFetch.create

httpFetch.create(config)

Parameters

• config - object with options

Description

Creates a new instance of of httpFetch

Examples

var a = httpFetch.create();
var b = a.create();

if ((a instanceof httpFetch) &&
    (b instanceof httpFetch))
{
  // true!
}

httpFetch.cancel

httpFetch.cancel()

Description

Cancels all running fetches of the instance

httpFetch.form

httpFetch.form(url, data[, callback(ok, res)])

httpFetch.form(options[, callback(ok, res)])

Description

httpFetch operates with JSON content by default. This shortcut method allows to send a POST request with body conforming to one of the form enctypes:

• application/x-www-form-urlencoded: query string
• multipart/form-data: FormData with attachments
• text/plain: plaintext The proper content type will be detected automatically.

Parameters

Same as httpFetch

Examples

// CLIENT (JS)
// let's send a plain content without files,
// there is no need in FormData format, so
// it will be automaticly detected as
// x-www-form-urlencoded:
res = httpFetch.form(url, {
  param1: 1,
  param2: 2,
  param3: 3
});

# SERVER (PHP)
# get parameters and calculate their sum:
$sum = $_POST['param1'] + $_POST['param2'] + $_POST['param3'];
# respond with JSON
echo json_encode($sum);
# and quit
exit;

// CLIENT (JS)
// wait for the response and display it:
console.log(await res);// 6

// CLIENT (JS)
// let's send another request with file attached,
// the body will be sent as
// multipart/form-data:
res = await httpFetch.form(url, {
  param1: 1,
  param2: 2,
  param3: 3,
  fileInput: document.querySelector('input[type="file"]')
});
// SERVER's $_FILES will be populated with uploaded file,
// but the response/result will be the same:
console.log(res);// 6

KISS API

Use POST method (Keep It Simple Stupid)

// instead of GET method, you may POST:
res = await httpFetch(url, {});       // EMPTY OBJECT
res = await httpFetch(url, undefined);// EMPTY BODY
res = await httpFetch(url, null);     // JSON NULL
// it may easily expand to
// into list filters:
res = await httpFetch(url, {
  categories: ['one', 'two'],
  flag: true
});
// or item extras:
res = await httpFetch(url, {
  fullDescription: true,
  ownerInfo: true
});
// OTHERWISE,
// parametrized GET will swamp into:
res = await httpFetch(url+'?flags=123&names=one,two&isPulluted=true');

// DO NOT use multiple/mixed notations:
res = await httpFetch(url+'?more=params', params);
res = await httpFetch(url+'/more/params', params);
// DO unified:
res = await httpFetch(url, Object.assign(params, {more: "params"}));

// by default,
// any HTTP status, except 200 is a FetchError:
if (res instanceof Error) {
  console.log(res.status);
}
else {
  console.log(res.status);// 200
}

Links

https://javascript.info/fetch-api

https://tom.preston-werner.com/2010/08/23/readme-driven-development.html

https://code.tutsplus.com/tutorials/why-youre-a-bad-php-programmer--net-18384

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