@crosspath/yambus

Yambus

This package generates functions for accessing application routes (e.g. create_account_path) and performing requests to the application (e.g. create_account).

See gem Railbus for integration with Rails framework.

Installation

$ yarn add @crosspath/yambus

Recommended step: add adapter for generating requests. Do one of these commands:

$ yarn add @crosspath/yambus-axios
$ yarn add @crosspath/yambus-fetch

Package yambus-axios uses axios library that supports latest browser versions and IE9+. Package yambus-fetch uses native function fetch that isn't available in IE but you may use it with Edge, Chrome, Firefox, Safari, Opera.

Also you may write adapter for any other library or function. Package yambus-axios contains very short code that you may use as base for writing your adapter.

Usage

Assume you have an object for defining application routes:

{
  // Route names will be used for names of generated functions as
  // `${route_name}` for requests and `${route_name}_path` for getting path.
  route_name: {
    // HTTP verbs: 'get', 'post', 'put', 'patch', 'delete', 'head'.
    // Lower case!
    verb: 'get',

    // ':url' is a placeholder for a value, and any ':value' too.
    path: '/string/representation/of/your/:url',

    // Array of strings and objects. Each object has form `{a: 'name'}`,
    // it contains name of placeholder for a value.
    parts: ['/string/representation/of/your/', {a: 'url'}],

    // Array of strings. Each string is name of placeholder for a value.
    required: ['url'],

    // The same `route_name`
    name: 'route_name'
  }, ...
}

This object should be generated, not written by hand.

Now you may use your routes for generating functions with Yambus:

// Example file name: routes.js

import yambus from '@crosspath/yambus'

// Import adapter for doing requests via Axios.
// Axios is not required but used for demonstration purpose.
// You may use `yambus-fetch` package or any other library for HTTP requests.
import { request } from '@crosspath/yambus-axios'

const routes = { /* your application routes */ }

const route_functions = yambus.generate_route_functions(
  routes,
  (route, args) => request(route, yambus.build_request_options(route, args))
)

export default route_functions

Import this file and call its functions:

import Routes from 'routes'

// Get path with positional arguments:
console.log(Routes.route_name_path('test-value'))
// Or with object:
console.log(Routes.route_name_path({url: 'test-value'}))
// Result:
// => /string/representation/of/your/test-value

How does it work? When you use positional arguments (first case above), values are passed to elements of parts in this route, one-by-one in the same order. And when you use {object} (second case), values passed to the named elements of parts using placeholders like {a: 'url'}.

Also you may call requests to the application:

// Send request with positional arguments:
Routes.route_name('test-value').then(resp => console.log(resp.data))
// Or with object:
Routes.route_name({url: 'test-value'}).then(resp => console.log(resp.data))

These functions return Promise. See adapters' README for more info about value of resp variable.

Functions' arguments

Here String or Number, ... represents values used in paths, e.g. :id, :category_id (zero, one or more params); that's positional arguments for generating paths (first case).

And ...path_params means object with values for paths, e.g. {id: 123, category_id: 56} (zero, one or more params); that's passing object with values for generating paths (second case).

data here means request body (payload), it can be {object}, FormData and so on, its allowed types depend on library or function for doing requests.

// Request actions with `get` & `delete` verbs.
({format: String, ...path_params, ...url_options})
// Or:
(String or Number, ..., {format: String, ...url_options})

// Request actions with `post`, `put`, and `patch` verbs.
({format: String, ...path_params, ...url_options}, data)
// Or:
(String or Number, ..., {format: String, ...url_options}, data)

// Get path for any action (does not include query string starting with '?').
({format: String, ...path_params})
// Or:
(String or Number, ..., {format: String})

format is optional. If passed it will be appended to the path as /your/url.json for {format: 'json'}.

All arguments are optional. But if you need to pass data and leave path params empty, then you should pass explicit first argument {}. For example,

const fd = new FormData()
fd.append('attachment', input.files[0]) // Assume `input` is `<input/>` node.
Routes.attach_file({}, fd) // Instead of `Routes.attach_file(fd)`.

Available exported functions

build_request_options(route, args) -> {path, url_options, data}

Purpose: parse arguments and apply values to path's placeholders.

Arguments:

• route, object {verb, path, parts, required, name}, it's your app route
• args, array of String | Number | Object, contains passed arguments to path & request functions

Returns:

• path, string, URL
• url_options, Object, contains passed arguments to path & request functions (except request body)
• data, null or Object, request body

---

generate_route_functions(routes, request_function) -> {...}

Purpose: create functions for getting application paths and performing requests.

Arguments:

• routes, Object, collection of your app routes
• request_function, function (route, args) => Promise, function for doing requests. Params route & args are the same as in build_request_options.

Returns:

• key-value Object, where key is function's name and value is function

---

has_blob(obj, level = 0) -> boolean

Purpose: check whether this object contains Blob (attached File). If it has Blob then this object should be send with FormData.

Arguments:

• obj, Object, data for request body
• level, Number, how deep in the data we are now. Recursion stops on level >= 1000.

Returns:

• true if obj is object and contains Blob
• false, otherwise

---

build_form_data(obj) -> FormData

Purpose: wrapper for creating FormData object. obj should not be FormData.

Arguments:

• obj, Object, data for request body

Returns:

• FormData object

Contributing

Bug reports and pull requests are welcome on GitHub at github.com/crosspath/yambus.

Please do not change version number in pull requests.

License

This package is available as open source under the terms of the MIT License.