README

query

This package is intended for consumption via the @profiscience/knockout-contrib metapackage

Persistent, stateless read/write querystring abstraction for KnockoutJS.

Basic Usage

import { Query, Router } from '@profiscience/knockout-contrib'

const query = Query.create({ sort: 'alpha' })

query.sort() // alpha

// If you are using this package with the router from knockout-contrib as well,
// you probably want to configure it to preserve the querystring between navigation
// since we're managing it externally.
Router.setConfig({
  preserveQueryStringOnNavigation: true,
})

API

Query.create([config = {}, name])

Create a new query instance passing a configuration object and optionally a name to group the query with. This allows you to create multiple query objects with the same params, and they will not interfere with each other. It also allows you to link queries if they are given the same group name.

The configuration object contains key/value pairs of querystring param names and their config, respectively. A querystring param config may be an object that contains any combination of three props, default, initial, and coerce, or a value which will be used as the default and initial value. The coerce function allows you to transform a value before it is fully set.

const query = Query.create({
  // query param named foo
  foo: {
    default: 'foo',
    initial: 'bar',
    coerce: (v) => (v === 'baz' ? 'qux' : v),
  },

  bar: 'bar',
})

In this case, the foo param will be set to "bar" initially — if not already in the querystring — but call to query.clear() will then set it to "foo". The coerce function disallows setting the param to "baz", and attempting to will cause it to be set to "qux" instead.

NOTE: Params that are equal to their default will not be displayed in the querystring. Less === More.

Query.reload()

Reload query instances if external changes occur (e.g. querystring modified via pushState/replaceState). Usually you don't need to call this directly, as long as you include the query router middleware, if you are using the router.

Query.fromQS([group])

Returns JS object containing current query from URL — for group if any.

Query.setParser({ parse, stringify })

By default, this lib is dumb, and it does not use valid querystrings. Instead, it uses JSON.stringify and encodeURIComponent, and vice versa. This function allows you to define a custom parser.

e.g.

import Query from 'ko-querystring'
import rison from 'rison' // https://github.com/Nanonid/rison

Query.setParser({
  parse: rison.decode_object,
  stringify: rison.encode_object,
})

query[param]

Query params are created via super-cool ES6 proxies, so you don't need to explicitly define all the query params you will use. Simply access them, and they are there.

Params will be initialized from the querystring if available, and their default value or undefined if not.

query[param].clear()

Resets param to its default or undefined.

query[param].isDefault

Observable value that is true if the param is its default value, otherwise false.

query.set(default || { default, initial, coerce })

Change the default values for a query.

query.clear()

Reset all the query params to their defined defaults, or undefined.

query.toJS()

Returns unwrapped query object.

query.toString()

Returns stringified query.

query.asObservable()

Return observable query object. i.e. ko.observable({ foo: 'foo' }) instead of { foo: ko.observable('foo') }

query.dispose()

Disposes the query object and cleans the querystring. Don't forget to clean up after 'yo self.

MOAR!

Check the test file or the source. This lib is small enough to understand inside and out.

@profiscience/knockout-contrib-query

Usage no npm install needed!