Shared-Utils

A collection of shared utils.

Supported languages are English and German.

Contents

• Installation
• How to work with Date Formats
• How to work with Date parameters
• How to work config Defaults
• Dates
  • relativeDateAccurate
  • relativeDateLoose
  • formatDate
  • getWeekdayOfDate
  • getMonthOfDate
• Strings
  • leftPad
• State Listeners
  • onAppChangesVisibility
• Lifecycle
  • wait
• License

Installation

npm install @jaaahn/shared-utils

Import all utils bundled under one object:

import * as utils from "@jaaahn/shared-utils";

Date formats

Sometimes a utility function takes a dateFormat argument. This is a string like: YYYY-MM-DD. The symbols are later replaced by actual values. These symbols are available:

• YYYY => the date's year
• MM => month
• DD => date
• hh => hours
• mm => minutes
• ss => seconds
• ms => milliseconds

Date parameters

Often a date input is required. This date can be passed as a JS Date, a valid date string JavaScript can interpret or as a number representing the milliseconds counting up from 1th Jan, 1970. These input dates are in the following reference only marked as the date data type.

Config Defaults

Some utilities have opional parameters, like dateFormats or the lang parameter. These have default values that can be overwritten when calling the function (by specifying the parameters) or globally through the defaults object.

Changing defaults

// Import the library
import * as utils from "@jaaahn/shared-utils";

// Change a default
utils.defaults.dateFormat = "DD-MM-YYYY";

Available settings and their values

{
    dateFormat: "DD.MM.YYYY",
    dateTimeFormat: "DD.MM.YYYY, hh:mm",
    lang: "EN",
}

Dates

relativeDateAccurate

Output a relative representation of the difference between now and an input date. Will always try to give a accurate description, even opting to show a full date with timestamp.

relativeDateAccurate(input: date, [lang: string], [dateFormat: string]) : string

input : date
The date that should be formated. Can either be a JS date or a correct date string.

lang? : string ="EN"
The language of the output.

dateFormat? : string ="DD.MM.YYYY"
Format of the output.
See how to provide these formats

relativeDateLoose

Output a relative representation of the difference between now and an input date.

relativeDateLoose(input: date, [lang: string]) : string

input : date
The date that should be formated. Can either be a JS date or a correct date string.

lang? : string ="EN"
The language of the output.

formatDate

Formats a date according to the passed formatting rules.

formatDate(input: date, [dateTimeFormat: string]) : string

input : date
The date that should be formated. Can either be a JS date or a correct date string.

dateTimeFormat? : string ="DD.MM.YYYY, hh:mm"
Format of the output.
See how to provide these formats

getWeekdayOfDate

Takes a JS Date and returns the name of the weekday.

getWeekdayOfDate(input: date, [lang: string]) : string

input : date
The date of which the weekday should be extracted.

lang? : string ="EN"
The language of the output.

getMonthOfDate

Takes a JS Date and returns the name of the month.

getMonthOfDate(input: date, [lang: string]) : string

input : date
The date of which the month should be extracted.

lang? : string ="EN"
The language of the output.

Strings

leftPad

Appends a filler character if necesarry, e.g. 7 with filler "0" => "007" E.g. 7 gets turned into "007", if fillUpTo = 3.

leftPad(input: number, [fillUpTo: number], [filler: string]) : string

input : number
The input number to modify.

fillUpTo? : number =2
The amount of digits to fill up. E.g. 7 gets turned into "007", if fillUpTo = 3.

filler? : string ="0" Character used to fill up input

State Listeners

onAppChangesVisibility

Fires a callback if the app goes into foreground (or background).

onAppChangesVisibility(reactToState : string, callback: function) : function

reactToState : string
Must be "foreground" or "background". If this state is activated, the callback will be fired.

callback : function
Callback that should be fired if app changes visibility to the specified state.

Returns: function
When called, the event listener is removed. Use for example when the page unloads, to avoid two event listeners if the page is reloaded.

Lifecycle

wait

A promise based wait function, that sets a timeout and resolves if the timout fires. Most useful with async/await.

wait(ms : number) : promise

ms : number Time to wait in milliseconds

License

MIT License
Copyright (c) 2021 Jaaahn