Transformer

The transformer class is a swiss army knife for manipulating values. especially in combination with the pipe, processing chains can be built up.

Import

import { Transformer } from "@schukai/monster/source/data/transformer.mjs";

Source

View source code

Package

@schukai/monster

Since

1.5.0

Transformer

The `Transformer` class is used to transform data. The transformation is defined as a string.

The following transformations are available:

Command	Parameter	Alias	Description
call	function:param1:param2:...		Calling a callback function. The function can be defined in three places: either globally, in the context addCallback or in the passed object
concat	path or static:path or static:...		This function concatenates the values of the passed paths. If no value in the path is found, the path is used as a static value.
contains			Checks if an array or string contains a value (since 3.17)
currency	maximumFractionDigits:roundingIncrement	money	Convert a currency and amount to a local string (since 3.17)
date			Convert a date string to a localized date string (since 3.16)
datetime			Convert a date string to a localized date-time string (since 3.17)
day			Returns the day of a date (since 3.16)
debug			The passed value is output (console) and returned
default	value:type	??	If the value is undefined the first argument is returned, otherwise the value. The third optional parameter specifies the desired type. If no type is specified, string is used. Valid types are bool, string, int, float, undefined and object. An object default value must be specified as a base64 encoded json string. (since 1.12)
element-by-id		plain	All HTML tags are removed (*)
empty			Return empty String ""
equals	value		Compare the comparison value with the specified value and return true if they match.
first-key	default		Can be applied to objects and returns the value of the first key. All keys of the object are fetched and sorted. (since 1.23)
from-base64		atob	Converts the value from base64
fromjson			Type conversion from a JSON string (since 1.12)
has-entries		hasentries	Checks whether an array or an object has elements. (since 3.17)
hours		hour	Returns the hours of a date (since 3.16)
if	statement1:statement2	?	Is the ternary operator, the first parameter is the valid statement, the second is the false part. To use the current value in the queue, you can set the value keyword. On the other hand, if you want to have the static string "value", you have to put one backslash \\ in front of it and write value. the follow values are true: 'on', true, 'true'. If you want to have a space, you also have to write \\ in front of the space.
index	key:default	property, key	Fetches a value from an object, an array, a map or a set
is-array		isarray	Checks if the value is a array (since 3.17)
is-float		isfloat	Checks if the value is a float (since 3.17)
is-null		isnull	Checks if the value is null (since 3.17)
is-number		isnumber	Checks if the value is a number (since 3.17)
is-object		isobject	Checks if the value is a object (since 3.17)
is-set		isset	Checks if the value is undefined and not null (since 3.17)
is-undefined		isundefined	Checks if the value is undefined (since 3.17)
last-key	default		Can be applied to objects and returns the value of the last key. All keys of the object are fetched and sorted. (since 1.23)
length		count	Length of the string or entries of an array or object
map	key:value:key:value....		Map a value with an existing mapping (since 3.16)
minutes		minute	Returns the minutes of a date (since 3.16)
month			Returns the month of a date (since 3.16)
nop			Do nothing
not			Converts a bolian value into the opposite one (since 3.17)
nth-key	index:default		Can be applied to objects and returns the value of the nth key. All keys of the object are fetched and sorted. (since 1.23)
nth-last-key	index:default		Can be applied to objects and returns the value of the nth key from behind. All keys of the object are fetched and sorted. (since 1.23)
path-exists	path		Check if the specified path is available in the value (since 1.24)
path	path		The access to an object is done via a Pathfinder object
plaintext		plain	All HTML tags are removed ➊
prefix	text		Adds a prefix
rawurlencode			URL coding
seconds		second	Returns the seconds of a date (since 3.16)
static		none	The Arguments value is used and passed to the value. Special characters \and : can be quotet by a preceding \.
substring	start:length		Returns a substring
suffix	text		Adds a suffix
time			Convert a date string to a localized time string (since 3.16)
timestamp			Convert a date string to a time stamp (since 3.16)
to-base64		base64, btob	Converts the value to base64
tointeger			Type conversion to an integer value
tojson			Type conversion to a JSON string (since 1.8)
tolower		strtolower, tolowercase	The input value is converted to lowercase letters
tostring			Type conversion to a string.
toupper		strtoupper, touppercase	The input value is converted to uppercase letters
translation	key:default	i18n	Translations can be applied. The translations must be stored in the DOM. (*) To use the current value as key the first parameter must be set to undefined.
trim			Remove spaces at the beginning and end
ucfirst			First character large
ucwords			Any word beginning large
undefined			Return undefined
uniqid			Creates a string with a unique value ➋
weekday			Returns the day of the week of a date (since 3.16)
year			Convert a date string to a year (since 3.16)

➊ for this functionality the extension jsdom must be loaded in the nodejs context.



if (typeof window !== "object") {
    const {window} = new JSDOM('', {
        url: 'http://example.com/',
        pretendToBeVisual: true
    });
    
    [
        'self',
        'document',
        'Node',
        'Element',
        'HTMLElement',
        'DocumentFragment',
        'DOMParser',
        'XMLSerializer',
        'NodeFilter',
        'InputEvent',
        'CustomEvent',
    ].forEach(key => (global[key] = window[key]));
}

➋ for this command the crypt library is necessary in the nodejs context.


    import * as Crypto from "@peculiar/webcrypto";

    global['crypto'] = new Crypto.Crypto();

With the method `setCallback(name, callback, context)` you can define your own transformation functions. The context parameter is optional and can be used to define the context in which the callback function is called. If no context is specified, the global context is used. In the pipe the name of the callback function is used by prefixing it with a `call:`.


import {Transformer} from '@schukai/monster/source/data/transformer.mjs';

const transformer = new Transformer("call:myCallback");
transformer.setCallback("myCallback", function (value) {
    return value + " world";
});
console.log(transformer.run("hello")); // hello world

Simple

// This is a simple example of how the Transformer class can be used. In this case, 
// the `tolower` function is used to convert a string to lowercase. There are a 
// variety of transformers available for different purposes.

import {Transformer} from '@schukai/monster/source/data/transformer.mjs';

const transformer1 = new Transformer("tolower")

console.log(transformer1.run("HELLO"))
// ↦ hello

console.log(transformer1.run("WORLD"))
// ↦ world


// In the next example, the `length` function is used to return the length of a string.

const transformer2 = new Transformer("length")


console.log(transformer2.run("HELLO"))
// ↦ 5

console.log(transformer2.run("WORLD"))
// ↦ 5

// In the next example, the `substring` function is used to return a substring of a string.
// The `substring` function takes two arguments: the start index and the end index.

const transformer3 = new Transformer("substring:1,3")

console.log(transformer3.run("HELLO"))
// ↦ ELL

console.log(transformer3.run("WORLD"))
// ↦ ORL

Exported

Transformer

Derived from

Base

Options

The Options listed in this section are defined directly within the class. This class is derived from several parent classes. Therefore, it inherits Options from these parent classes. If you cannot find a specific Options in this list, we recommend consulting the documentation of the Base.

Option

Type

Default

Description

-/-

Properties

The Properties listed in this section are defined directly within the class. This class is derived from several parent classes. Therefore, it inherits Properties from these parent classes. If you cannot find a specific Properties in this list, we recommend consulting the documentation of the Base.

Methods

The methods listed in this section are defined directly within the class. This class is derived from several parent classes. Therefore, it inherits methods from these parent classes. If you cannot find a specific method in this list, we recommend consulting the documentation of the Base.

Constructor

constructor(definition)

Parameters

definition {string}: definition

Structural methods

setCallback(name,callback,context)

Parameters

name {string}: name
callback {function}: callback
context {object}: context

Returns

{Transformer}

Throws

{TypeError} value is not a string
{TypeError} value is not a function

Other methods

run(value)

Parameters

value {*}: value

Returns

Throws

{Error} unknown command
{TypeError} unsupported type
{Error} type not supported

Events

This component does not fire any public events. It may fire events that are inherited from its parent classes.

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