simple-common-utils

This is a collection of utility classes used for JS development.

1. Usage
2. Version history

Usage

1. ArrayStringifier
2. DottedStringObject
3. StaticUtils

ArrayStringifier

Given an array, produces its string representation.

import { ArrayStringifier } from "simple-common-utils"; 

• constructor()

  Constructs a class instance.

   new ArrayStringifier(array);
  

  gives exactly the same result as

   new ArrayStringifier()
       .setArray(array)
       .setSeparator(", ");
  

• process() / toString()

  Returns a string representation of the array.

The following methods return this for method chaining.

• setPrefix()

  Sets a prefix to be added to the resulting string.

   arrayStringifier.setPrefix(
       prefix, // String.
       addIfArrayLength // Boolean. If true the prefix will be added ONLY if the array is not empty. Default: true.
   );
  

• setArray()

  Sets an array to stringify.

   arrayStringifier.setArray(array);
  

• setSeparator()

  Sets a separator to be used.

   arrayStringifier.setSeparator(
       separator // String
   );
  

• setElementProcessor()

  Sets an element processor for fine-grained per-element processing. An element processor is a function the return value of which will be used to determine the value and optionally the separator for the current array element. If an element processor returns an object with methods getElement() and getSeparator() they will be used to get the value and the separator for the current array element. If the method getElement() is not present in the return value, the latter will be used as the value for the current array element as is and the separator set by setSeparator() will be used.

   const arrayStringifier = new ArrayStringifier();
   
   arrayStringifier
       .setArray([1, 2, 3, 4])
       .setElementProcessor(element => element % 2 ? "Something odd" : element)
       .process(); // Something odd, 2, Something odd, 4
   
   arrayStringifier
       .setArray([1, 2, 3, 4])
       .setElementProcessor(element => !(element % 2) ? element : element == 1 ? {
           getElement() {
               return "";
           },
           getSeparator() {
               return "";
           }
       } : "Something odd")
       .process(); // 2, Something odd, 4
  

• setPostfix()

  Sets a postfix to be added to the resulting string.

   arrayStringifier.setPostfix(
       postfix, // String.
       addIfArrayLength // Boolean. If true the postfix will be added ONLY if the array is not empty. Default: true.
   );
  

DottedStringObject

Provides a way to get and set objects properties with dot separated strings. All methods are static.

import { DottedStringObject } from "simple-common-utils";

• getProperty()

  Gets a property value.

   DottedStringObject.getProperty(
       object, // Object.
       fullPropertyName, // String. A dot separated full property name.
       defaultValue // Object. This value is returned if the property doesn't exist.
   );
  

  Example:

   const const obj = {
       f1: 10,
       obj1: {
           f1: 20
       }
   };
   
   DottedStringObject.getProperty(obj, "f1"); // 10
   DottedStringObject.getProperty(obj, "f1", "aaa"); // 10
   DottedStringObject.getProperty(obj, "obj1.f1"); // 20
   DottedStringObject.getProperty(obj, "obj1.f2", "default"); // default
  

• setProperty()

  Sets a property value.

   DottedStringObject.setProperty(
       object, // Object.
       fullPropertyName, // String. A dot separated full property name.
       value // Object. A value to set.
   );
  

  Example:

   const obj = {};
   
   DottedStringObject.setProperty(obj, "f1", 10); // { f1: 10 }
   DottedStringObject.setProperty(obj, "obj1", 20); // { f1: 10, obj1: 20 }
   DottedStringObject.setProperty(obj, "obj1", {}); // { f1: 10, obj1: {} }
   DottedStringObject.setProperty(obj, "obj1.f2", 30); // { f1: 10, obj1: { f2: 30 } }
  

StaticUtils

A collection of different utility methods. All the methods in this class are static.

import { StaticUtils } from "simple-common-utils";

• round()

  Rounds value to decimals digits after the decimal point (thanks, MarkG!). symmetric is used to achieve the same functionality both for negative and positive numbers.

   StaticUtils.round(value, decimals, symmetric);
  
   StaticUtils.round(10.2); // 10.2
   StaticUtils.round(10.2, 0); // 10
   StaticUtils.round(10.5, 0); // 11
   StaticUtils.round(10.523, 1); // 10.5
   StaticUtils.round(10.525, 2); // 10.53
   StaticUtils.round(-1.5, 0); // -1
   StaticUtils.round(-1.5, 0, true); // -2
  

• encodedUtf8ToByteArray()

  Converts the passed utf8-encoded string to a byte array.

   import utf8 from "utf8";
   
   StaticUtils.encodedUtf8ToByteArray(
       utf8.encode("abcфыва")); // [ 97, 98, 99, 209, 132, 209, 139, 208, 178, 208, 176 ]
  

• ensureBounds()

  Ensures min <= value <= max.

   StaticUtils.ensureBounds(value, min, max);
   
   StaticUtils.ensureBounds(10, 2, 18); // 10
   StaticUtils.ensureBounds(100, 2, 18); // 18
   StaticUtils.ensureBounds(100, 200, 1800); // 200
  

• pushAndReturnElement()

  Pushes element to array and returns element.

   StaticUtils.pushAndReturnElement(array, element);
  

• quoteIfString()

  Quotes value if it's a string, using quotingSymbol.

   StaticUtils.quoteIfString(10); // 10
   StaticUtils.quoteIfString("10"); // "10"
   StaticUtils.quoteIfString("10", "'"); // '10'
  

• safeQuoteIfString()

  Invokes quoteIfString() passing value and quotingSymbol to it if quoteIfString is true.

   StaticUtils.safeQuoteIfString(value, quoteIfString, quotingSymbol);
  

• objectToArray()

  Converts object to an array and returns it. Nested objects are not parsed.

   StaticUtils.objectToArray({a: "10", b: 20}); // [ '10', 20 ]
   StaticUtils.objectToArray({a: "10", b: 20, c: {a: 10}}); //  [ '10', 20, { a: 10 } ]
  

The code is taken from here for the next two methods.

• escapeRegExp()

  Given a string, escapes all occurences of symbols that have special meaning in regular expressions.

   StaticUtils.escapeRegExp("a"); // a
   StaticUtils.escapeRegExp("*a^"); // \*a\^
  

• replaceAll()

  Implements a "replace all" functionality for a string.

   StaticUtils.replaceAll("abc", "b", "10"); // a10c
   StaticUtils.replaceAll("a^b*c", "^b", "10"); // a10*c
  

• deg2Rad()

  Converts degrees to radians.

• color()

   StaticUtils.color("pink"); // 0xffc0cb00
   
   StaticUtils.color("non-existent-color"); // undefined
   
   StaticUtils.color(123); // 123
  

• random()

  Generates a random number using Math.random().

   StaticUtils.random(1.5, 2.5); // A random number between 1.5 and 2.5.
   
   StaticUtils.random(10, 12, true); // An integer random number in the half-open range [10, 12).
   
   StaticUtils.random(10, 12, true, true); // An integer random number in the closed-range [10, 12].
  

• verify(condition, errorMessage)

  Evaluates the passed boolean condition and throws an error with the errorMessage text if condition is false.

Version history

Version number	Changes
v1.5.1	quotingSymbol is added to StaticUtils.quoteIfString() / safeQuoteIfString().
v1.4.1	The method StaticUtils.verify() is added.
v1.2.1	StaticUtils.colorNames had 00 as alpha. Changed to FF.
v1.2.0	The parameter symmetric is added to StaticUtils.round() in a backwards-compatible way.
v1.1.0	The methods StaticUtils.deg2Rad() and StaticUtils.color() are added.
v1.0.0	Initial release.

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