esstringbuilderplus

ECMAScript String Builder PLUS

es-stringbuilder-plus delivers a way to build a string (actually a wrapped String instance delivering a mutable string value).

Instances can use native String methods and a number of custom methods to change their internal value without the need for re-assigning.

ECMAScript (ES) string builder PLUS is programmed in a class free object oriented way.

DEMO & Tests

Also on NPM

All custom instance getters and methods

Notes

• The code follows ES20XX, so will work with all up to date modern browsers and/or within later nodejs versions.
• All (not deprecated) native String methods (e.g. toUpperCase) are converted and usable in the same way you would use them for a regular string.
• A string builder instance can be created using the imported 'constructor' (let's call it $SB). $SB can be called either as a regular function (e.g. $SB("some string")) or as a tagged template (e.g $SB`some string` ). It can only receive a String or a Number. Any other parameter type will result in an instance with an empty string as its value.
• ES String Builder PLUS is a lightweight stand alone module. We also have the more comprehensive es-string-fiddler module available. That module delivers more functionality, e.g. methods to sanitize HTML strings, create Regular Expressions from multiline strings and extend the constructor with ones own custom methods.
• In the following the custom getters and methods of an instance are described.
  • With 'value' the current value of a string builder instance is meant.
  • Value changing (mutating) getters and methods of an instance and the results of native String method calls are 'chainable'.
  • Chainable means the result can be followed by a new getter-/method-call (e.g. [instance].toUpperCase().quot("[,]")).
• The constructor enables creating user defined extensions, using [constructor].addExtension.
  • syntax: [constructor]..addExtension(name: string, function(me: instance, [...arguments]) {...}): function)
    when ...arguments is empty, the extension will be a getter. Otherwise it will be a method. The first parameter is the instance to apply the extension function to. It is obligatory and must always be the first argument of the extension function. The return value of the extension function may be a string or the (modified) instance. The user defined extension method for an instance returns itself. Thus it is is always chainable.
  • example 1 ($SB is the constructor):
    $SB.addExtension(`sayOk`, me => me.prepend(`*OK* `));
sayOk is now a getter const test = $SB`test123`.sayOk => test.value: "*OK * test123"
  • example 2:
    $SB.addExtension(`replaceFirstWord`, (me, replacement) =>
    (me.indexOf(" ") ? replacement : "" ) + me.value.slice(me.indexOf(` `));
const test = $SB`test123 4567`.replaceFirstWord(`123`) => test.value => "123 456"
    const test = $SB`test1234567`.replaceFirstWord(`123`) => test.value => "test123456"

---

• append(str2Append) [mutates, chainable] Appends [str2Append] to the value.

• as(newValue) [mutates, chainable] alias for [instance].is.

• clear [getter, mutates, chainable] Clears the value - effectively rendering it to an empty string.

• clone [getter, chainable] Creates a clone of the instance.

• cloneWith(value: string or template string) [chainable] Creates a clone of the instance. Either re-assign to a new value, or use as intermediate value.

• empty [getter, mutates, chainable] Alias of clear. Clears the value, effectively rendering it to an empty string.

• firstUp [getter, mutates, chainable] Convert the first letter of the value to uppercase.

• indexOf(stringToFindIndexOf: string|RegExp, [startPosition]: int) [native (override), returns a value (not mutating)]
  Returns the (zero based) index of the substring to find (optional starting at [startPosition])
  or undefined (instead of -1) when nothing was found. Furthermore [stringToFindIndexOf] may be a regular expression.

• initial [getter, returns a value (not mutating)] Retrieves the value the instance was instantiated with (see also reset).

• interpolate(...replacementTokens) [mutates, chainable] Interpolates terms from the value with one or more replacement objects ([replacementTokens]). see the GitHub StringInterpolator library or the demo for how to use.

• is(newValue: string/template string)) [mutates, chainable] Assigns [newValue] to the value.

  Notes:

  • [instance].is(...) will not change the initial instance value (which is stored for use in [instance].reset).
  • to re-assign the instance value one can also use the setter [instance].value = ...

• lastIndexOf(stringToFindIndexOf: string|RegExp, [beforePosition]: int) [native (override), returns a value (not mutating)]
  Returns the (zero based) index of the substring to find (optional before [beforePosition] in the string)
  or undefined (instead of -1) when nothing was found. Furthermore [stringToFindIndexOf] may be a regular expression.

• prepend(str2Prepend: string/template string) [mutates, chainable] inserts [str2Prepend] before the value.

• quot(quotes = '"') [mutates, chainable] Adds [quotes] to the start and end of the value. [quotes] can be one character, or a string of two comma separated characters/string (e.g. "[,]" or "*start*,*end*").

• quot4Print(quotes = '"') [returns a value (not mutating)] Equal to quot, but will not change the value.
  This will return the value surrounded with the given [quotes], e.g. for printing to screen.

• remove(start: number, end: number) [mutates, chainable] Removes the part of the value from [start] to [end]. If neither [start] and/or [end] are given, nothing will happen to the value. If one of [start] or [end] is not given, the defaults are respectively 0 or the length of the value.
  [end] can be negative (meaning [end] characters from the end of the value).

• reset [getter, mutates, chainable] Sets the value back to the value the instance was instantiated with.

• surroundWith({r: string (default ""), [r: string (default "")]}) [mutates, chainable]
  Surround the value with strings from [l](eft) and [r](ight).

• reverse [getter, mutates, chainable] Reverses the value (e.g. hello => olleh). Including strings containing Unicode 'surrogate pairs'

• toCamel [getter, mutates, chainable] converts a value with pattern aaa-bbb to camelCased notation (aaaBbb).

• toDashed [getter, mutates, chainable] converts a value with pattern aaaBbbCcc to dashed notation (aaa-bbb-ccc)

• toLower [getter, mutates, chainable] alias for String.prototype.toLowerCase.

• toUpper [getter, mutates, chainable] alias for String.prototype.toUpperCase.

• truncate(at:number, { html = false, wordBoundary = false } = {} ) [mutates, chainable] Truncates the value from its start to [at] and adds either ... ([html] false) or &hellip ([html] true) to it. When [wordBoundary] is true, truncates at the last word within the truncated result.

• value [getter, setter (mutates)] Retrieves the actual instance value or sets it.

• wordsUp [getter, mutates, chainable] converts all first letters of words within the value to uppercase