Transforms a List of Objects into a CSV List of Strings

Purpose of this simple library is to take a header and a list of objects and transform them into a CSV (Comma Separated Values) list of strings compatible with RFC 4180

CSV format is popular as an interchange format for spreadsheets

This library has been written with (old) browsers in mind and does not offer as many options and variations as many other related libraries offer (but for some which failed to transpile correctly for some reason... and drove us to write our own)

It implements RFC 4180 format as closely as possible

It also offers some helper functions which would help write a fairly easy different implementation of the builder as proposed in the next section

CSV Builder

makeCsvList(headers, objectList, options)

Takes two arrays: headers, a list of CSV header strings which are both header fields and property keys to objects. And objectList is the list of objects whose values corresponding to properties are values

This means only properties found in headers will bring values to the CSV result, other properties will be ignored. Also undefined properties will be assigned a empty value in the CSV result

This function returns a list of strings, each string representing a line of the CSV file, first line being composed of headers and subsequent lines contain values. Those lines are not finished with any specific end of line (normally CR/LF), this allowing user to define which one they prefer (LF, CR/LF...)

Parameters options is an optional object with the following optional properties:

• separator is meant to be a string defining the value separator for a CSV record, if separator is defined only the first character is taken into account. Default value is comma (,)
• fullDQuote directs use of enclosing quotes ("): if true, it encloses every value, otherwise it only encloses values which need enclosing (values with double quote, CR, LF, separators inside). Default is false

Note: list of headers has been deemed safer instead of drawing this list from objects properties directly because there is not always a defined and constant order of properties in objects (it is implementation dependent as ECMAScript works in old browsers and a matter of certain controversy)

Example

const { makeCsvList } = require("@labzdjee/obj-list-to-csv");
const headers = ["a", "b", "c"];
const objects = [
 { a: "A1", b: "B1", c: "C1" },
 { a: "A2", b: "B2", c: "C2" },
 { a: "A3, Alice", b: "B3, Bob", c: "C3, Cathy" },
];
const csv = makeCsvList(headers, objects);

Returned csv string array will contain this:

["a,b,c",
  "A1,B1,C1",
  "A2,B2,C2",
  "\"A3, Alice\",\"B3, Bob\",\"C3, Cathy\""]

Low Level Functions

Those helper functions can be used as primitives for building other CSV builders for different usages

escapeSpecialCharacters(inputString, separator = ",")

Takes a string (inputString) and returns a string with double-quote (") escaped

Return value is an object with following properties:

• return: value of string without surrounding double-quotes even if needed
• shouldEnclose: true if separator, carriage return or line feed included in inputString, false otherwise.

Naturally, separator is meant to be the value separator for a CSV record, if separator is defined only the first character is taken into account. If no such first character can be found, default value (a comma) is used

stringOrNumberToString(input, radix = 10)

Takes an input and returns it as a string only if input is already a string or a number, returns null otherwise

If input is a number, transforms it to a string with the provided radix (a number between 2 and 36, inclusively, representing the base for representing a numeric value)