hokey-cokey

Hokey Cokey! Simple string template rendering and parameter value extracting

Hokey Cokey is a quick tool for extracting parameters from, and inserting parameters into, template strings:

Extract:

• Match a target string against a template e.g. places/france/paris and places/:country/{city}
• Return an object listing found values e.g. { country: "france", city: "paris" }

Render:

• Take a template string and merge in some values e.g. places/${country}/:city and { country: "france", city: "paris" }
• Return the rendered string after variables have been inserted e.g. places/france/paris

Things to know:

• Works with parameters in :express, {jsx}, {{handlebars}} or ${es6} format.
• Doesn't do anything complicated (like RegExp patterns, * glob patterns, or optional parameters).
• Parameter names must match the simple format [a-zA-Z][a-zA-Z0-9].
• When extracting values the template must have one character between each template parameter.
• Template destructuring is cached internally for performance.
• Well unit-tested and 100% covered.
• Useful for cases where RegExps are too fussy and you want something chunky and robust.

Installation

npm install hokey-cokey

Usage

extract(template: string, target: string) Extract values from a string

Extracts a set of values out of a target string based on a template string.

• template must be a string containing one or more parameters in any allowed format
• Returns an object in parameter: value format

const { extract } = require('hokey-cokey');

// Extract the values.
extract("places/{country}/{city}", "places/france/paris"); // { country: "france", city: "paris" }
extract("places/:country/:city", "places/france/paris"); // { country: "france", city: "paris" }

render(template, values) Inject values into a template

Render a set of values into a template string.

• template must be a string containing one or more parameters in any allowed format
• values can be:
  • An object containing string or function keys (keys must correspond to parameters in the template or render will fail)
  • A function called for each parameter (receives the parameter name)
  • A single string used for all parameters
• Returns the rendered string

const { render } = require("hokey-cokey");

// Render the template with an object.
render("blogs-:category-:slug", { category: "cheeses", slug: "stilton" }); // blogs-cheeses-stilton
render("blogs-:category-:slug", "Arrrrgh"); // blogs-Arrrrgh-Arrrrgh
render("blogs-:category-:slug", (p) => p.toUpperCase()); // blogs-CATEGORY-SLUG

params(template) Get parameter names from template string

Parse a template string and return an array of found variables that were found.

• template must be a string containing one or more parameters in any allowed format
• Returns an array of string parameter names that were found in the template

const { params } = require("hokey-cokey");

// Extract the parameter names.
params("{username}@{domain}"); // ["username", "domain"]
params(":name // ${age}"); // ["name", "age"]