I recently developed some code that required the use of dojo.string.substitute. I have used this module before but I never really researched it’s full potential. I understand it is the basis for Dojo’s Dijit templating. I needed to know more…

Overview

The function performs parameterized substitutions on a string template.

Method Signature

string.substitute(template, map, transform, scope)
template String a string with expressions in the form ${key} to be replaced or ${key:format} which specifies a format function. keys are case-sensitive.
map Object|Array hash to search for substitutions
transform Function a function to process all parameters before substitution takes place
scope Object where to look for optional format function; default to the global namespace

Usage

The string template is written as a regular string with ${} expression in the place where a substitution is required. ${} expression references a position in an Array or a member of an Object structure.
The method can be used a number of ways.

with Array

- substitutes expressions in a string with values from an Array.

with Object

- substitutes expressions in a string with values from a JSON Object.

Object and Transformer

- substitutes expressions in a string with values from a JSON Object, but uses a transformer to modify the text before rendering.

Object and Formatter

- substitutes expressions in a string with values from a JSON Object, but uses the dojo.string module as a formatter.