formatter

This is a simple library designed to do one thing and one thing only - replace variables in strings with variable values. It is built in such a way that the formatter strings are parsed and you are provided with a function than can efficiently be called to provide the custom output.

NOTE: Formatter is not designed to be a templating library and if you are already using something like Handlebars or hogan in your library or application stack consider using them instead.

For example:

// create the "I like food formatter"
var likefood = formatter('I like {{ 0 }}, {{ 0 }} is excellent and kicks the pants off {{ 1 }}.');

// I can then log out how much I like bacon
console.log(likefood('bacon', 'bread'));

If you have a look at your console output, you should see the following:

I like bacon, bacon is excellent and kicks the pants off bread.

Using named variables

In the examples above we saw how the formatter can be used to replace function arguments in a formatter string. We can also set up a formatter to use particular key values from an input string instead if that is more suitable:

// create the "I like food formatter" (named style)
var likefood = formatter('I like {{ great }}, {{ great }} is excellent and kicks the pants off {{ poor }}.');

// I can then log out how much I like bacon
console.log(likefood({ great: 'bacon', poor: 'bread' }));

This will yield the same output as our first example.

Nested Property Values

Since version 0.1.0 you can also access nested property values, as you can with templates like handlebars.

Performance

I've done some performance benchmarks and formatter is faster than handlebars, but that isn't surprising as it is far simpler and doesn't have the smarts of HBS. The test is really there to ensure that I didn't do anything too silly...

Additionally, it should be noted that using formatter is 100% slower than concatenating strings, so don't use it where performance is critical. Do use it where not repeating yourself is.

Modifiers

Length Modifier (len)

The length modifier is used to ensure that a string is exactly the length specified. The string is sliced to the required max length, and then padded out with spaces (or a specified character) to meet the required length.

// pad the string test to 10 characters
formatter('{{ 0|len:10 }}')('test');   // 'test      '

// pad the string test to 10 characters, using a as the padding character
formatter('{{ 0|len:10:a }}')('test'); // 'testaaaaaa'