try-these(function)

This is a port of the PrototypeJS method Try.these. It accepts an arbitrary number of functions and returns the result of the first one that doesn't throw an error. try-these provides a simple idiom for trying out blocks of code in sequence. Such a sequence of attempts usually represents a downgrading approach to obtaining a given feature.

Installation

npm install try-these

Usage

var tryThese = require('try-these');

var XHR = tryThese(
    function() { return new XMLHttpRequest() },
    function() { return new ActiveXObject('Msxml2.XMLHTTP') },
    function() { return new ActiveXObject('Microsoft.XMLHTTP') }
) || false;

In the above example, we want to get an XMLHttpRequest object.

try-these will try several ways in sequence, from the best (and, theoretically, most widespread) one to the oldest and rarest way, returning the result of the first successful function.

If none of the blocks succeeded, try-these will return undefined, which will cause the XHR variable in the example above to return false, provided as a fallback result value.

Tests

npm test

Contributing

In lieu of a formal style guide, take care to maintain the existing coding style. Add unit tests for any new or changed functionality. Lint and test your code. See the CONTRIBUTING file for more detailed information.