The utils module — CasperJS 1.1.0-DEV documentation

# The `utils` module

This module provides simple helper functions, some of them being very specific to CasperJS though.

## Functions reference

Usage is pretty much straightforward:

    var utils = require('utils');

    utils.dump({plop: 42});

### `betterTypeOf()`

Signature: `betterTypeOf(input)`

Provides a better `typeof` operator equivalent, eg. able to retrieve the `Array` type.

### `betterInstanceOf()`

New in version 1.1.

Signature: `betterInstanceOf(input, constructor)`

Provides a better `instanceof` operator equivalent, is able to retrieve the `Array` instance or to deal with inheritance.

### `dump()`

Signature: `dump(value)`

Dumps a JSON representation of passed argument to the standard output. Useful for debugging your scripts.

### `fileExt()`

Signature: `fileExt(file)`

Retrieves the extension of passed filename.

### `fillBlanks()`

Signature: `fillBlanks(text, pad)`

Fills a string with trailing spaces to match `pad` length.

### `format()`

Signature: `format(f)`

Formats a string against passed args. `sprintf` equivalent.

Note

This is a port of nodejs `util.format()`.

### `getPropertyPath()`

Signature: `getPropertyPath(Object obj, String path)`

New in version 1.0.

Retrieves the value of an Object foreign property using a dot-separated path string:

    var account = {
        username: 'chuck',
        skills: {
            kick: {
                roundhouse: true
            }
        }
    }
    utils.getPropertyPath(account, 'skills.kick.roundhouse'); // true

Warning

This function doesn’t handle object key names containing a dot.

### `inherits()`

Signature: `inherits(ctor, superCtor)`

Makes a constructor inheriting from another. Useful for subclassing and extending.

Note

This is a port of nodejs `util.inherits()`.

### `isArray()`

Signature: `isArray(value)`

Checks if passed argument is an instance of `Array`.

### `isCasperObject()`

Signature: `isCasperObject(value)`

Checks if passed argument is an instance of `Casper`.

### `isClipRect()`

Signature: `isClipRect(value)`

Checks if passed argument is a `cliprect` object.

### `isFalsy()`

Signature: `isFalsy(subject)`

New in version 1.0.

Returns subject falsiness.

### `isFunction()`

Signature: `isFunction(value)`

Checks if passed argument is a function.

### `isJsFile()`

Signature: `isJsFile(file)`

Checks if passed filename is a Javascript one (by checking if it has a `.js` or `.coffee` file extension).

### `isNull()`

Signature: `isNull(value)`

Checks if passed argument is a `null`.

### `isNumber()`

Signature: `isNumber(value)`

Checks if passed argument is an instance of `Number`.

### `isObject()`

Signature: `isObject(value)`

Checks if passed argument is an object.

### `isString()`

Signature: `isString(value)`

Checks if passed argument is an instance of `String`.

### `isTruthy()`

Signature: `isTruthy(subject)`

New in version 1.0.

Returns subject truthiness.

### `isType()`

Signature: `isType(what, type)`

Checks if passed argument has its type matching the `type` argument.

### `isUndefined()`

Signature: `isUndefined(value)`

Checks if passed argument is `undefined`.

### `isWebPage()`

Signature: `isWebPage(what)`

Checks if passed argument is an instance of native PhantomJS’ `WebPage` object.

### `mergeObjects()`

Signature: `mergeObjects(origin, add[, Object opts])`

Merges two objects recursively.

Add `opts.keepReferences` if cloning of internal objects is not needed.

### `node()`

Signature: `node(name, attributes)`

Creates an (HT|X)ML element, having optional `attributes` added.

### `serialize()`

Signature: `serialize(value)`

Serializes a value using JSON format. Will serialize functions as strings. Useful for debugging and comparing objects.

### `unique()`

Signature: `unique(array)`

Retrieves unique values from within a given `Array`.