Using the command line
CasperJS ships with a built-in command line parser on top of PhantomJS' one, located in the cli
module; it exposes passed arguments as positional ones and named options
But no worries for manipulating the cli
module parsing API, a Casper
instance always contains a ready to use cli
property, allowing easy access of all these parameters.
Let's consider this simple casper script:
var casper = require("casper").create(); casper.echo("Casper CLI passed args:"); require("utils").dump(casper.cli.args); casper.echo("Casper CLI passed options:"); require("utils").dump(casper.cli.options); casper.exit();
Note
Please note the two casper-path
and cli
options; these are passed to the casper script through the casperjs
Python executable.
Execution results:
$ casperjs test.js arg1 arg2 arg3 --foo=bar --plop anotherarg Casper CLI passed args: [ "arg1", "arg2", "arg3", "anotherarg" ] Casper CLI passed options: { "casper-path": "/Users/niko/Sites/casperjs", "cli": true, "foo": "bar", "plop": true }
Getting, checking or dropping parameters:
var casper = require("casper").create(); casper.echo(casper.cli.has(0)); casper.echo(casper.cli.get(0)); casper.echo(casper.cli.has(3)); casper.echo(casper.cli.get(3)); casper.echo(casper.cli.has("foo")); casper.echo(casper.cli.get("foo")); casper.cli.drop("foo"); casper.echo(casper.cli.has("foo")); casper.echo(casper.cli.get("foo")); casper.exit();
Execution results:
$ casperjs test.js arg1 arg2 arg3 --foo=bar --plop anotherarg
true
arg1
true
anotherarg
true
bar
false
undefined
Hint
What if you want to check if any arg or option has been passed to your script? Here you go:
// removing default options passed by the Python executable casper.cli.drop("cli"); casper.cli.drop("casper-path"); if (casper.cli.args.length === 0 && Object.keys(casper.cli.options).length === 0) { casper.echo("No arg nor option passed").exit(); }
casperjs native options
The casperjs command has three available options:
-
--verbose
: to prints out log messages to the console -
--log-level=[debug|info|warning|error]
to set the :ref:`logging level <logging>` -
-
--engine=[phantomjs|slimerjs]
to select the browser engine you want to use. CasperJS -
supports PhantomJS (default) that runs Webkit, and SlimerJS that runs Gecko.
-
Example:
$ casperjs --verbose --log-level=debug myscript.js
Last but not least, you can still use all PhantomJS standard CLI options as you would do with any other phantomjs script:
$ casperjs --web-security=no --cookies-file=/tmp/mycookies.txt myscript.js
Hint
To remember what the native phantomjs available cli options are, run the phantomjs --help
command.
SlimerJS supports almost same options as PhantomJS.
Raw parameter values
By default, the cli object will process every passed argument & cast them to the appropriate detected type; example script:
var casper = require('casper').create(); var utils = require('utils'); utils.dump(casper.cli.get('foo')); casper.exit();
If you run this script:
$ casperjs c.js --foo=01234567
1234567
As you can see, the 01234567
value has been cast to a Number.
Sometimes, you just want the original string; then you can use the raw
property of the cli
object, which contains the raw values passed parameters:
var casper = require('casper').create(); var utils = require('utils'); utils.dump(casper.cli.get('foo')); utils.dump(casper.cli.raw.get('foo')); casper.exit();
Sample usage:
$ casperjs c.js --foo=01234567
1234567
"01234567"