Using the command line¶
CasperJS ships with a built-in command line parser on top of PhantomJS’ parser, located in the cli
module. It exposes passed arguments as positional ones and named options
A Casper
instance always contains a ready-to-use cli
property for easy access to these parameters, so you don’t have to worry about manipulating the cli
module parsing API.
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¶
New in version 1.1.
The casperjs command has three available options:
--direct
: to print out log messages to the console--log-level=[debug|info|warning|error]
to set the logging level--engine=[phantomjs|slimerjs]
to select the browser engine you want to use. CasperJS supports PhantomJS (default) that runs Webkit, and SlimerJS that runs Gecko.
Warning
Deprecated since version 1.1.
The --direct
option has been renamed to --verbose
. Although --direct
will still work, it is now considered deprecated.
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 cli options are available, run the phantomjs --help
command.
SlimerJS supports almost same options as PhantomJS.
Raw parameter values¶
New in version 1.0.
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.
If you want the original string, use the raw
property of the cli
object, which contains the raw values of the 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"