28 KiB
SilverStripe Integration for Behat
Overview
Behat is a testing framework for behaviour-driven development. Because it primarily interacts with your website through a browser, you don't need any specific integration tools to get it going with a basic SilverStripe website, simply follow the standard Behat usage instructions.
This extension comes in handy if you want to go beyond interacting with an existing website and database, for example make changes to your database content which would need to be rolled back to a "clean slate" later on.
It provides the following helpers:
- Provide access to SilverStripe classes in your Behat contexts
- Set up a temporary database automatically
- Reset the database content on every scenario
- Prebuilt Contexts for SilverStripe's login forms and other common tasks
- Creating of member fixtures with predefined permissions
- YML fixture definitions inside your Behat scenarios
- Waiting for jQuery Ajax responses (rather than fixed wait timers)
- Captures JavaScript errors and logs them through Selenium
- Saves screenshots to filesystem whenever an assertion error is detected
In order to achieve this, the extension makes one basic assumption: Your Behat tests are run from the same application as the tested SilverStripe codebase, on a locally hosted website from the same codebase. This is important because we need access to the underlying SilverStripe PHP classes. You can of course use a remote browser to do the actual testing.
Note: The extension has only been tested with the selenium2
Mink driver.
Installation
Simply install SilverStripe through Composer. Skip this step if adding the module to an existing project.
composer create-project silverstripe/installer my-test-project 3.1.x-dev
Switch to the newly created webroot, and add the SilverStripe Behat extension.
cd my-test-project
composer require "silverstripe/behat-extension:*"
Now get the latest Selenium2 server (requires Java):
wget https://selenium.googlecode.com/files/selenium-server-standalone-2.39.0.jar
On OSX, you can also use Homebrew: brew install selenium-server-standalone
.
If you are having issues running Selenium with your browser please check
that you're on the latest driver,
since the download link above might be out of date.
Now install the SilverStripe project as usual by opening it in a browser and following the instructions.
Protip: You can skip this step by using [SS_DATABASE_CHOOSE_NAME]
in a global
_ss_environment.php
file one level above the webroot.
Unless you have $_FILE_TO_URL_MAPPING
set up, you also need to specify the URL for your webroot. Either add it to the existing behat.yml
configuration file
in your project root, or set is as an environment variable in your terminal session:
export BEHAT_PARAMS="extensions[SilverStripe\BehatExtension\MinkExtension][base_url]=http://localhost/"
Usage
Starting the Selenium Server
You can run the server locally in a separate Terminal session:
java -jar selenium-server-standalone-2.39.0.jar
Running the Tests
Now you can run the tests (for example for the framework
module):
vendor/bin/behat @framework
In order to run specific tests only, use their feature file name:
vendor/bin/behat @framework/login.feature
This will start a Firefox browser by default. Other browsers and profiles can be configured in behat.yml
.
For example, if you want to start a Chrome Browser you can following the instructions provided here.
Tutorials
Configuration
The SilverStripe installer already comes with a YML configuration
which is ready to run tests on a locally hosted Selenium server,
located in the project root as behat.yml
.
You'll need to customize at least the base_url
setting to match the URL where
the tested SilverStripe instance is hosted locally. This
Generic Mink configuration settings are placed in SilverStripe\BehatExtension\MinkExtension
,
which is a subclass of Behat\MinkExtension\Extension
.
Overview of settings (all in the extensions.SilverStripe\BehatExtension\Extension
path):
framework_path
: Path to the SilverStripe Framework folder. It supports both absolute and relative (tobehat.yml
file) paths.extensions.Behat\MinkExtension\Extension.base_url
: You will probably need to change the base URL that is used during the test process. It is used every time you use relative URLs in your feature descriptions. It will also be used by file to URL mapping inSilverStripeExtension
.extensions.Behat\MinkExtension\Extension.files_path
: Change to support file uploads in your tests. Currently only absolute paths are supported.ajax_steps
: Because SilverStripe uses AJAX requests quite extensively, we had to invent a way to deal with them more efficiently and less verbose than just Optionalajax_steps
is used to match steps defined there so they can be "caught" by special AJAX handlers that tweak the delays. You can either use a pipe delimited string or a list of substrings that match step definition.ajax_timeout
: Milliseconds after which an Ajax request is regarded as timed out, and the script continues with its assertions to avoid a deadlock (Default: 5000).screenshot_path
: Absolute path used to store screenshot of a last known state of a failed step. Screenshot names within that directory consist of feature file filename and line number that failed.
Example: behat.yml
default:
context:
class: SilverStripe\MyModule\Test\Behaviour\FeatureContext
extensions:
SilverStripe\BehatExtension\Extension:
screenshot_path: %behat.paths.base%/artifacts/screenshots
SilverStripe\BehatExtension\MinkExtension:
# Adjust this to your local environment
base_url: http://localhost/
default_session: selenium2
javascript_session: selenium2
goutte: ~
selenium2:
browser: firefox
Module Initialization
You're all set to start writing features now! Simply create *.feature
files
anywhere in your codebase, and run them as shown above. We recommend the folder
structure of tests/behat/features
, since its consistent with the common location
of SilverStripe's PHPUnit tests.
Behat tests rely on a FeatureContext
class which contains step definitions,
and can be composed of other subcontexts, e.g. for SilverStripe-specific CMS steps
(details on behat.org).
Since step definitions are quite domain specific, its likely that you'll need your own context.
The SilverStripe Behat extension provides an initializer script which generates a template
in the recommended folder structure:
vendor/bin/behat --init @mymodule
You'll now have a class located in mymodule/tests/behat/features/bootstrap/Context/FeatureContext.php
,
as well as a folder for your features with mymodule/tests/behat/features
.
The class is namespaced, and defaults to the module name. You can customize this:
vendor/bin/behat --namespace='MyVendor\MyModule' --init @mymodule
In this case, you'll need to pass in the namespace when running the features as well (at least until SilverStripe modules allow declaring a namespace).
vendor/bin/behat --namespace='MyVendor\MyModule' @mymodule
Available Step Definitions
The extension comes with several BehatContext
subclasses come with some extra step defintions.
Some of them are just helpful in general website testing, other's are specific to SilverStripe.
To find out all available steps (and the files they are defined in), run the following:
vendor/bin/behat @mymodule --definitions=i
Note: There are more specific step definitions in the SilverStripe framework
module
for interacting with the CMS interfaces (see framework/tests/behat/features/bootstrap
).
In addition to the dynamic list, a cheatsheet of available steps can be found at the end of this guide.
Fixtures
Since each test run creates a new database, you can't rely on existing state unless you explicitly define it.
Database Defaults
The easiest way to get default data is through DataObject->requireDefaultRecords()
.
Many modules already have this method defined, e.g. the blog
module automatically
creates a default BlogHolder
entry in the page tree. Sometimes these defaults can
be counterproductive though, so you need to "opt-in" to them, via the @database-defaults
tag placed at the top of your feature definition. The defaults are reset after each
scenario automatically.
Inline Definition
If you need more flexibility and transparency about which records are being created, use the inline definition syntax. The following example shows some syntax variations:
Feature: Do something with pages
As an site owner
I want to manage pages
Background:
# Creates a new page without data. Can be accessed later under this identifier
Given a "page" "Page 1"
# Uses a custom RegistrationPage type
And an "error page" "Register"
# Creates a page with inline properties
And a "page" "Page 2" with "URLSegment"="page-1" and "Content"="my page 1"
# Field names can be tabular, and based on DataObject::$field_labels
And the "page" "Page 3" has the following data
| Content | <blink> |
| My Property | foo |
| My Boolean | bar |
# Pages are published by default, can be explicitly unpublished
And the "page" "Page 1" is not published
# Create a hierarchy, and reference a record created earlier
And the "page" "Page 1.1" is a child of a "page" "Page 1"
# Specific page type step
And a "page" "My Redirect" which redirects to a "page" "Page 1"
And a "member" "Website User" with "FavouritePage"="=>Page.Page 1"
@javascript
Scenario: View a page in the tree
Given I am logged in with "ADMIN" permissions
And I go to "/admin/pages"
Then I should see "Page 1" in CMS Tree
- Fixtures are created where you defined them. If you want the fixtures to be created before every scenario, define them in Background. If you want them to be created only when a particular scenario runs, define them there.
- Fixtures are cleared between scenarios.
- The basic syntax works for all
DataObject
subclasses, but some specific notations like "is not published" requires extensions likeHierarchy
to be applied to the class - Record types, identifiers, property names and property values need to be quoted
- Record types (class names) can use more natural notation ("registration page" instead of "Registration Page")
- Record types support the
$singular_name
notation which is also used to reference the types throughout the CMS. Record property names support the$field_labels
notation in the same fashion. - Property values may also use a
=>
symbol to indicate relationships between records. The notation is=><classname>.<identifier>
. Forhas_many
ormany_many
relationships, multiple relationships can be separated by a comma.
Writing Behat Tests
Directory Structure
As a convention, SilverStripe Behat tests live in a tests/behat
subfolder
of your module. You can create it with the following command:
mkdir -p mymodule/tests/behat/features/bootstrap/MyModule/Test/Behaviour
FeatureContext
The generic Behat usage instructions apply
here as well. The only major difference is the base class from which
to extend your own FeatureContext
: It should be SilverStripeContext
rather than BehatContext
.
Example: mymodule/tests/behat/features/bootstrap/MyModule/Test/Behaviour/FeatureContext.php
<?php
namespace MyModule\Test\Behaviour;
use SilverStripe\BehatExtension\Context\SilverStripeContext,
SilverStripe\BehatExtension\Context\BasicContext,
SilverStripe\BehatExtension\Context\LoginContext;
require_once 'PHPUnit/Autoload.php';
require_once 'PHPUnit/Framework/Assert/Functions.php';
class FeatureContext extends SilverStripeContext
{
public function __construct(array $parameters)
{
$this->useContext('BasicContext', new BasicContext($parameters));
$this->useContext('LoginContext', new LoginContext($parameters));
parent::__construct($parameters);
}
}
Screen Size
In some Selenium drivers like SauceLabs you can
define the desired browser window size through a capabilities
definition.
By default, Selenium doesn't support this though, so we've added a workaround
through an environment variable:
BEHAT_SCREEN_SIZE=320x600 vendor/bin/behat
Inspecting PHP sessions
Behat is executed from CLI, which in turn triggers web requests in a browser.
This browser session is associated PHP session information such as the logged-in user.
After every request, the session information is persisted on disk as part
of the TestSessionEnvironment
, in order to share it with Behat CLI.
Example: Retrieve the currently logged-in member
$env = Injector::inst()->get('TestSessionEnvironment');
$state = $env->getState();
if(isset($state->session['loggedInAs'])) {
$member = \Member::get()->byID($state->session['loggedInAs']);
} else {
$member = null;
}
FAQ
FeatureContext not found
This is most likely a problem with Composer's autoloading generator.
Check that you have "SilverStripe" mentioned in the vendor/composer/autoload_classmap.php
file,
and call composer dump-autoload
if not.
Why does the module need to know about the framework path on the filesystem?
Sometimes SilverStripe needs to know the URL of your site. When you're visiting your site in a web browser this is easy to work out, but if you're executing scripts on the command-line, it has no way of knowing.
To work this out, this module is using file to URL mapping.
How does the module interact with the SS database?
The module creates temporary database on init and is switching to the alternative
database session before every scenario by using /dev/tests/setdb
TestRunner
endpoint.
It also populates this temporary database with the default records if necessary.
It is possible to include your own fixtures, it is explained further.
Why do tests pass in a fresh installation, but fail in my own project?
Because we're testing the interface directly, any changes to the viewed elements have the potential to disrupt testing. By building a test database from scratch, we're trying to minimize this impact. Some examples where things can go wrong nevertheless:
- Thirdparty SilverStripe modules which install default data
- Changes to the default interface language
- Configurations which remove admin areas or specific fields
Currently there's no way to exclude offending modules from a test run. You either have to adjust the tests to work around these changes, or run tests on a "sandbox" projects without these modules.
How do I debug when something goes wrong?
First, read the console output. Behat will tell you which steps have failed.
SilverStripe Behaviour Testing Framework also notifies you about some events. It tries to catch some JavaScript errors and AJAX errors as well although it is limited to errors that occur after the page is loaded.
Screenshot will be taken by the module every time the step is marked as failed. Refer to configuration section above to know how to set up the screenshot path.
If you are unable to debug using the information collected with the above methods, it is possible to delay the step execution by adding the following step:
And I wait for "10000"
where 10000
is the number of millisecods you wish the session to wait.
It is very useful when you want to look at the error or developer console
inside the browser or if you want to interact with the session page manually.
Can I set breakpoints through XDebug?
If you have XDebug set up, breakpoints are your friend. The problem is that you can only connect the debugger to the PHP execution in the CLI, or in the browser, not both at the same time.
First of all, ensure that xdebug.remote_autostart
is set to Off
,
otherwise you'll always have an active debugging session in CLI, never in the browser.
Then you can choose to enable XDebug for the current CLI run:
XDEBUG_CONFIG="idekey=macgdbp" vendor/bin/behat
Or you can use the TESTSESSION_PARAMS
environment variable to pass additional
parameters to dev/testsession/start
, and debug in the browser instead.
TESTSESSION_PARAMS="XDEBUG_SESSION_START=macgdbp" vendor/bin/behat @app
The macgdbp
IDE key needs to match your xdebug.idekey
php.ini setting.
How do I use SauceLabs.com for remote Selenium2 testing?
Here's a sample profile for your behat.yml
:
# Saucelabs.com sample setup, use with "vendor/bin/behat --profile saucelabs"
saucelabs:
extensions:
SilverStripe\BehatExtension\MinkExtension:
selenium2:
browser: firefox
# Add your own username and API token here
wd_host: <user>:<api-token>@ondemand.saucelabs.com/wd/hub
capabilities:
platform: "Windows 2008"
browser: "firefox"
version: "15"
Cheatsheet
This is a manually categorized list of available commands
when both the cms
and framework
modules are installed.
It's based on the vendor/bin/behat -di @cms
output.
Basics
Then /^(?:|I )should see "(?P<text>(?:[^"]|\\")*)"$/
- Checks, that page contains specified text.
Then /^(?:|I )should not see "(?P<text>(?:[^"]|\\")*)"$/
- Checks, that page doesn't contain specified text.
Then /^(?:|I )should see text matching (?P<pattern>"(?:[^"]|\\")*")$/
- Checks, that page contains text matching specified pattern.
Then /^(?:|I )should not see text matching (?P<pattern>"(?:[^"]|\\")*")$/
- Checks, that page doesn't contain text matching specified pattern.
Then /^the response should contain "(?P<text>(?:[^"]|\\")*)"$/
- Checks, that HTML response contains specified string.
Then /^the response should not contain "(?P<text>(?:[^"]|\\")*)"$/
- Checks, that HTML response doesn't contain specified string.
Then /^(?:|I )should see "(?P<text>(?:[^"]|\\")*)" in the "(?P<element>[^"]*)" element$/
- Checks, that element with specified CSS contains specified text.
Then /^(?:|I )should not see "(?P<text>(?:[^"]|\\")*)" in the "(?P<element>[^"]*)" element$/
- Checks, that element with specified CSS doesn't contain specified text.
Then /^the "(?P<element>[^"]*)" element should contain "(?P<value>(?:[^"]|\\")*)"$/
- Checks, that element with specified CSS contains specified HTML.
Then /^(?:|I )should see an? "(?P<element>[^"]*)" element$/
- Checks, that element with specified CSS exists on page.
Then /^(?:|I )should not see an? "(?P<element>[^"]*)" element$/
- Checks, that element with specified CSS doesn't exist on page.
Then /^(?:|I )should be on "(?P<page>[^"]+)"$/
- Checks, that current page PATH is equal to specified.
Then /^the (?i)url(?-i) should match (?P<pattern>"([^"]|\\")*")$/
- Checks, that current page PATH matches regular expression.
Then /^the response status code should be (?P<code>\d+)$/
- Checks, that current page response status is equal to specified.
Then /^the response status code should not be (?P<code>\d+)$/
- Checks, that current page response status is not equal to specified.
Then /^(?:|I )should see (?P<num>\d+) "(?P<element>[^"]*)" elements?$/
- Checks, that (?P<num>\d+) CSS elements exist on the page
Then /^print last response$/
- Prints last response to console.
Then /^show last response$/
- Opens last response content in browser.
Then /^I should be redirected to "([^"]+)"/
Given /^I wait (?:for )?([\d\.]+) second(?:s?)$/
Navigation
Given /^(?:|I )am on homepage$/
- Opens homepage.
When /^(?:|I )go to homepage$/
- Opens homepage.
Given /^(?:|I )am on "(?P<page>[^"]+)"$/
- Opens specified page.
When /^(?:|I )go to "(?P<page>[^"]+)"$/
- Opens specified page.
When /^(?:|I )reload the page$/
- Reloads current page.
When /^(?:|I )move backward one page$/
- Moves backward one page in history.
When /^(?:|I )move forward one page$/
- Moves forward one page in history
Forms
When /^(?:|I )press "(?P<button>(?:[^"]|\\")*)"$/
- Presses button with specified id|name|title|alt|value.
When /^(?:|I )follow "(?P<link>(?:[^"]|\\")*)"$/
- Clicks link with specified id|title|alt|text.
When /^(?:|I )fill in "(?P<field>(?:[^"]|\\")*)" with "(?P<value>(?:[^"]|\\")*)"$/
- Fills in form field with specified id|name|label|value.
When /^(?:|I )fill in "(?P<value>(?:[^"]|\\")*)" for "(?P<field>(?:[^"]|\\")*)"$/
- Fills in form field with specified id|name|label|value.
When /^(?:|I )fill in the following:$/
- Fills in form fields with provided table.
When /^(?:|I )select "(?P<option>(?:[^"]|\\")*)" from "(?P<select>(?:[^"]|\\")*)"$/
- Selects option in select field with specified id|name|label|value.
When /^(?:|I )additionally select "(?P<option>(?:[^"]|\\")*)" from "(?P<select>(?:[^"]|\\")*)"$/
- Selects additional option in select field with specified id|name|label|value.
When /^I select the "([^"]*)" radio button$/
- Selects a radio button with the given id|name|label|value
When /^(?:|I )check "(?P<option>(?:[^"]|\\")*)"$/
- Checks checkbox with specified id|name|label|value.
When /^(?:|I )uncheck "(?P<option>(?:[^"]|\\")*)"$/
- Unchecks checkbox with specified id|name|label|value.
When /^(?:|I )attach the file "(?P[^"]*)" to "(?P<field>(?:[^"]|\\")*)"$/
- Attaches file to field with specified id|name|label|value.
Then /^the "(?P<field>(?:[^"]|\\")*)" field should contain "(?P<value>(?:[^"]|\\")*)"$/
- Checks, that form field with specified id|name|label|value has specified value.
Then /^the "(?P<field>(?:[^"]|\\")*)" field should not contain "(?P<value>(?:[^"]|\\")*)"$/
- Checks, that form field with specified id|name|label|value doesn't have specified value.
Then /^the "(?P<checkbox>(?:[^"]|\\")*)" checkbox should be checked$/
- Checks, that checkbox with specified in|name|label|value is checked.
Then /^the "(?P<checkbox>(?:[^"]|\\")*)" checkbox should not be checked$/
- Checks, that checkbox with specified in|name|label|value is unchecked.
Given /^(?:|I )attach the file "(?P[^"]*)" to "(?P<field>(?:[^"]|\\")*)" with HTML5$/
When /^I fill in the "(?P<field>([^"]*))" HTML field with "(?P<value>([^"]*))"$/
When /^I fill in "(?P<value>([^"]*))" for the "(?P<field>([^"]*))" HTML field$/
When /^I append "(?P<value>([^"]*))" to the "(?P<field>([^"]*))" HTML field$/
Then /^the "(?P<locator>([^"]*))" HTML field should contain "(?P<html>([^"]*))"$/
When /^(?:|I )fill in the "(?P<field>(?:[^"]|\\")*)" dropdown with "(?P<value>(?:[^"]|\\")*)"$/
- Workaround for chosen.js dropdowns or tree dropdowns which hide the original dropdown field.
When /^(?:|I )fill in "(?P<value>(?:[^"]|\\")*)" for "(?P<field>(?:[^"]|\\")*)" dropdown$/
- Workaround for chosen.js dropdowns or tree dropdowns which hide the original dropdown field.
Given /^I select "([^"]*)" from "([^"]*)" input group$/
- Check an individual input button from a group of inputs
- Example: I select "Admins" from "Groups" input group
(where "Groups" is the title of the CheckboxSetField or OptionsetField form field)
Interactions
Given /^I press the "([^"]*)" button$/
Given /^I click "([^"]*)" in the "([^"]*)" element$/
Given /^I type "([^"]*)" into the dialog$/
Given /^I (?:press|follow) the "([^"]*)" (?:button|link), confirming the dialog$/
Given /^I (?:press|follow) the "([^"]*)" (?:button|link), dismissing the dialog$/
Given /^I confirm the dialog$/
Given /^I dismiss the dialog$/
Login
Given /^I am logged in with "([^"]*)" permissions$/
- Creates a member in a group with the correct permissions.
Given /^I am not logged in$/
When /^I log in with "(?<username>[^"]*)" and "(?<password>[^"]*)"$/
Given /^I should see a log-in form$/
Then /^I will see a "bad" log-in message$/
CMS UI
Then /^I should see an edit page form$/
Then /^I should see the CMS$/
Then /^I should see a "([^"]*)" notice$/
Then /^I should see a "([^"]*)" message$/
Given /^I should see a "([^"]*)" button in CMS Content Toolbar$/
When /^I should see "([^"]*)" in CMS Tree$/
When /^I should not see "([^"]*)" in CMS Tree$/
When /^I expand the "([^"]*)" CMS Panel$/
When /^I click the "([^"]*)" CMS tab$/
Then /^the "([^"]*)" table should contain "([^"]*)"$/
Then /^the "([^"]*)" table should not contain "([^"]*)"$/
Given /^I click on "([^"]*)" in the "([^"]*)" table$/
Then /^I can see the preview panel$/
Given /^the preview contains "([^"]*)"$/
Given /^the preview does not contain "([^"]*)"$/
Fixtures
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)" (:?which )?redirects to (?:(an|a|the) )"(?<targetType>[^"]+)" "(?<targetId>[^"]+)"$/
- Find or create a redirector page and link to another existing page.
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)"$/
- Example: Given a "page" "Page 1"
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)" with (?<data>.*)$/
- Example: Given a "page" "Page 1" with "URL"="page-1" and "Content"="my page 1"
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)" has the following data$/
- Example: And the "page" "Page 2" has the following data
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)" is a (?<relation>[^\s]*) of (?:(an|a|the) )"(?<relationType>[^"]+)" "(?<relationId>[^"]+)"/
- Example: Given the "page" "Page 1.1" is a child of the "page" "Page1"
Given /^(?:(an|a|the) )"(?<type>[^"]+)" "(?<id>[^"]+)" is (?<state>[^"]*)$/
- Example: Given the "page" "Page 1" is not published
Given /^there are the following ([^\s]*) records$/
- Accepts YAML fixture definitions similar to the ones used in SilverStripe unit testing.
Given /^(?:(an|a|the) )"member" "(?<id>[^"]+)" belonging to "(?<groupId>[^"]+)"$/
- Example: Given a "member" "Admin" belonging to "Admin Group"
Given /^(?:(an|a|the) )"member" "(?<id>[^"]+)" belonging to "(?<groupId>[^"]+)" with (?<data>.*)$/
Given /^(?:(an|a|the) )"group" "(?<id>[^"]+)" (?:(with|has)) permissions (?<permissionStr>.*)$/
- Example: Given a "group" "Admin" with permissions "Access to 'Pages' section" and "Access to 'Files' section"
# SilverStripe\Cms\Test\Behaviour\FixtureContext::stepCreateGroupWithPermissions()
Environment
Given /^the current date is "([^"])"$/ Given /^the current time is "([^"])"$/
Transformations
Behat transformations
have the ability to change step arguments based on their original value,
for example to cast any argument matching the \d
regex into an actual PHP integer.
/^(?:(the|a)) time of (?<val>.*)$/
: Transforms relative time statements compatible with strtotime(). Example: "the time of 1 hour ago" might return "22:00:00" if its currently "23:00:00"./^(?:(the|a)) date of (?<val>.*)$/
: Transforms relative date statements compatible with strtotime(). Example: "the date of 2 days ago" might return "2013-10-10" if its currently the 12th of October 2013./^(?:(the|a)) datetime of (?<val>.*)$/
: Transforms relative date and time statements compatible with strtotime(). Example: "the datetime of 2 days ago" might return "2013-10-10 23:00:00" if its currently the 12th of October 2013.