# Object Construction¶

In phpspec specs the object you are describing is not a separate variable but is $this. So instead of writing something like: <?php namespace spec; use PhpSpec\ObjectBehavior; class MarkdownSpec extends ObjectBehavior { function it_converts_plain_text_to_html_paragraphs() {$markdown = new Markdown();
$markdown->toHtml("Hi, there")->shouldReturn("<p>Hi, there</p>"); } }  as you might with other tools, you write: <?php namespace spec; use PhpSpec\ObjectBehavior; class MarkdownSpec extends ObjectBehavior { function it_converts_plain_text_to_html_paragraphs() {$this->toHtml("Hi, there")->shouldReturn("<p>Hi, there</p>");
}
}


On consequence this means that you do not construct the object you are describing in the examples. Instead phpspec handles the creation of the object you are describing when you run the specs.

The default way phpspec does this is the same as new Markdown(). If it does not need any values or dependencies to be passed to it then this is fine but for many objects this will not be good enough. You can tell phpspec how you want it to create the object though.

## Using the Constructor¶

You can tell phpspec to pass values to the constructor when it constructs the object:

<?php

namespace spec;

use PhpSpec\ObjectBehavior;
use Markdown\Writer;

class MarkdownSpec extends ObjectBehavior
{
function it_outputs_converted_text(Writer $writer) {$this->beConstructedWith($writer);$writer->writeText("<p>Hi, there</p>")->shouldBeCalled();

$this->outputHtml("Hi, there"); } }  ## Using a Factory Method¶ You may not want to use the constructor but use static factory methods to create the class. This allows you to create it in different ways for different use cases since you can only have a single constructor in PHP. <?php use Markdown\Writer; class Markdown { public static function createForWriting(Writer$writer)
{
$markdown = new Self();$markdown->writer = $writer; return$markdown;
}
}


You can tell phpspec this is how you want to construct the object as follows:

<?php

namespace spec;

use PhpSpec\ObjectBehavior;
use Markdown\Writer;

class MarkdownSpec extends ObjectBehavior
{
function it_outputs_converted_text(Writer $writer) {$this->beConstructedThrough('createForWriting', [$writer]);$writer->writeText("<p>Hi, there</p>")->shouldBeCalled();

$this->outputHtml("Hi, there"); } }  Where the first argument is the method name and the second an array of the values to pass to that method. To be more descriptive, shorter syntaxes are available. All of the following are equivalent: $this->beConstructedNamed('Bob');
$this->beConstructedThroughNamed('Bob');$this->beConstructedThrough('Named', array('Bob'));


## Overriding¶

To avoid repetition you can tell phpspec how to construct the object in let. However, you may have a single example that needs constructing in a different way. You can do this by calling beConstructedWith again in the example. The last time you call beConstructedWith will determine how phpspec constructs the object:

<?php

namespace spec;

use PhpSpec\ObjectBehavior;
use Markdown\Writer;

class MarkdownSpec extends ObjectBehavior
{
function let(Writer $writer) {$this->beConstructedWith($writer, true); } function it_outputs_converted_text(Writer$writer)
{
// constructed with second argument set to true
// ...
}

function it_does_something_if_argument_is_false(Writer $writer) {$this->beConstructedWith(\$writer, false);
// constructed with second argument set to false
// ...
}
}