# Class YiiRequirementChecker

Inheritance | YiiRequirementChecker
Available since version | 2.0
Source Code | https://github.com/yiisoft/yii2/blob/master/framework/equirementChecker.php

YiiRequirementChecker allows checking, if current system meets the requirements for running the Yii application.

This class allows rendering of the check report for the web and console application interface.

Example:

    require_once 'path/to/YiiRequirementChecker.php';
    $requirementsChecker = new YiiRequirementChecker();
    $requirements = array(
        array(
            'name' => 'PHP Some Extension',
            'mandatory' => true,
            'condition' => extension_loaded('some_extension'),
            'by' => 'Some application feature',
            'memo' => 'PHP extension "some_extension" required',
        ),
    );
    $requirementsChecker->checkYii()->check($requirements)->render();

If you wish to render the report with your own representation, use getResult() instead of render()

Requirement condition could be in format "eval:PHP expression". In this case specified PHP expression will be evaluated in the context of this class instance. For example:

    $requirements = array(
        array(
            'name' => 'Upload max file size',
            'condition' => 'eval:$this->checkUploadMaxFileSize("5M")',
        ),
    );

Note: this class definition does not match ordinary Yii style, because it should match PHP 4.3 and should not use features from newer PHP versions!

## Public Properties

Hide inherited properties

Property | Type | Description | Defined By
--- | --- | --- | ---
$result | array|null | the check results, this property is for internal usage only. | YiiRequirementChecker

## Public Methods

Hide inherited methods

Method | Description | Defined By
--- | --- | ---
check() | Check the given requirements, collecting results into internal field. | YiiRequirementChecker
checkPhpExtensionVersion() | Checks if the given PHP extension is available and its version matches the given one. | YiiRequirementChecker
checkPhpIniOff() | Checks if PHP configuration option (from php.ini) is off. | YiiRequirementChecker
checkPhpIniOn() | Checks if PHP configuration option (from php.ini) is on. | YiiRequirementChecker
checkUploadMaxFileSize() | Checks if upload max file size matches the given range. | YiiRequirementChecker
checkYii() | Performs the check for the Yii core requirements. | YiiRequirementChecker
compareByteSize() | Compare byte sizes of values given in the verbose representation, like '5M', '15K' etc. | YiiRequirementChecker
evaluateExpression() | Evaluates a PHP expression under the context of this class. | YiiRequirementChecker
getByteSize() | Gets the size in bytes from verbose size representation. | YiiRequirementChecker
getNowDate() | Returns the now date if possible in string representation. | YiiRequirementChecker
getResult() | Return the check results. | YiiRequirementChecker
getServerInfo() | Returns the server information. | YiiRequirementChecker
normalizeRequirement() | Normalizes requirement ensuring it has correct format. | YiiRequirementChecker
render() | Renders the requirements check result. | YiiRequirementChecker
renderViewFile() | Renders a view file. | YiiRequirementChecker
usageError() | Displays a usage error. | YiiRequirementChecker

## Property Details

$result public property

the check results, this property is for internal usage only.

public array|null $result = null

## Method Details

check() public method

Check the given requirements, collecting results into internal field.

This method can be invoked several times checking different requirement sets. Use getResult() or render() to get the results.

public $this check ( $requirements )
$requirements | array|string | Requirements to be checked. If an array, it is treated as the set of requirements; If a string, it is treated as the path of the file, which contains the requirements;
return | $this | Self instance.

checkPhpExtensionVersion() public method

Checks if the given PHP extension is available and its version matches the given one.

public boolean checkPhpExtensionVersion ( $extensionName, $version, $compare = '>=' )
$extensionName | string | PHP extension name.
$version | string | Required PHP extension version.
$compare | string | Comparison operator, by default '>='
return | boolean | If PHP extension version matches.

checkPhpIniOff() public method

Checks if PHP configuration option (from php.ini) is off.

public boolean checkPhpIniOff ( $name )
$name | string | Configuration option name.
return | boolean | Option is off.

checkPhpIniOn() public method

Checks if PHP configuration option (from php.ini) is on.

public boolean checkPhpIniOn ( $name )
$name | string | Configuration option name.
return | boolean | Option is on.

checkUploadMaxFileSize() public method

Checks if upload max file size matches the given range.

public boolean checkUploadMaxFileSize ( $min = null, $max = null )
$min | string|null | Verbose file size minimum required value, pass null to skip minimum check.
$max | string|null | Verbose file size maximum required value, pass null to skip maximum check.
return | boolean | Success.

checkYii() public method

Performs the check for the Yii core requirements.

public YiiRequirementChecker checkYii ( )
return | YiiRequirementChecker | Self instance.

compareByteSize() public method

Compare byte sizes of values given in the verbose representation, like '5M', '15K' etc.

public boolean compareByteSize ( $a, $b, $compare = '>=' )
$a | string | First value.
$b | string | Second value.
$compare | string | Comparison operator, by default '>='.
return | boolean | Comparison result.

evaluateExpression() public method

Evaluates a PHP expression under the context of this class.

public mixed evaluateExpression ( $expression )
$expression | string | A PHP expression to be evaluated.
return | mixed | The expression result.

getByteSize() public method

Gets the size in bytes from verbose size representation.

For example: '5K' => 5*1024

public integer getByteSize ( $verboseSize )
$verboseSize | string | Verbose size representation.
return | integer | Actual size in bytes.

getNowDate() public method

Returns the now date if possible in string representation.

public string getNowDate ( )
return | string | Now date.

getResult() public method

Return the check results.

public array|null getResult ( )
return | array|null | Check results in format:
    array(
        'summary' => array(
            'total' => total number of checks,
            'errors' => number of errors,
            'warnings' => number of warnings,
        ),
        'requirements' => array(
            array(
                ...
                'error' => is there an error,
                'warning' => is there a warning,
            ),
            ...
        ),
    )

getServerInfo() public method

Returns the server information.

public string getServerInfo ( )
return | string | Server information.

normalizeRequirement() public method

Normalizes requirement ensuring it has correct format.

public array normalizeRequirement ( $requirement, $requirementKey = 0 )
$requirement | array | Raw requirement.
$requirementKey | integer | Requirement key in the list.
return | array | Normalized requirement.

render() public method

Renders the requirements check result.

The output will vary depending is a script running from web or from console.

public void render ( )

renderViewFile() public method

Renders a view file.

This method includes the view file as a PHP script and captures the display result if required.

public string renderViewFile ( $_viewFile_, $_data_ = null, $_return_ = false )
$_viewFile_ | string | View file
$_data_ | array | Data to be extracted and made available to the view file
$_return_ | boolean | Whether the rendering result should be returned as a string
return | string | The rendering result. Null if the rendering result is not required.

usageError() public method

Displays a usage error.

This method will then terminate the execution of the current application.

public void usageError ( $message )
$message | string | The error message