Summary

Options are an important part of any plugin or extension when you need to provide the administrator with the ability to set or choose some variable or alternative in your plugin.

{eac}Doojigger makes it easy to add options to the plugin's administrator settings screen.

• Registering Options
• Option Meta Data
• Option Filters and Actions
• Option Validation

Registering Options

First, when defining options, they must be registered with the base plugin.

For a derivative plugin, this is done with:

$this->registerPluginOptions( {option_group}, {option_meta} );

or

$this->registerNetworkOptions( {option_group}, {option_meta} );

registerPluginOptions() is used for site administrator options while registerNetworkOptions() is used for network (multi-site) administrator options.

For network (multi-site) installations, both may be used; options registered with $this->registerNetworkOptions() are available only on the network admin page; options registered with $this->registerPluginOptions() are available only on the individual site admin page.

You may use $this->get_network_option() or $this->is_network_option() to access network options from the individual sites. On single-site installations, $this->registerNetworkOptions() does nothing. $this->get_network_option() returns null and $this->is_network_option() returns false.

{option_group} is the group name under which the options will appear. {eac}Doojigger uses 'plugin_settings' for site options and 'network_settings' for network options.

{option_group} may also be an array with 2 values. The first being the group name as above, the second being the name of a tab you wish the options to appear on. The default tab is "General".

$this->registerPluginOptions( [ 'plugin_settings' , 'general' ], {option_meta} );

{option_meta} is an array of options to be added/registered (see below).

For a plugin extension, the following methods may be used, using the same format as above.

In the extension's __construct() method, the extension must register itself with the base plugin. In doing so, it can also register options using:

$this->registerExtension( {option_group}, {option_meta} );

Where {option_group} is typically the short class name ($this->className)

If, after registering, the extension needs to add additional options, it can do so using:

$this->registerExtensionOptions( {option_group}, {option_meta} );

This can be done in the __construct(), the initialize(), or the addActionsAndFilters() method.

Optimizing Option Registration

It is rare that plugin or extension options are needed anywhere but within the plugin's administrator settings page. It is both optimal and good practice to register your settings within a test for the page using $this->isSettingsPage()...

if ($this->isSettingsPage())
{
    $this->registerPluginOptions( [ 'plugin_settings' , 'general' ], {option_meta} );
}

Or

if ($this->isSettingsPage())
{
    $this->registerExtension( {option_group}, {option_meta} );
}

New in version 2.0

Another option is to use the just-in-time options_settings_page action that is fired right before rendering the settings html page.

public function __construct(array $header)
{
    if ($this->is_admin())
    {
        $this->add_action( "options_settings_page", array($this, 'admin_settings_page') );
    }
}

public function admin_settings_page()
{
    $this->registerPluginOptions( [ 'plugin_settings' , 'general' ], {option_meta} );
}

Extensions may still register in their constructor, then add options later...

public function __construct(array $header)
{
    if ($this->is_admin())
    {
        $this->registerExtension( ['my_extension', 'my_tab_name'] );
        $this->add_action( "options_settings_page", array($this, 'admin_settings_page') );
    }
}

public function admin_settings_page()
{
    $this->registerExtensionOptions( 'my_extension', {option_meta} );
}

Option Meta Data

The {option_meta} array mentioned above is an array of arrays defining options/settings that can be updated from the plugin's 'settings' page.

• Each option name is automatically prefixed with the plugin name (i.e. 'eacDoojigger' or 'myAwesomePlugin').
• Option names must be unique across the plugin and all extensions.

An option is defined as:

    'my_option_name'   => array(
                'type'          =>  'type: {input type}',
                'label'         =>  'label: {field label}',
                'title'         =>  'title: information text/html to be displayed',
                'before'        =>  'before: text/html to be displayed before field',
                'options'       =>  array({option,...}),
                'default'       =>  'default: {default option or value}',
                'after'         =>  'after: text/html to be displayed after field',
                'info'          =>  'info: Information/instructions',
                'attributes'    =>  html attributes array ['name="value", name="value"'],
                'class'         =>  css class name(s) (added to attributes)
                'style'         =>  css style declaration(s) (added to attributes)
                'encrypt'       =>  true
                'sanitize'      =>  callable function to override internal sanitization
                'filter'        =>  array passed to PHP filter_var [filter_type, options]
        ),

The option array is registered as:

$this->registerPluginOptions( [ 'plugin_settings' , 'general' ],
    [
        $array_of_option
    ]
);

my_option_name screen shot

Option name

The option name may be any valid name passed to the WordPress option methods. If the name is prefixed with '_', '-', or '.' it will not be saved to the database. This is most useful for button or display options.

Option type

The option 'type' value can be any html input type (text, textarea, select, checkbox, radio, etc.). As well as:

• codeedit-js, codeedit-html, codeedit-css, codeedit-php
  • these types invoke the code editor in a textarea field.
• display
  • a custom display field which will translate none-scalable values.
• disabled
  • a disabled text field.
• readonly
  • a disabled text field that can be enabled by double-clicking.
• custom
  • a custom input field defined and processed by your filter code.

Option label

The label value is used as the html <label> value.

Option title

The title value is displayed as a <blockquote> above the field.

Option before

The before value is displayed immediately before the input field.

Option options*

The options value is an list of options and values used in select, checkbox, and radio fields.

Option default

The default value for the option (when the option is not yet set in the wp_options table). May be a single string or an array (for checkbox options).

Option after

The after value is displayed immediately after the input field.

Option info

The info value is displayed as a <cite> below the field.

Option help

The help value is used for field-level contextual hep (if absent, title & info are used).

Option attributes*

The attributes values are passed to the input field as name=value attributes.

Option class

The class value is a string of CSS/DOM class names passed to the input field.

Option style

The style value is a string of CSS style declarations passed to the input field.

Option encrypt

The encrypt option (when truthy) causes the value to be encrypted before being stored in the database. When retrieving the option, use $this->get_option_decrypt(...);

Option sanitize

The sanitize option may be used to override the internal sanitization methods with your own function or to bypass sanitization (if set to false). If the value returned from the sanitize method is different from the value posted, a notification is presented to the user and the value is reverted to the prior value (or null).

Option filter

The filter option uses the PHP filter_var() function and may be used to add an additional filter to sanitize or validate the option value when submitted. To use a custom callback, set filter to: [ FILTER_CALLBACK, ['options'=>'callback_method'] ].

Other Values

width and height may also be set to control the width (columns) of a field and/or the height (rows) of a textarea field.

* option and attributes values may be coded in several formats:

1. as a single string (with multiple attributes)
   • "Option1 Option2" or "Option1='v1' Option2='v2'"
   • "placeholder='First Name'" or "min='0' max='12' step='1'".
2. as an array of strings
   • ["Option1='v1'", "Option2='v2'"]
   • ["placeholder='First Name'"] or ["min='0'", "max='12'", "step='1'"].
3. as a name=>value array
   • ['Option1'=>'v1', 'Option2'=>'v2']
   • ['placeholder'=>'First Name'] or ['min'=>'0', 'max'=>'12', 'step'=>'1'].
4. as an array of arrays
   • [ ['Option1'=>'v1'], ['Option2'=>'v2'] ]
   • [ ['placeholder'=>'First Name'] ] or [ ['min'=>'0'], ['max'=>'12'], ['step'=>'1'] ].

Uses $this->parseAttributes() to parse options and attributes using SimpleXMLElement() to return an associative (name=>value) array; option and attribute strings must be quoted.

See the 'myOptionsTest' plugin included in the 'Extras' folder for a complete example of all input types.

Option Filters and Actions

Two filters are available for all option fields.

1) The first, to modify the definition of the input field (the input html):

The filter name is options_form_input_{option_name}. It takes 4 arguments:

• $html - the current/default html for the field.
• $fieldName - the field/option name.
• $metaData - the option meta data/field definition.
• $currentValue - the current field value (or null).

Your filter must return the html to display the field.

public function form_input_my_option_name($html, $fieldName, $metaData, $currentValue)
{
    $html = "<input ... />";
    return $html;
}
$this->add_filter( 'options_form_input_my_option_name', array($this, 'form_input_my_option_name'), 10, 4 );

2) The second, to process the posted value when submitted:

The filter name is options_form_post_{option_name}. It takes 4 arguments:

• $value - the submitted value of the field.
• $fieldName - the field/option name.
• $metaData - the option meta data/field definition.
• $priorValue - the prior field value (or null).

Your filter must return the value of the field.

public function form_post_my_option_name($value, $fieldName, $metaData, $priorValue)
{
    return $value;
}
$this->add_filter( 'options_form_post_my_option_name', array($this, 'form_post_my_option_name'), 10, 4 );

Notes

• custom input fields must use these filters to define the input html and to validate & sanitize the posted value.
• The second, options_form_post_{option_name} filter is useful for other field types, such as buttons, to perform an action when submitted.
• See also Option Validation (sanitize_option filter)

One action is available when the options form is posted. This action is fired after all posted fields have been processed and updated.

The action name is options_form_post. It takes one argument:

• $postArray - an associative array with the keys being the names of the field/option and the array being the option meta data. Two elements are added to that array:
  • priorValue - the prior field value.
  • postValue - the submitted value of the field.

Actions have no return value.

public function my_options_form_post($postArray)
{
    foreach ($postArray as $fieldName => $metaData)
    {
        if ($metaData['postValue'] != $metaData['priorValue'])
        {
            echo "<p>{$fieldName} has changed from {$metaData['priorValue']} to {$metaData['postValue']}</p>";
        }
    }
}
$this->add_action( 'options_form_post', array($this, 'my_options_form_post') );

Option Validation

When options are saved (posted) from the WordPress administration screen, each value is sanitized and validated (where possible). Checkbox, radio, and select fields have known possible values; values submitted are validated to those known values. Other option values are properly sanitized through WordPress or PHP sanitization helpers according to the option's html input type. Any value that fails sanitization is restored to its previous value. All values are sanitized for safety but may not be validated to specific needs.

It is your responsibility to sanitize and validate any user input values according to WordPress standards and your specific requirements. Do not rely on the browser or JavaScript to validate critical values.

To provide custom validation and sanitization, you may use the aforementioned sanitize option or the options_form_post_{option_name} filter. Both take the same arguments and must return the sanitized value.

public function sanitize_my_option_name($value, $fieldName, $metaData, $priorValue)
{
    // sanitize the value, e.g.
    $value = sanitize_title_with_dashes($value);
    // further validation here
    return $value;
}
$this->add_filter( 'options_form_post_my_option_name', array($this, 'sanitize_my_option_name'), 10, 4 );

Or you may use the sanitization filter that all option values are passed through. Like the options_form_post_{option_name} filter, the sanitize_option filter takes 4 arguments:

• $value - the submitted value of the field.
• $fieldName - the field/option name.
• $metaData - the option meta data/field definition.
• $priorValue - the prior field value (or null).

Your filter must return the value of the field.

public function my_sanitize_option($value, $fieldName, $metaData, $priorValue)
{
    switch ($fieldName)
    {
        case 'my_option_name':
            // sanitize the value, e.g.
            $value = sanitize_title_with_dashes($value);
            // further validation here
            break;
    }
    return $value;
}
$this->add_filter( 'sanitize_option', array($this, 'my_sanitize_option'), 10, 4 );

Use caution with codeedit and custom field types. codeedit fields are passed only through the wp_kses_post function and cannot be further sanitized automatically. custom fields are not processed at all other than by the filter(s) you provide. You must ensure proper use of the submitted values for these field types.

Error Notification

You may use the WordPress add_settings_error() function to notify the user of any validation errors.

add_settings_error( string $setting, string $code, string $message, string $type = 'error' )

Or the convenience methods available for the same purpose:

$this->add_option_error( string $optionName, string $message )
$this->add_option_warning( string $optionName, string $message )
$this->add_option_notice( string $optionName, string $message )
$this->add_option_success( string $optionName, string $message )

These methods use a short-lived transient so that messages may survive a page reload.

Plugins must register any options with:

$this->registerPluginOptions( [ 'plugin_settings' , 'general' ],
    [
        'my_option_name'   => array(
                        'type'          =>  'type: {input type}',
                        'label'         =>  'label: {field label}',
                        'title'         =>  'title: information text/html to be displayed',
                        'options'       =>  array({option,...}),
                        'default'       =>  'default: {default option or value}',
                        'info'          =>  'info: Information/instructions',
                        'attributes'    =>  html attributes array ['name="value", name="value"']
                ),
    ]
);

Plugins may use the options_settings_page action

public function __construct(array $header)
{
    if ($this->is_admin())
    {
        $this->add_action( "options_settings_page", array($this, 'admin_settings_page') );
    }
}

public function admin_settings_page()
{
    $this->registerPluginOptions( [ 'plugin_settings' , 'general' ],
        [
            'my_option_name'   => array(
                            'type'          =>  'type: {input type}',
                            'label'         =>  'label: {field label}',
                            'title'         =>  'title: information text/html to be displayed',
                            'options'       =>  array({option,...}),
                            'default'       =>  'default: {default option or value}',
                            'info'          =>  'info: Information/instructions',
                            'attributes'    =>  html attributes array ['name="value", name="value"']
                    ),
        ]
    );
}

Extensions must register with:

$this->registerExtension( [ $this->className  , 'my_tab_name' ],
    [
        'my_option_name'   => array(
                        'type'          =>  'type: {input type}',
                        'label'         =>  'label: {field label}',
                        'title'         =>  'title: information text/html to be displayed',
                        'options'       =>  array({option,...}),
                        'default'       =>  'default: {default option or value}',
                        'info'          =>  'info: Information/instructions',
                        'attributes'    =>  html attributes array ['name="value", name="value"']
                ),
    ]
);

Extensions may use the options_settings_page action

public function __construct(array $header)
{
    if ($this->is_admin())
    {
        $this->registerExtension( [ $this->className  , 'my_tab_name' ] );
        $this->add_action( "options_settings_page", array($this, 'admin_settings_page') );
    }
}

public function admin_settings_page()
{
    $this->registerExtension( [ $this->className  , 'my_tab_name' ],
        [
            'my_option_name'   => array(
                            'type'          =>  'type: {input type}',
                            'label'         =>  'label: {field label}',
                            'title'         =>  'title: information text/html to be displayed',
                        //  'options'       =>  array({option,...}),
                            'default'       =>  'default: {default option or value}',
                            'info'          =>  'info: Information/instructions',
                        //  'attributes'    =>  html attributes array ['name="value", name="value"']
                    ),
        ]
    );
}

Example (myAwesomePlugin):

/* using pre-defined option fields (from standard_options trait) */
$this->registerPluginOptions('plugin_settings',$this->standard_options(
    [
        'siteEnvironment',
        'adminSettingsMenu',
        'uninstallOptions',
        'backupOptions',
        'restoreOptions'
    ]
));

Example (myAwesomeExtension):

$this->registerExtension( [ $this->className, 'Awesome Examples' ],
    [
        'my_option_name'    => array(
                                'type'          =>  'type: {input type}',
                                'label'         =>  'label: {field label}',
                                'title'         =>  'title: information text/html to be displayed',
                            //  'options'       =>  array({option,...}),
                                'default'       =>  'default: {default option or value}',
                                'info'          =>  'info: Information/instructions',
                            //  'attributes'    =>  html attributes array ['name="value", name="value"']
                            ),
        'my_option_name_a'  => array(
                                'type'          =>  'text',
                                'label'         =>  "Short Label A",
                                'info'          =>  "(text field) Instructions, description, etc."
                            ),
        'my_option_name_b'  => array(
                                'type'          =>  'checkbox',
                                'label'         =>  "Short Label B",
                                'options'       =>  ['single','checkbox','options'],
                                'default'       =>  ['single','checkbox','options'],
                                'info'          =>  "(checkbox field) Instructions, description, etc."
                            ),
        'my_option_name_c'  => array(
                                'type'          =>  'radio',
                                'label'         =>  "Short Label C",
                                'options'       =>  [ ['associated'=>'A'],['radio'=>'R'],['options'=>'O'] ],
                                'default'       =>  'A',
                                'info'          =>  "(radio field) Instructions, description, etc."
                            ),
    ]
);

See the Screen Shots for the output of these 2 examples.

1. My Awesome Plugin with My Awesome Extension