HTMLForm.php

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<?php

class HTMLForm extends ContextSource {
    // A mapping of 'type' inputs onto standard HTMLFormField subclasses
    public static $typeMappings = [
        'api' => 'HTMLApiField',
        'text' => 'HTMLTextField',
        'textwithbutton' => 'HTMLTextFieldWithButton',
        'textarea' => 'HTMLTextAreaField',
        'select' => 'HTMLSelectField',
        'combobox' => 'HTMLComboboxField',
        'radio' => 'HTMLRadioField',
        'multiselect' => 'HTMLMultiSelectField',
        'limitselect' => 'HTMLSelectLimitField',
        'check' => 'HTMLCheckField',
        'toggle' => 'HTMLCheckField',
        'int' => 'HTMLIntField',
        'float' => 'HTMLFloatField',
        'info' => 'HTMLInfoField',
        'selectorother' => 'HTMLSelectOrOtherField',
        'selectandother' => 'HTMLSelectAndOtherField',
        'namespaceselect' => 'HTMLSelectNamespace',
        'namespaceselectwithbutton' => 'HTMLSelectNamespaceWithButton',
        'tagfilter' => 'HTMLTagFilter',
        'submit' => 'HTMLSubmitField',
        'hidden' => 'HTMLHiddenField',
        'edittools' => 'HTMLEditTools',
        'checkmatrix' => 'HTMLCheckMatrix',
        'cloner' => 'HTMLFormFieldCloner',
        'autocompleteselect' => 'HTMLAutoCompleteSelectField',
        // HTMLTextField will output the correct type="" attribute automagically.
        // There are about four zillion other HTML5 input types, like range, but
        // we don't use those at the moment, so no point in adding all of them.
        'email' => 'HTMLTextField',
        'password' => 'HTMLTextField',
        'url' => 'HTMLTextField',
        'title' => 'HTMLTitleTextField',
        'user' => 'HTMLUserTextField',
    ];

    public $mFieldData;

    protected $mMessagePrefix;

    protected $mFlatFields;

    protected $mFieldTree;
    protected $mShowReset = false;
    protected $mShowSubmit = true;
    protected $mSubmitFlags = [ 'constructive', 'primary' ];

    protected $mSubmitCallback;
    protected $mValidationErrorMessage;

    protected $mPre = '';
    protected $mHeader = '';
    protected $mFooter = '';
    protected $mSectionHeaders = [];
    protected $mSectionFooters = [];
    protected $mPost = '';
    protected $mId;
    protected $mName;
    protected $mTableId = '';

    protected $mSubmitID;
    protected $mSubmitName;
    protected $mSubmitText;
    protected $mSubmitTooltip;

    protected $mTitle;
    protected $mMethod = 'post';
    protected $mWasSubmitted = false;

    protected $mAction = false;

    protected $mAutocomplete = false;

    protected $mUseMultipart = false;
    protected $mHiddenFields = [];
    protected $mButtons = [];

    protected $mWrapperLegend = false;

    protected $mTokenSalt = '';

    protected $mSubSectionBeforeFields = true;

    protected $displayFormat = 'table';

    protected $availableDisplayFormats = [
        'table',
        'div',
        'raw',
        'inline',
    ];

    protected $availableSubclassDisplayFormats = [
        'vform',
        'ooui',
    ];

    public static function factory( $displayFormat/*, $arguments...*/ ) {
        $arguments = func_get_args();
        array_shift( $arguments );

        switch ( $displayFormat ) {
            case 'vform':
                $reflector = new ReflectionClass( 'VFormHTMLForm' );
                return $reflector->newInstanceArgs( $arguments );
            case 'ooui':
                $reflector = new ReflectionClass( 'OOUIHTMLForm' );
                return $reflector->newInstanceArgs( $arguments );
            default:
                $reflector = new ReflectionClass( 'HTMLForm' );
                $form = $reflector->newInstanceArgs( $arguments );
                $form->setDisplayFormat( $displayFormat );
                return $form;
        }
    }

    public function __construct( $descriptor, /*IContextSource*/ $context = null,
        $messagePrefix = ''
    ) {
        if ( $context instanceof IContextSource ) {
            $this->setContext( $context );
            $this->mTitle = false; // We don't need them to set a title
            $this->mMessagePrefix = $messagePrefix;
        } elseif ( $context === null && $messagePrefix !== '' ) {
            $this->mMessagePrefix = $messagePrefix;
        } elseif ( is_string( $context ) && $messagePrefix === '' ) {
            // B/C since 1.18
            // it's actually $messagePrefix
            $this->mMessagePrefix = $context;
        }

        // Evil hack for mobile :(
        if (
            !$this->getConfig()->get( 'HTMLFormAllowTableFormat' )
            && $this->displayFormat === 'table'
        ) {
            $this->displayFormat = 'div';
        }

        // Expand out into a tree.
        $loadedDescriptor = [];
        $this->mFlatFields = [];

        foreach ( $descriptor as $fieldname => $info ) {
            $section = isset( $info['section'] )
                ? $info['section']
                : '';

            if ( isset( $info['type'] ) && $info['type'] === 'file' ) {
                $this->mUseMultipart = true;
            }

            $field = static::loadInputFromParameters( $fieldname, $info, $this );

            $setSection =& $loadedDescriptor;
            if ( $section ) {
                $sectionParts = explode( '/', $section );

                while ( count( $sectionParts ) ) {
                    $newName = array_shift( $sectionParts );

                    if ( !isset( $setSection[$newName] ) ) {
                        $setSection[$newName] = [];
                    }

                    $setSection =& $setSection[$newName];
                }
            }

            $setSection[$fieldname] = $field;
            $this->mFlatFields[$fieldname] = $field;
        }

        $this->mFieldTree = $loadedDescriptor;
    }

    public function setDisplayFormat( $format ) {
        if (
            in_array( $format, $this->availableSubclassDisplayFormats, true ) ||
            in_array( $this->displayFormat, $this->availableSubclassDisplayFormats, true )
        ) {
            throw new MWException( 'Cannot change display format after creation, ' .
                'use HTMLForm::factory() instead' );
        }

        if ( !in_array( $format, $this->availableDisplayFormats, true ) ) {
            throw new MWException( 'Display format must be one of ' .
                print_r( $this->availableDisplayFormats, true ) );
        }

        // Evil hack for mobile :(
        if ( !$this->getConfig()->get( 'HTMLFormAllowTableFormat' ) && $format === 'table' ) {
            $format = 'div';
        }

        $this->displayFormat = $format;

        return $this;
    }

    public function getDisplayFormat() {
        return $this->displayFormat;
    }

    public function isVForm() {
        wfDeprecated( __METHOD__, '1.25' );
        return false;
    }

    public static function getClassFromDescriptor( $fieldname, &$descriptor ) {
        if ( isset( $descriptor['class'] ) ) {
            $class = $descriptor['class'];
        } elseif ( isset( $descriptor['type'] ) ) {
            $class = static::$typeMappings[$descriptor['type']];
            $descriptor['class'] = $class;
        } else {
            $class = null;
        }

        if ( !$class ) {
            throw new MWException( "Descriptor with no class for $fieldname: "
                . print_r( $descriptor, true ) );
        }

        return $class;
    }

    public static function loadInputFromParameters( $fieldname, $descriptor,
        HTMLForm $parent = null
    ) {
        $class = static::getClassFromDescriptor( $fieldname, $descriptor );

        $descriptor['fieldname'] = $fieldname;
        if ( $parent ) {
            $descriptor['parent'] = $parent;
        }

        # @todo This will throw a fatal error whenever someone try to use
        # 'class' to feed a CSS class instead of 'cssclass'. Would be
        # great to avoid the fatal error and show a nice error.
        return new $class( $descriptor );
    }

    public function prepareForm() {
        # Check if we have the info we need
        if ( !$this->mTitle instanceof Title && $this->mTitle !== false ) {
            throw new MWException( 'You must call setTitle() on an HTMLForm' );
        }

        # Load data from the request.
        $this->loadData();

        return $this;
    }

    public function tryAuthorizedSubmit() {
        $result = false;

        $submit = false;
        if ( $this->getMethod() !== 'post' ) {
            $submit = true; // no session check needed
        } elseif ( $this->getRequest()->wasPosted() ) {
            $editToken = $this->getRequest()->getVal( 'wpEditToken' );
            if ( $this->getUser()->isLoggedIn() || $editToken !== null ) {
                // Session tokens for logged-out users have no security value.
                // However, if the user gave one, check it in order to give a nice
                // "session expired" error instead of "permission denied" or such.
                $submit = $this->getUser()->matchEditToken( $editToken, $this->mTokenSalt );
            } else {
                $submit = true;
            }
        }

        if ( $submit ) {
            $this->mWasSubmitted = true;
            $result = $this->trySubmit();
        }

        return $result;
    }

    public function show() {
        $this->prepareForm();

        $result = $this->tryAuthorizedSubmit();
        if ( $result === true || ( $result instanceof Status && $result->isGood() ) ) {
            return $result;
        }

        $this->displayForm( $result );

        return false;
    }

    public function showAlways() {
        $this->prepareForm();

        $result = $this->tryAuthorizedSubmit();

        $this->displayForm( $result );

        return $result;
    }

    public function trySubmit() {
        $valid = true;
        $hoistedErrors = [];
        $hoistedErrors[] = isset( $this->mValidationErrorMessage )
            ? $this->mValidationErrorMessage
            : [ 'htmlform-invalid-input' ];

        $this->mWasSubmitted = true;

        # Check for cancelled submission
        foreach ( $this->mFlatFields as $fieldname => $field ) {
            if ( !array_key_exists( $fieldname, $this->mFieldData ) ) {
                continue;
            }
            if ( $field->cancelSubmit( $this->mFieldData[$fieldname], $this->mFieldData ) ) {
                $this->mWasSubmitted = false;
                return false;
            }
        }

        # Check for validation
        foreach ( $this->mFlatFields as $fieldname => $field ) {
            if ( !array_key_exists( $fieldname, $this->mFieldData ) ) {
                continue;
            }
            if ( $field->isHidden( $this->mFieldData ) ) {
                continue;
            }
            $res = $field->validate( $this->mFieldData[$fieldname], $this->mFieldData );
            if ( $res !== true ) {
                $valid = false;
                if ( $res !== false && !$field->canDisplayErrors() ) {
                    $hoistedErrors[] = [ 'rawmessage', $res ];
                }
            }
        }

        if ( !$valid ) {
            if ( count( $hoistedErrors ) === 1 ) {
                $hoistedErrors = $hoistedErrors[0];
            }
            return $hoistedErrors;
        }

        $callback = $this->mSubmitCallback;
        if ( !is_callable( $callback ) ) {
            throw new MWException( 'HTMLForm: no submit callback provided. Use ' .
                'setSubmitCallback() to set one.' );
        }

        $data = $this->filterDataForSubmit( $this->mFieldData );

        $res = call_user_func( $callback, $data, $this );
        if ( $res === false ) {
            $this->mWasSubmitted = false;
        }

        return $res;
    }

    public function wasSubmitted() {
        return $this->mWasSubmitted;
    }

    public function setSubmitCallback( $cb ) {
        $this->mSubmitCallback = $cb;

        return $this;
    }

    public function setValidationErrorMessage( $msg ) {
        $this->mValidationErrorMessage = $msg;

        return $this;
    }

    public function setIntro( $msg ) {
        $this->setPreText( $msg );

        return $this;
    }

    public function setPreText( $msg ) {
        $this->mPre = $msg;

        return $this;
    }

    public function addPreText( $msg ) {
        $this->mPre .= $msg;

        return $this;
    }

    public function addHeaderText( $msg, $section = null ) {
        if ( $section === null ) {
            $this->mHeader .= $msg;
        } else {
            if ( !isset( $this->mSectionHeaders[$section] ) ) {
                $this->mSectionHeaders[$section] = '';
            }
            $this->mSectionHeaders[$section] .= $msg;
        }

        return $this;
    }

    public function setHeaderText( $msg, $section = null ) {
        if ( $section === null ) {
            $this->mHeader = $msg;
        } else {
            $this->mSectionHeaders[$section] = $msg;
        }

        return $this;
    }

    public function getHeaderText( $section = null ) {
        if ( $section === null ) {
            return $this->mHeader;
        } else {
            return isset( $this->mSectionHeaders[$section] ) ? $this->mSectionHeaders[$section] : '';
        }
    }

    public function addFooterText( $msg, $section = null ) {
        if ( $section === null ) {
            $this->mFooter .= $msg;
        } else {
            if ( !isset( $this->mSectionFooters[$section] ) ) {
                $this->mSectionFooters[$section] = '';
            }
            $this->mSectionFooters[$section] .= $msg;
        }

        return $this;
    }

    public function setFooterText( $msg, $section = null ) {
        if ( $section === null ) {
            $this->mFooter = $msg;
        } else {
            $this->mSectionFooters[$section] = $msg;
        }

        return $this;
    }

    public function getFooterText( $section = null ) {
        if ( $section === null ) {
            return $this->mFooter;
        } else {
            return isset( $this->mSectionFooters[$section] ) ? $this->mSectionFooters[$section] : '';
        }
    }

    public function addPostText( $msg ) {
        $this->mPost .= $msg;

        return $this;
    }

    public function setPostText( $msg ) {
        $this->mPost = $msg;

        return $this;
    }

    public function addHiddenField( $name, $value, array $attribs = [] ) {
        $attribs += [ 'name' => $name ];
        $this->mHiddenFields[] = [ $value, $attribs ];

        return $this;
    }

    public function addHiddenFields( array $fields ) {
        foreach ( $fields as $name => $value ) {
            $this->mHiddenFields[] = [ $value, [ 'name' => $name ] ];
        }

        return $this;
    }

    public function addButton( $data ) {
        if ( !is_array( $data ) ) {
            $args = func_get_args();
            if ( count( $args ) < 2 || count( $args ) > 4 ) {
                throw new InvalidArgumentException(
                    'Incorrect number of arguments for deprecated calling style'
                );
            }
            $data = [
                'name' => $args[0],
                'value' => $args[1],
                'id' => isset( $args[2] ) ? $args[2] : null,
                'attribs' => isset( $args[3] ) ? $args[3] : null,
            ];
        } else {
            if ( !isset( $data['name'] ) ) {
                throw new InvalidArgumentException( 'A name is required' );
            }
            if ( !isset( $data['value'] ) ) {
                throw new InvalidArgumentException( 'A value is required' );
            }
        }
        $this->mButtons[] = $data + [
            'id' => null,
            'attribs' => null,
            'flags' => null,
        ];

        return $this;
    }

    public function setTokenSalt( $salt ) {
        $this->mTokenSalt = $salt;

        return $this;
    }

    public function displayForm( $submitResult ) {
        $this->getOutput()->addHTML( $this->getHTML( $submitResult ) );
    }

    public function getHTML( $submitResult ) {
        # For good measure (it is the default)
        $this->getOutput()->preventClickjacking();
        $this->getOutput()->addModules( 'mediawiki.htmlform' );
        $this->getOutput()->addModuleStyles( 'mediawiki.htmlform.styles' );

        $html = ''
            . $this->getErrors( $submitResult )
            . $this->getHeaderText()
            . $this->getBody()
            . $this->getHiddenFields()
            . $this->getButtons()
            . $this->getFooterText();

        $html = $this->wrapForm( $html );

        return '' . $this->mPre . $html . $this->mPost;
    }

    protected function getFormAttributes() {
        # Use multipart/form-data
        $encType = $this->mUseMultipart
            ? 'multipart/form-data'
            : 'application/x-www-form-urlencoded';
        # Attributes
        $attribs = [
            'action' => $this->getAction(),
            'method' => $this->getMethod(),
            'enctype' => $encType,
        ];
        if ( $this->mId ) {
            $attribs['id'] = $this->mId;
        }
        if ( $this->mAutocomplete ) {
            $attribs['autocomplete'] = $this->mAutocomplete;
        }
        if ( $this->mName ) {
            $attribs['name'] = $this->mName;
        }
        return $attribs;
    }

    public function wrapForm( $html ) {
        # Include a <fieldset> wrapper for style, if requested.
        if ( $this->mWrapperLegend !== false ) {
            $legend = is_string( $this->mWrapperLegend ) ? $this->mWrapperLegend : false;
            $html = Xml::fieldset( $legend, $html );
        }

        return Html::rawElement(
            'form',
            $this->getFormAttributes() + [ 'class' => 'visualClear' ],
            $html
        );
    }

    public function getHiddenFields() {
        $html = '';
        if ( $this->getMethod() === 'post' ) {
            $html .= Html::hidden(
                'wpEditToken',
                $this->getUser()->getEditToken( $this->mTokenSalt ),
                [ 'id' => 'wpEditToken' ]
            ) . "\n";
            $html .= Html::hidden( 'title', $this->getTitle()->getPrefixedText() ) . "\n";
        }

        $articlePath = $this->getConfig()->get( 'ArticlePath' );
        if ( strpos( $articlePath, '?' ) !== false && $this->getMethod() === 'get' ) {
            $html .= Html::hidden( 'title', $this->getTitle()->getPrefixedText() ) . "\n";
        }

        foreach ( $this->mHiddenFields as $data ) {
            list( $value, $attribs ) = $data;
            $html .= Html::hidden( $attribs['name'], $value, $attribs ) . "\n";
        }

        return $html;
    }

    public function getButtons() {
        $buttons = '';
        $useMediaWikiUIEverywhere = $this->getConfig()->get( 'UseMediaWikiUIEverywhere' );

        if ( $this->mShowSubmit ) {
            $attribs = [];

            if ( isset( $this->mSubmitID ) ) {
                $attribs['id'] = $this->mSubmitID;
            }

            if ( isset( $this->mSubmitName ) ) {
                $attribs['name'] = $this->mSubmitName;
            }

            if ( isset( $this->mSubmitTooltip ) ) {
                $attribs += Linker::tooltipAndAccesskeyAttribs( $this->mSubmitTooltip );
            }

            $attribs['class'] = [ 'mw-htmlform-submit' ];

            if ( $useMediaWikiUIEverywhere ) {
                foreach ( $this->mSubmitFlags as $flag ) {
                    $attribs['class'][] = 'mw-ui-' . $flag;
                }
                $attribs['class'][] = 'mw-ui-button';
            }

            $buttons .= Xml::submitButton( $this->getSubmitText(), $attribs ) . "\n";
        }

        if ( $this->mShowReset ) {
            $buttons .= Html::element(
                'input',
                [
                    'type' => 'reset',
                    'value' => $this->msg( 'htmlform-reset' )->text(),
                    'class' => $useMediaWikiUIEverywhere ? 'mw-ui-button' : null,
                ]
            ) . "\n";
        }

        // IE<8 has bugs with <button>, so we'll need to avoid them.
        $isBadIE = preg_match( '/MSIE [1-7]\./i', $this->getRequest()->getHeader( 'User-Agent' ) );

        foreach ( $this->mButtons as $button ) {
            $attrs = [
                'type' => 'submit',
                'name' => $button['name'],
                'value' => $button['value']
            ];

            if ( isset( $button['label-message'] ) ) {
                $label = $this->getMessage( $button['label-message'] )->parse();
            } elseif ( isset( $button['label'] ) ) {
                $label = htmlspecialchars( $button['label'] );
            } elseif ( isset( $button['label-raw'] ) ) {
                $label = $button['label-raw'];
            } else {
                $label = htmlspecialchars( $button['value'] );
            }

            if ( $button['attribs'] ) {
                $attrs += $button['attribs'];
            }

            if ( isset( $button['id'] ) ) {
                $attrs['id'] = $button['id'];
            }

            if ( $useMediaWikiUIEverywhere ) {
                $attrs['class'] = isset( $attrs['class'] ) ? (array)$attrs['class'] : [];
                $attrs['class'][] = 'mw-ui-button';
            }

            if ( $isBadIE ) {
                $buttons .= Html::element( 'input', $attrs ) . "\n";
            } else {
                $buttons .= Html::rawElement( 'button', $attrs, $label ) . "\n";
            }
        }

        if ( !$buttons ) {
            return '';
        }

        return Html::rawElement( 'span',
            [ 'class' => 'mw-htmlform-submit-buttons' ], "\n$buttons" ) . "\n";
    }

    public function getBody() {
        return $this->displaySection( $this->mFieldTree, $this->mTableId );
    }

    public function getErrors( $errors ) {
        if ( $errors instanceof Status ) {
            if ( $errors->isOK() ) {
                $errorstr = '';
            } else {
                $errorstr = $this->getOutput()->parse( $errors->getWikiText() );
            }
        } elseif ( is_array( $errors ) ) {
            $errorstr = $this->formatErrors( $errors );
        } else {
            $errorstr = $errors;
        }

        return $errorstr
            ? Html::rawElement( 'div', [ 'class' => 'error' ], $errorstr )
            : '';
    }

    public function formatErrors( $errors ) {
        $errorstr = '';

        foreach ( $errors as $error ) {
            $errorstr .= Html::rawElement(
                'li',
                [],
                $this->getMessage( $error )->parse()
            );
        }

        $errorstr = Html::rawElement( 'ul', [], $errorstr );

        return $errorstr;
    }

    public function setSubmitText( $t ) {
        $this->mSubmitText = $t;

        return $this;
    }

    public function setSubmitDestructive() {
        $this->mSubmitFlags = [ 'destructive', 'primary' ];
    }

    public function setSubmitProgressive() {
        $this->mSubmitFlags = [ 'progressive', 'primary' ];
    }

    public function setSubmitTextMsg( $msg ) {
        if ( !$msg instanceof Message ) {
            $msg = $this->msg( $msg );
        }
        $this->setSubmitText( $msg->text() );

        return $this;
    }

    public function getSubmitText() {
        return $this->mSubmitText ?: $this->msg( 'htmlform-submit' )->text();
    }

    public function setSubmitName( $name ) {
        $this->mSubmitName = $name;

        return $this;
    }

    public function setSubmitTooltip( $name ) {
        $this->mSubmitTooltip = $name;

        return $this;
    }

    public function setSubmitID( $t ) {
        $this->mSubmitID = $t;

        return $this;
    }

    public function suppressDefaultSubmit( $suppressSubmit = true ) {
        $this->mShowSubmit = !$suppressSubmit;

        return $this;
    }

    public function setTableId( $id ) {
        $this->mTableId = $id;

        return $this;
    }

    public function setId( $id ) {
        $this->mId = $id;

        return $this;
    }

    public function setName( $name ) {
        $this->mName = $name;

        return $this;
    }

    public function setWrapperLegend( $legend ) {
        $this->mWrapperLegend = $legend;

        return $this;
    }

    public function setWrapperLegendMsg( $msg ) {
        if ( !$msg instanceof Message ) {
            $msg = $this->msg( $msg );
        }
        $this->setWrapperLegend( $msg->text() );

        return $this;
    }

    public function setMessagePrefix( $p ) {
        $this->mMessagePrefix = $p;

        return $this;
    }

    public function setTitle( $t ) {
        $this->mTitle = $t;

        return $this;
    }

    public function getTitle() {
        return $this->mTitle === false
            ? $this->getContext()->getTitle()
            : $this->mTitle;
    }

    public function setMethod( $method = 'post' ) {
        $this->mMethod = strtolower( $method );

        return $this;
    }

    public function getMethod() {
        return $this->mMethod;
    }

    protected function wrapFieldSetSection( $legend, $section, $attributes ) {
        return Xml::fieldset( $legend, $section, $attributes ) . "\n";
    }

    public function displaySection( $fields,
        $sectionName = '',
        $fieldsetIDPrefix = '',
        &$hasUserVisibleFields = false
    ) {
        if ( $this->mFieldData === null ) {
            throw new LogicException( 'HTMLForm::displaySection() called on uninitialized field data. '
                . 'You probably called displayForm() without calling prepareForm() first.' );
        }

        $displayFormat = $this->getDisplayFormat();

        $html = [];
        $subsectionHtml = '';
        $hasLabel = false;

        // Conveniently, PHP method names are case-insensitive.
        // For grep: this can call getDiv, getRaw, getInline, getVForm, getOOUI
        $getFieldHtmlMethod = $displayFormat === 'table' ? 'getTableRow' : ( 'get' . $displayFormat );

        foreach ( $fields as $key => $value ) {
            if ( $value instanceof HTMLFormField ) {
                $v = array_key_exists( $key, $this->mFieldData )
                    ? $this->mFieldData[$key]
                    : $value->getDefault();

                $retval = $value->$getFieldHtmlMethod( $v );

                // check, if the form field should be added to
                // the output.
                if ( $value->hasVisibleOutput() ) {
                    $html[] = $retval;

                    $labelValue = trim( $value->getLabel() );
                    if ( $labelValue !== '&#160;' && $labelValue !== '' ) {
                        $hasLabel = true;
                    }

                    $hasUserVisibleFields = true;
                }
            } elseif ( is_array( $value ) ) {
                $subsectionHasVisibleFields = false;
                $section =
                    $this->displaySection( $value,
                        "mw-htmlform-$key",
                        "$fieldsetIDPrefix$key-",
                        $subsectionHasVisibleFields );
                $legend = null;

                if ( $subsectionHasVisibleFields === true ) {
                    // Display the section with various niceties.
                    $hasUserVisibleFields = true;

                    $legend = $this->getLegend( $key );

                    $section = $this->getHeaderText( $key ) .
                        $section .
                        $this->getFooterText( $key );

                    $attributes = [];
                    if ( $fieldsetIDPrefix ) {
                        $attributes['id'] = Sanitizer::escapeId( "$fieldsetIDPrefix$key" );
                    }
                    $subsectionHtml .= $this->wrapFieldSetSection( $legend, $section, $attributes );
                } else {
                    // Just return the inputs, nothing fancy.
                    $subsectionHtml .= $section;
                }
            }
        }

        $html = $this->formatSection( $html, $sectionName, $hasLabel );

        if ( $subsectionHtml ) {
            if ( $this->mSubSectionBeforeFields ) {
                return $subsectionHtml . "\n" . $html;
            } else {
                return $html . "\n" . $subsectionHtml;
            }
        } else {
            return $html;
        }
    }

    protected function formatSection( array $fieldsHtml, $sectionName, $anyFieldHasLabel ) {
        $displayFormat = $this->getDisplayFormat();
        $html = implode( '', $fieldsHtml );

        if ( $displayFormat === 'raw' ) {
            return $html;
        }

        $classes = [];

        if ( !$anyFieldHasLabel ) { // Avoid strange spacing when no labels exist
            $classes[] = 'mw-htmlform-nolabel';
        }

        $attribs = [
            'class' => implode( ' ', $classes ),
        ];

        if ( $sectionName ) {
            $attribs['id'] = Sanitizer::escapeId( $sectionName );
        }

        if ( $displayFormat === 'table' ) {
            return Html::rawElement( 'table',
                    $attribs,
                    Html::rawElement( 'tbody', [], "\n$html\n" ) ) . "\n";
        } elseif ( $displayFormat === 'inline' ) {
            return Html::rawElement( 'span', $attribs, "\n$html\n" );
        } else {
            return Html::rawElement( 'div', $attribs, "\n$html\n" );
        }
    }

    public function loadData() {
        $fieldData = [];

        foreach ( $this->mFlatFields as $fieldname => $field ) {
            $request = $this->getRequest();
            if ( $field->skipLoadData( $request ) ) {
                continue;
            } elseif ( !empty( $field->mParams['disabled'] ) ) {
                $fieldData[$fieldname] = $field->getDefault();
            } else {
                $fieldData[$fieldname] = $field->loadDataFromRequest( $request );
            }
        }

        # Filter data.
        foreach ( $fieldData as $name => &$value ) {
            $field = $this->mFlatFields[$name];
            $value = $field->filter( $value, $this->mFlatFields );
        }

        $this->mFieldData = $fieldData;
    }

    public function suppressReset( $suppressReset = true ) {
        $this->mShowReset = !$suppressReset;

        return $this;
    }

    public function filterDataForSubmit( $data ) {
        return $data;
    }

    public function getLegend( $key ) {
        return $this->msg( "{$this->mMessagePrefix}-$key" )->text();
    }

    public function setAction( $action ) {
        $this->mAction = $action;

        return $this;
    }

    public function getAction() {
        // If an action is alredy provided, return it
        if ( $this->mAction !== false ) {
            return $this->mAction;
        }

        $articlePath = $this->getConfig()->get( 'ArticlePath' );
        // Check whether we are in GET mode and the ArticlePath contains a "?"
        // meaning that getLocalURL() would return something like "index.php?title=...".
        // As browser remove the query string before submitting GET forms,
        // it means that the title would be lost. In such case use wfScript() instead
        // and put title in an hidden field (see getHiddenFields()).
        if ( strpos( $articlePath, '?' ) !== false && $this->getMethod() === 'get' ) {
            return wfScript();
        }

        return $this->getTitle()->getLocalURL();
    }

    public function setAutocomplete( $autocomplete ) {
        $this->mAutocomplete = $autocomplete;

        return $this;
    }

    protected function getMessage( $value ) {
        return Message::newFromSpecifier( $value )->setContext( $this );
    }
}