nextcloud/resources/app-info.xsd

<?xml version="1.0"?>
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
           elementFormDefault="qualified" attributeFormDefault="unqualified">

    <xs:element name="info">
        <xs:complexType>
            <xs:sequence>
                <xs:element name="id" type="id" minOccurs="1" maxOccurs="1"/>
                <xs:element name="name" type="l10n-string" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="summary" type="l10n-string" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="description" type="l10n-text" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="version" type="semver"
                            minOccurs="1" maxOccurs="1"/>
                <xs:element name="licence" type="licence" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="author" type="author" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="namespace" type="limited-string"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="types" type="types" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="documentation" type="documentation"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="category" type="category" minOccurs="1"
                            maxOccurs="unbounded"/>
                <xs:element name="website" type="url" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="discussion" type="url" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="bugs" type="url" minOccurs="1"
                            maxOccurs="1"/>
                <xs:element name="repository" type="repository" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="screenshot" type="screenshot" minOccurs="0"
                            maxOccurs="10"/>
                <xs:element name="dependencies" type="dependencies"
                            minOccurs="1" maxOccurs="1"/>
                <xs:element name="background-jobs" type="jobs"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="repair-steps" type="repair-steps"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="two-factor-providers"
                            type="two-factor-providers"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="commands" type="commands"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="settings" type="settings" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="activity" type="activity" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="dashboard" type="dashboard"
                            minOccurs="0" maxOccurs="1"/>
                <xs:element name="navigations" type="navigations" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="contactsmenu" type="contactsmenu" minOccurs="0"
                            maxOccurs="1"/>
                <xs:element name="collaboration" type="collaboration" minOccurs="0"
                            maxOccurs="1" />
                <xs:element name="sabre" type="sabre" minOccurs="0"
                            maxOccurs="1" />
                <xs:element name="trash" type="trash" minOccurs="0"
                            maxOccurs="1" />
            </xs:sequence>
        </xs:complexType>
        <xs:unique name="uniqueNameL10n">
            <xs:selector xpath="name"/>
            <xs:field xpath="@lang"/>
        </xs:unique>
        <xs:unique name="uniqueSummaryL10n">
            <xs:selector xpath="summary"/>
            <xs:field xpath="@lang"/>
        </xs:unique>
        <xs:unique name="uniqueDescriptionL10n">
            <xs:selector xpath="description"/>
            <xs:field xpath="@lang"/>
        </xs:unique>
        <xs:unique name="uniqueLicense">
            <xs:selector xpath="licence"/>
            <xs:field xpath="."/>
        </xs:unique>
        <xs:unique name="uniqueTypes">
            <xs:selector xpath="types/type"/>
            <xs:field xpath="."/>
        </xs:unique>
        <xs:unique name="uniqueCategory">
            <xs:selector xpath="category"/>
            <xs:field xpath="."/>
        </xs:unique>
        <xs:unique name="uniqueDatabase">
            <xs:selector xpath="dependencies/database"/>
            <xs:field xpath="."/>
        </xs:unique>
        <xs:unique name="uniqueLib">
            <xs:selector xpath="dependencies/lib"/>
            <xs:field xpath="."/>
        </xs:unique>
        <xs:unique name="uniqueCommand">
            <xs:selector xpath="dependencies/command"/>
            <xs:field xpath="."/>
        </xs:unique>
    </xs:element>

    <!-- basic types -->
    <xs:simpleType name="empty-string">
        <xs:restriction base="xs:string">
            <xs:maxLength value="0"/>
        </xs:restriction>
    </xs:simpleType>
    <xs:simpleType name="non-empty-string">
        <xs:restriction base="xs:string">
            <xs:minLength value="1"/>
        </xs:restriction>
    </xs:simpleType>
    <xs:simpleType name="limited-string">
        <xs:restriction base="non-empty-string">
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="l10n-text">
        <xs:simpleContent>
            <xs:extension base="non-empty-string">
                <xs:attribute name="lang" type="l10n-code" default="en"
                              use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>
    <xs:complexType name="l10n-string">
        <xs:simpleContent>
            <xs:restriction base="l10n-text">
                <xs:maxLength value="128"/>
            </xs:restriction>
        </xs:simpleContent>
    </xs:complexType>


    <xs:simpleType name="l10n-code">
        <xs:restriction base="xs:string">
            <xs:enumeration value="af"/>
            <xs:enumeration value="ar"/>
            <xs:enumeration value="ast"/>
            <xs:enumeration value="az"/>
            <xs:enumeration value="bg"/>
            <xs:enumeration value="be"/>
            <xs:enumeration value="bn"/>
            <xs:enumeration value="br"/>
            <xs:enumeration value="bs"/>
            <xs:enumeration value="ca"/>
            <xs:enumeration value="cs"/>
            <xs:enumeration value="cy"/>
            <xs:enumeration value="da"/>
            <xs:enumeration value="de"/>
            <xs:enumeration value="el"/>
            <xs:enumeration value="en"/>
            <xs:enumeration value="eo"/>
            <xs:enumeration value="es"/>
            <xs:enumeration value="es-ar"/>
            <xs:enumeration value="es-co"/>
            <xs:enumeration value="es-mx"/>
            <xs:enumeration value="es-ni"/>
            <xs:enumeration value="es-ve"/>
            <xs:enumeration value="et"/>
            <xs:enumeration value="eu"/>
            <xs:enumeration value="fa"/>
            <xs:enumeration value="fi"/>
            <xs:enumeration value="fr"/>
            <xs:enumeration value="fy"/>
            <xs:enumeration value="ga"/>
            <xs:enumeration value="gd"/>
            <xs:enumeration value="gl"/>
            <xs:enumeration value="he"/>
            <xs:enumeration value="hi"/>
            <xs:enumeration value="hr"/>
            <xs:enumeration value="hu"/>
            <xs:enumeration value="ia"/>
            <xs:enumeration value="id"/>
            <xs:enumeration value="io"/>
            <xs:enumeration value="is"/>
            <xs:enumeration value="it"/>
            <xs:enumeration value="ja"/>
            <xs:enumeration value="ka"/>
            <xs:enumeration value="kk"/>
            <xs:enumeration value="km"/>
            <xs:enumeration value="kn"/>
            <xs:enumeration value="ko"/>
            <xs:enumeration value="lb"/>
            <xs:enumeration value="lt"/>
            <xs:enumeration value="lv"/>
            <xs:enumeration value="mk"/>
            <xs:enumeration value="ml"/>
            <xs:enumeration value="mn"/>
            <xs:enumeration value="mr"/>
            <xs:enumeration value="my"/>
            <xs:enumeration value="nb"/>
            <xs:enumeration value="ne"/>
            <xs:enumeration value="nl"/>
            <xs:enumeration value="nn"/>
            <xs:enumeration value="os"/>
            <xs:enumeration value="pa"/>
            <xs:enumeration value="pl"/>
            <xs:enumeration value="pt"/>
            <xs:enumeration value="pt-br"/>
            <xs:enumeration value="ro"/>
            <xs:enumeration value="ru"/>
            <xs:enumeration value="sk"/>
            <xs:enumeration value="sl"/>
            <xs:enumeration value="sq"/>
            <xs:enumeration value="sr"/>
            <xs:enumeration value="sr-latn"/>
            <xs:enumeration value="sv"/>
            <xs:enumeration value="sw"/>
            <xs:enumeration value="ta"/>
            <xs:enumeration value="te"/>
            <xs:enumeration value="th"/>
            <xs:enumeration value="tr"/>
            <xs:enumeration value="tt"/>
            <xs:enumeration value="udm"/>
            <xs:enumeration value="uk"/>
            <xs:enumeration value="ur"/>
            <xs:enumeration value="vi"/>
            <xs:enumeration value="zh-hans"/>
            <xs:enumeration value="zh-hant"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="semver">
        <xs:restriction base="limited-string">
            <xs:pattern
                    value="(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)(\-([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)*))?"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="version">
        <xs:restriction base="limited-string">
            <xs:pattern value="[0-9]+(\.[0-9]+){0,2}"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="url">
        <xs:restriction base="xs:anyURI">
            <xs:pattern value="https?://.+"/>
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="doc-user-url">
        <xs:restriction base="non-empty-string">
            <xs:pattern value="https://.+|user-[a-z]+[\-a-z]*[a-z]+"/>
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="doc-admin-url">
        <xs:restriction base="non-empty-string">
            <xs:pattern value="https://.+|admin-[a-z]+[\-a-z]*[a-z]+"/>
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="doc-developer-url">
        <xs:restriction base="non-empty-string">
            <xs:pattern value="https://.+|developer-[a-z]+[\-a-z]*[a-z]+"/>
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="secure-url">
        <xs:restriction base="xs:anyURI">
            <xs:pattern value="https://.+"/>
            <xs:maxLength value="256"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="email">
        <xs:restriction base="limited-string">
            <xs:pattern value="[^@]+@[^\.]+\..+"/>
        </xs:restriction>
    </xs:simpleType>

    <!-- first level elements -->
    <xs:complexType name="screenshot">
        <xs:simpleContent>
            <xs:extension base="secure-url">
                <xs:attribute name="small-thumbnail" use="optional"
                              type="secure-url"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="id">
        <xs:restriction base="limited-string">
            <xs:pattern value="[a-z]+[a-z0-9_]*[a-z0-9]+"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="author">
        <xs:simpleContent>
            <xs:extension base="limited-string">
                <xs:attribute name="mail" type="email" use="optional"/>
                <xs:attribute name="homepage" type="url" use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:complexType name="repository">
        <xs:simpleContent>
            <xs:extension base="url">
                <xs:attribute name="type" type="vcs" use="optional"
                              default="git"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="vcs">
        <xs:restriction base="xs:string">
            <xs:enumeration value="git"/>
            <xs:enumeration value="mercurial"/>
            <xs:enumeration value="subversion"/>
            <xs:enumeration value="bzr"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="types">
        <xs:sequence>
            <xs:element name="prelogin" minOccurs="0" maxOccurs="1"/>
            <xs:element name="filesystem" minOccurs="0" maxOccurs="1"/>
            <xs:element name="authentication" minOccurs="0" maxOccurs="1"/>
            <xs:element name="logging" minOccurs="0" maxOccurs="1"/>
            <xs:element name="dav" minOccurs="0" maxOccurs="1"/>
            <xs:element name="prevent_group_restriction" minOccurs="0"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:simpleType name="category">
        <xs:restriction base="xs:string">
            <xs:enumeration value="security"/>
            <xs:enumeration value="customization"/>
            <xs:enumeration value="files"/>
            <xs:enumeration value="integration"/>
            <xs:enumeration value="monitoring"/>
            <xs:enumeration value="multimedia"/>
            <xs:enumeration value="office"/>
            <xs:enumeration value="organization"/>
            <xs:enumeration value="social"/>
            <xs:enumeration value="tools"/>
            <xs:enumeration value="games"/>
            <xs:enumeration value="search"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="licence">
        <xs:restriction base="xs:string">
            <xs:enumeration value="agpl"/>
            <xs:enumeration value="mpl"/>
            <xs:enumeration value="apache"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="databases">
        <xs:restriction base="xs:string">
            <xs:enumeration value="sqlite"/>
            <xs:enumeration value="mysql"/>
            <xs:enumeration value="pgsql"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="documentation">
        <xs:sequence>
            <xs:element name="user" type="doc-user-url" minOccurs="0" maxOccurs="1"/>
            <xs:element name="admin" type="doc-admin-url" minOccurs="0" maxOccurs="1"/>
            <xs:element name="developer" type="doc-developer-url" minOccurs="0"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="settings">
        <xs:sequence>
            <xs:element name="admin" type="php-class" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="admin-section" type="php-class" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="personal" type="php-class" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="personal-section" type="php-class" minOccurs="0"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="activity">
        <xs:sequence>
            <xs:element name="settings" type="activity-settings" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="filters" type="activity-filters" minOccurs="0" maxOccurs="1"/>
            <xs:element name="providers" type="activity-providers" minOccurs="0"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="activity-settings">
        <xs:sequence>
            <xs:element name="setting" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="activity-filters">
        <xs:sequence>
            <xs:element name="filter" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="activity-providers">
        <xs:sequence>
            <xs:element name="provider" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="navigations">
        <xs:sequence>
            <xs:element name="navigation" type="navigation" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="navigation">
        <xs:sequence>
            <xs:element name="id" type="id" minOccurs="0" maxOccurs="1"/>
            <xs:element name="name" type="non-empty-string" minOccurs="1" maxOccurs="1"/>
            <xs:element name="route" type="route" minOccurs="1" maxOccurs="1"/>
            <xs:element name="icon" type="xs:anyURI" minOccurs="0" maxOccurs="1"/>
            <xs:element name="order" type="xs:int" minOccurs="0" maxOccurs="1"/>
            <xs:element name="type" type="navigation-type" minOccurs="0" maxOccurs="1"/>
        </xs:sequence>
        <xs:attribute name="role" type="navigation-role" default="all" use="optional"/>
    </xs:complexType>

    <xs:simpleType name="navigation-role">
        <xs:restriction base="xs:string">
            <xs:enumeration value="all"/>
            <xs:enumeration value="admin"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="navigation-type">
        <xs:restriction base="xs:string">
            <xs:enumeration value="link"/>
            <xs:enumeration value="settings"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:simpleType name="route">
        <xs:restriction base="non-empty-string">
            <xs:pattern value="[0-9a-zA-Z_]+(\.[0-9a-zA-Z_]+){2}"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="contactsmenu">
        <xs:sequence>
            <xs:element name="provider" type="php-class" minOccurs="1"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="collaboration">
        <xs:sequence>
            <xs:element name="plugins" type="collaboration-plugins" minOccurs="0" maxOccurs="1">
            </xs:element>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="collaboration-plugins">
        <xs:sequence>
            <xs:element name="plugin" type="collaboration-plugins-plugin" minOccurs="1" maxOccurs="unbounded">
            </xs:element>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="collaboration-plugins-plugin">
        <xs:simpleContent>
            <xs:extension base="php-class">
                <xs:attribute name="type" type="collaboration-plugin-type" use="required"/>
                <xs:attribute name="share-type" type="share-type" />
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="collaboration-plugin-type">
        <xs:restriction base="xs:string">
            <xs:enumeration value="collaborator-search"/>
            <xs:enumeration value="autocomplete-sort"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="sabre">
        <xs:sequence>
            <xs:element name="collections" type="sabre-collections" minOccurs="0" maxOccurs="1"/>
            <xs:element name="plugins" type="sabre-plugins" minOccurs="0" maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="sabre-collections">
        <xs:sequence>
            <xs:element name="collection" type="php-class" minOccurs="1" maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="sabre-plugins">
        <xs:sequence>
            <xs:element name="plugin" type="php-class" minOccurs="1" maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:simpleType name="share-type">
        <xs:restriction base="xs:string">
            <xs:enumeration value="SHARE_TYPE_USER"/>
            <xs:enumeration value="SHARE_TYPE_GROUP"/>
            <xs:enumeration value="SHARE_TYPE_LINK"/>
            <xs:enumeration value="SHARE_TYPE_EMAIL"/>
            <xs:enumeration value="SHARE_TYPE_CONTACT"/>
            <xs:enumeration value="SHARE_TYPE_REMOTE"/>
            <xs:enumeration value="SHARE_TYPE_CIRCLE"/>
            <xs:enumeration value="SHARE_TYPE_GUEST"/>
            <xs:enumeration value="SHARE_TYPE_ROOM"/>
        </xs:restriction>
    </xs:simpleType>

    <!-- dependencies -->
    <xs:complexType name="dependencies">
        <xs:sequence>
            <xs:element name="php" type="php" minOccurs="0" maxOccurs="1"/>
            <xs:element name="database" type="database" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="command" type="shell-command" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="lib" type="min-max-version" minOccurs="0"
                        maxOccurs="unbounded"/>
            <xs:element name="owncloud" type="owncloud" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="nextcloud" type="nextcloud" minOccurs="1"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="owncloud">
        <xs:attribute name="min-version" type="version" use="required"/>
        <xs:attribute name="max-version" type="version" use="optional"/>
    </xs:complexType>

    <xs:complexType name="nextcloud">
        <xs:attribute name="min-version" type="version" use="required"/>
        <xs:attribute name="max-version" type="version" use="required"/>
    </xs:complexType>

    <xs:simpleType name="shell-command">
        <xs:restriction base="limited-string">
            <xs:pattern value="[a-zA-Z\-_]+"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="min-max-version">
        <xs:simpleContent>
            <xs:extension base="limited-string">
                <xs:attribute name="min-version" type="version"
                              use="optional"/>
                <xs:attribute name="max-version" type="version"
                              use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:complexType name="database">
        <xs:simpleContent>
            <xs:extension base="databases">
                <xs:attribute name="min-version" type="version"
                              use="optional"/>
                <xs:attribute name="max-version" type="version"
                              use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:complexType name="php">
        <xs:simpleContent>
            <xs:extension base="empty-string">
                <xs:attribute name="min-int-size" type="bits" use="optional"
                              default="32"/>
                <xs:attribute name="min-version" type="version"
                              use="optional"/>
                <xs:attribute name="max-version" type="version"
                              use="optional"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="bits">
        <xs:restriction base="xs:int">
            <xs:enumeration value="32"/>
            <xs:enumeration value="64"/>
        </xs:restriction>
    </xs:simpleType>

    <xs:complexType name="repair-steps">
        <xs:sequence>
            <xs:element name="pre-migration" type="steps" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="post-migration" type="steps" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="live-migration" type="steps" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="install" type="steps" minOccurs="0"
                        maxOccurs="1"/>
            <xs:element name="uninstall" type="steps" minOccurs="0"
                        maxOccurs="1"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="jobs">
        <xs:sequence>
            <xs:element name="job" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="steps">
        <xs:sequence>
            <xs:element name="step" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="two-factor-providers">
        <xs:sequence>
            <xs:element name="provider" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="commands">
        <xs:sequence>
            <xs:element name="command" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="dashboard">
        <xs:sequence>
            <xs:element name="widget" type="php-class" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="trash">
        <xs:sequence>
            <xs:element name="backend" type="trash-backend" minOccurs="1"
                        maxOccurs="unbounded"/>
        </xs:sequence>
    </xs:complexType>

    <xs:complexType name="trash-backend">
        <xs:simpleContent>
            <xs:extension base="php-class">
                <xs:attribute name="for" type="php-class" use="required"/>
            </xs:extension>
        </xs:simpleContent>
    </xs:complexType>

    <xs:simpleType name="php-class">
        <xs:restriction base="xs:string">
            <xs:pattern
                    value="[a-zA-Z_][0-9a-zA-Z_]*(\\[a-zA-Z_][0-9a-zA-Z_]*)*"/>
        </xs:restriction>
    </xs:simpleType>
</xs:schema>