Provides build builders for handling XML.
The builders generate code when they find members annotated with classes defined in xml_annotation.
- Define the XML document that you would like to serialize.
<?xml version="1.0"?> <bookshelf> <book> <title lang="English">XML Pocket Reference</title> <author>Simon St. Laurent</author> <author>Michael James Fitzgerald</author> <price></price> </book> <book> <title lang="English">HTML and XHTML Pocket Reference</title> <author>Jennifer Niederst Robbins</author> <price></price> </book> </bookshelf>
- Add the necessary classes to model the XML document.
class Book { Title? title; List<String>? authors; String? price; Book({ this.title, this.authors, this.price, }); } class Bookshelf { List<Book>? books; String? price; Bookshelf({ this.books, this.price, }); } enum Language { mandarin, spanish, english, hindi, bengali, } class Title { Language? language; String? text; Title({ this.language, this.text, }); }
- Annotate the classes and properties with XML annotations.
@annotation.XmlRootElement(name: 'book') @annotation.XmlSerializable() class Book { @annotation.XmlElement(name: 'title') Title? title; @annotation.XmlElement(name: 'author') List<String>? authors; @annotation.XmlElement(name: 'price', isSelfClosing: false) String? price; Book({ this.title, this.authors, this.price, }); } @annotation.XmlRootElement(name: 'bookshelf') @annotation.XmlSerializable() class Bookshelf { @annotation.XmlElement(name: 'book') List<Book>? books; @annotation.XmlElement(name: 'price', includeIfNull: false) String? price; Bookshelf({ this.books, this.price, }); } @annotation.XmlEnum(fieldRename: annotation.FieldRename.pascal) enum Language { mandarin, spanish, english, hindi, bengali, } @annotation.XmlRootElement(name: 'title') @annotation.XmlSerializable() class Title { @annotation.XmlAttribute(name: 'lang') Language? language; @annotation.XmlText() String? text; Title({ this.language, this.text, }); }
- Add the required serialization helper methods to the classes.
@annotation.XmlRootElement(name: 'book') @annotation.XmlSerializable() class Book { @annotation.XmlElement(name: 'title') Title? title; @annotation.XmlElement(name: 'author') List<String>? authors; @annotation.XmlElement(name: 'price', isSelfClosing: false) String? price; Book({ this.title, this.authors, this.price, }); factory Book.fromXmlElement(XmlElement element) => _$BookFromXmlElement(element); @override String toString() { return 'Book{title: $title, authors: $authors, price: $price}'; } void buildXmlChildren( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$BookBuildXmlChildren( this, builder, namespaces: namespaces, ); void buildXmlElement( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$BookBuildXmlElement( this, builder, namespaces: namespaces, ); List<XmlAttribute> toXmlAttributes({ Map<String, String?> namespaces = const {}, }) => _$BookToXmlAttributes( this, namespaces: namespaces, ); List<XmlNode> toXmlChildren({ Map<String, String?> namespaces = const {}, }) => _$BookToXmlChildren( this, namespaces: namespaces, ); XmlElement toXmlElement({ Map<String, String?> namespaces = const {}, }) => _$BookToXmlElement( this, namespaces: namespaces, ); } @annotation.XmlRootElement(name: 'bookshelf') @annotation.XmlSerializable() class Bookshelf { @annotation.XmlElement(name: 'book') List<Book>? books; @annotation.XmlElement(name: 'price', includeIfNull: false) String? price; Bookshelf({ this.books, this.price, }); factory Bookshelf.fromXmlElement(XmlElement element) => _$BookshelfFromXmlElement(element); @override String toString() { return 'Bookshelf{books: $books, price: $price}'; } void buildXmlChildren( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$BookshelfBuildXmlChildren( this, builder, namespaces: namespaces, ); void buildXmlElement( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$BookshelfBuildXmlElement( this, builder, namespaces: namespaces, ); List<XmlAttribute> toXmlAttributes({ Map<String, String?> namespaces = const {}, }) => _$BookshelfToXmlAttributes( this, namespaces: namespaces, ); List<XmlNode> toXmlChildren({ Map<String, String?> namespaces = const {}, }) => _$BookshelfToXmlChildren( this, namespaces: namespaces, ); XmlElement toXmlElement({ Map<String, String?> namespaces = const {}, }) => _$BookshelfToXmlElement( this, namespaces: namespaces, ); } @annotation.XmlEnum(fieldRename: annotation.FieldRename.pascal) enum Language { mandarin, spanish, english, hindi, bengali, } @annotation.XmlRootElement(name: 'title') @annotation.XmlSerializable() class Title { @annotation.XmlAttribute(name: 'lang') Language? language; @annotation.XmlText() String? text; Title({ this.language, this.text, }); factory Title.fromXmlElement(XmlElement element) => _$TitleFromXmlElement(element); @override String toString() { return 'Title{language: $language, text: $text}'; } void buildXmlChildren( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$TitleBuildXmlChildren( this, builder, namespaces: namespaces, ); void buildXmlElement( XmlBuilder builder, { Map<String, String> namespaces = const {}, }) => _$TitleBuildXmlElement( this, builder, namespaces: namespaces, ); List<XmlAttribute> toXmlAttributes({ Map<String, String?> namespaces = const {}, }) => _$TitleToXmlAttributes( this, namespaces: namespaces, ); List<XmlNode> toXmlChildren({ Map<String, String?> namespaces = const {}, }) => _$TitleToXmlChildren( this, namespaces: namespaces, ); XmlElement toXmlElement({ Map<String, String?> namespaces = const {}, }) => _$TitleToXmlElement( this, namespaces: namespaces, ); }
- Add a part directive to the file that contains the classes.
part 'example.g.dart';
- Add the required package dependencies to your project.
dart pub add xml xml_annotation dev:build_runner dev:xml_serializable
- Run the build runner to generate the serializer code.
dart run build_runner build
- Verify that the generated serializer output is as expected.
// GENERATED CODE - DO NOT MODIFY BY HAND part of 'example.dart'; // ************************************************************************** // XmlEnumGenerator // ************************************************************************** const $LanguageEnumMap = { Language.mandarin: 'Mandarin', Language.spanish: 'Spanish', Language.english: 'English', Language.hindi: 'Hindi', Language.bengali: 'Bengali' }; // ************************************************************************** // XmlSerializableGenerator // ************************************************************************** void _$BookBuildXmlChildren(Book instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { final title = instance.title; final titleSerialized = title; builder.element('title', nest: () { if (titleSerialized != null) { titleSerialized.buildXmlChildren(builder, namespaces: namespaces); } }); final authors = instance.authors; final authorsSerialized = authors; if (authorsSerialized != null) { for (final value in authorsSerialized) { builder.element('author', nest: () { builder.text(value); }); } } final price = instance.price; final priceSerialized = price; builder.element('price', isSelfClosing: false, nest: () { if (priceSerialized != null) { builder.text(priceSerialized); } }); } void _$BookBuildXmlElement(Book instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { builder.element('book', namespaces: namespaces, nest: () { instance.buildXmlChildren(builder, namespaces: namespaces); }); } Book _$BookFromXmlElement(XmlElement element) { final title = element.getElement('title'); final authors = element .getElements('author') ?.map((e) => e.getText()) .whereType<String>(); final price = element.getElement('price')?.getText(); return Book( title: title != null ? Title.fromXmlElement(title) : null, authors: authors?.toList(), price: price); } List<XmlAttribute> _$BookToXmlAttributes(Book instance, {Map<String, String?> namespaces = const {}}) { final attributes = <XmlAttribute>[]; return attributes; } List<XmlNode> _$BookToXmlChildren(Book instance, {Map<String, String?> namespaces = const {}}) { final children = <XmlNode>[]; final title = instance.title; final titleSerialized = title; final titleConstructed = XmlElement( XmlName('title'), titleSerialized?.toXmlAttributes(namespaces: namespaces) ?? [], titleSerialized?.toXmlChildren(namespaces: namespaces) ?? []); children.add(titleConstructed); final authors = instance.authors; final authorsSerialized = authors; final authorsConstructed = authorsSerialized ?.map((e) => XmlElement(XmlName('author'), [], [XmlText(e)])); if (authorsConstructed != null) { children.addAll(authorsConstructed); } final price = instance.price; final priceSerialized = price; final priceConstructed = XmlElement(XmlName('price'), [], priceSerialized != null ? [XmlText(priceSerialized)] : [], false); children.add(priceConstructed); return children; } XmlElement _$BookToXmlElement(Book instance, {Map<String, String?> namespaces = const {}}) { return XmlElement( XmlName('book'), [ ...namespaces.toXmlAttributes(), ...instance.toXmlAttributes(namespaces: namespaces) ], instance.toXmlChildren(namespaces: namespaces)); } void _$BookshelfBuildXmlChildren(Bookshelf instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { final books = instance.books; final booksSerialized = books; if (booksSerialized != null) { for (final value in booksSerialized) { builder.element('book', nest: () { value.buildXmlChildren(builder, namespaces: namespaces); }); } } final price = instance.price; final priceSerialized = price; if (priceSerialized != null) { builder.element('price', nest: () { builder.text(priceSerialized); }); } } void _$BookshelfBuildXmlElement(Bookshelf instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { builder.element('bookshelf', namespaces: namespaces, nest: () { instance.buildXmlChildren(builder, namespaces: namespaces); }); } Bookshelf _$BookshelfFromXmlElement(XmlElement element) { final books = element.getElements('book'); final price = element.getElement('price')?.getText(); return Bookshelf( books: books?.map((e) => Book.fromXmlElement(e)).toList(), price: price); } List<XmlAttribute> _$BookshelfToXmlAttributes(Bookshelf instance, {Map<String, String?> namespaces = const {}}) { final attributes = <XmlAttribute>[]; return attributes; } List<XmlNode> _$BookshelfToXmlChildren(Bookshelf instance, {Map<String, String?> namespaces = const {}}) { final children = <XmlNode>[]; final books = instance.books; final booksSerialized = books; final booksConstructed = booksSerialized?.map((e) => XmlElement( XmlName('book'), e.toXmlAttributes(namespaces: namespaces), e.toXmlChildren(namespaces: namespaces))); if (booksConstructed != null) { children.addAll(booksConstructed); } final price = instance.price; final priceSerialized = price; final priceConstructed = priceSerialized != null ? XmlElement(XmlName('price'), [], [XmlText(priceSerialized)]) : null; if (priceConstructed != null) { children.add(priceConstructed); } return children; } XmlElement _$BookshelfToXmlElement(Bookshelf instance, {Map<String, String?> namespaces = const {}}) { return XmlElement( XmlName('bookshelf'), [ ...namespaces.toXmlAttributes(), ...instance.toXmlAttributes(namespaces: namespaces) ], instance.toXmlChildren(namespaces: namespaces)); } void _$TitleBuildXmlChildren(Title instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { final language = instance.language; final languageSerialized = language != null ? $LanguageEnumMap[language]! : null; if (languageSerialized != null) { builder.attribute('lang', languageSerialized); } final text = instance.text; final textSerialized = text; if (textSerialized != null) { builder.text(textSerialized); } } void _$TitleBuildXmlElement(Title instance, XmlBuilder builder, {Map<String, String> namespaces = const {}}) { builder.element('title', namespaces: namespaces, nest: () { instance.buildXmlChildren(builder, namespaces: namespaces); }); } Title _$TitleFromXmlElement(XmlElement element) { final language = element.getAttribute('lang'); final text = element.getText(); return Title( language: language != null ? $LanguageEnumMap.entries .singleWhere( (languageEnumMapEntry) => languageEnumMapEntry.value == language, orElse: () => throw ArgumentError( '`$language` is not one of the supported values: ${$LanguageEnumMap.values.join(', ')}')) .key : null, text: text); } List<XmlAttribute> _$TitleToXmlAttributes(Title instance, {Map<String, String?> namespaces = const {}}) { final attributes = <XmlAttribute>[]; final language = instance.language; final languageSerialized = language != null ? $LanguageEnumMap[language]! : null; final languageConstructed = languageSerialized != null ? XmlAttribute(XmlName('lang'), languageSerialized) : null; if (languageConstructed != null) { attributes.add(languageConstructed); } return attributes; } List<XmlNode> _$TitleToXmlChildren(Title instance, {Map<String, String?> namespaces = const {}}) { final children = <XmlNode>[]; final text = instance.text; final textSerialized = text; final textConstructed = textSerialized != null ? XmlText(textSerialized) : null; if (textConstructed != null) { children.add(textConstructed); } return children; } XmlElement _$TitleToXmlElement(Title instance, {Map<String, String?> namespaces = const {}}) { return XmlElement( XmlName('title'), [ ...namespaces.toXmlAttributes(), ...instance.toXmlAttributes(namespaces: namespaces) ], instance.toXmlChildren(namespaces: namespaces)); }