Improve writer implementation

docs/writer.md

@@ -42,6 +42,7 @@ The Writer consists out of following composable blocks:
 
 - [Builders](#builders): Lets you build XML by using a declarative API.
 - [Configurators](#configurators): Configure how the Writer behaves.
+- [Mappers](#mappers): Map the XMLWriter to something else.
 - [Openers](#openers): Specify where you want to write to.
 
 ## Builders
@@ -123,6 +124,24 @@ element('foo',
 <foo hello="world" bar="baz" />
 ```
 
+#### cdata
+
+Writes a CDATA section:
+
+```php
+use function VeeWee\Xml\Dom\Builder\value;
+use function VeeWee\Xml\Writer\Builder\cdata;
+use function VeeWee\Xml\Writer\Builder\element;
+
+element('foo',
+    cdata(value('some cdata'))
+);
+```
+
+```xml
+<foo><![CDATA[some cdata]]></foo>
+```
+
 #### children
 
 Inserts multiple nodes at current position in the writer.
@@ -164,6 +183,24 @@ function myOwnDataBuilder(): Generator
 children(myOwnDataBuilder());
 ```
 
+#### comment
+
+Writes a comment section:
+
+```php
+use function VeeWee\Xml\Dom\Builder\value;
+use function VeeWee\Xml\Writer\Builder\comment;
+use function VeeWee\Xml\Writer\Builder\element;
+
+element('foo',
+    comment(value('some comment'))
+);
+```
+
+```xml
+<foo><!--some comment--></foo>
+```
+
 #### document
 
 This builder can be used to specify an XML version and charset.
@@ -218,6 +255,65 @@ element('foo',
 <foo xmlns="https://acme.com" xmlns:hello="https://helloworld.com" />
 ```
 
+
+#### namespaced_attribute
+
+Can be used to add a namespaced attribute with or without prefix.
+This function will also add the xmlns attribute.
+
+```php
+use function VeeWee\Xml\Writer\Builder\element;
+use function VeeWee\Xml\Writer\Builder\namespaced_attribute;
+
+element('foo',
+    namespaced_attribute('https://acme.com', 'acme', 'hello', world)
+);
+```
+
+```xml
+<foo xmlns:acme="https://acme.com" acme:hello="world" />
+```
+
+#### namespaced_attributes
+
+Can be used to add multiple namespaced attributes with or without prefix at once.
+This function will add the xmlns attribute.
+
+```php
+use function VeeWee\Xml\Writer\Builder\element;
+use function VeeWee\Xml\Writer\Builder\namespaced_attributes;
+
+element('foo',
+    namespaced_attributes('https://acme.com', [
+        'acme:hello' => 'world',
+        'acme:foo' => 'bar',
+    ])
+);
+```
+
+```xml
+<foo xmlns:acme="https://acme.com" acme:hello="world" acme:foo="bar" />
+```
+
+#### namespaced_element
+
+Build a namespaced element.
+It can contain a set of configurators that can be used to specify the attributes, children, value, ... of the element with or without prefix.
+This function will add the xmlns attribute.
+
+```php
+use function VeeWee\Xml\Writer\Builder\namespace_attribute;
+use function VeeWee\Xml\Writer\Builder\prefixed_element;
+
+namespaced_element('http://acme.com', 'acme', 'hello',
+    ...$configurators
+);
+```
+
+```xml
+<acme:hello xmlns:acme="http://acme.com" />
+```
+
 #### prefixed_attribute
 
 Can be used to add a namespaced prefixed attribute.
@@ -281,6 +377,21 @@ prefixed_element('acme', 'hello',
 <acme:hello xmlns:acme="http://acme.com" />
 ```
 
+#### raw
+
+Can be used to insert raw strings into the XML.
+Be careful: these strings won't be validated or escaped and are just appended to the XML without any sort of validation. 
+
+```php
+use function VeeWee\Xml\Writer\Builder\raw;
+
+raw('<hello>world</hello>');
+```
+
+```xml
+<hello>world</hello>
+```
+
 #### value
 
 Can set a value to any XML element.
@@ -389,8 +500,37 @@ use VeeWee\Xml\Writer\Writer;
 $document = Writer::configure(...$configurators);
 ```
 
+## Mapper
+
+#### memory_output
+
+If you are using an in-memory writer, you can use the `memory_output()` mapper to get the written content as a string.
+
+```php
+use VeeWee\Xml\Writer\Writer;
+use function VeeWee\Xml\Writer\Mapper\memory_output;
+
+$doc = Writer::inMemory()
+    ->write($yourXml)
+    ->map(memory_output());
+```
+
 ## Openers
 
+#### memory_opener
+
+Starts a writer that stores the written XML in-memory.
+You can use the [memory_output](#memoryoutput) mapper to retrieve the written XML.
+
+```php
+use VeeWee\Xml\Writer\Writer;
+use function VeeWee\Xml\Writer\Mapper\memory_output;
+
+$doc = Writer::inMemory(...$configurators)
+    ->write($yourXml)
+    ->map(memory_output());
+```
+
 #### xml_file_opener
 
 Loads an XML document from a file.

src/Xml/Writer/Builder/cdata.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @param list<(callable(XMLWriter): Generator<bool>)> $configurators
+ *
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function cdata(callable ...$configurators): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($configurators): Generator {
+            yield $writer->startCdata();
+            foreach ($configurators as $configurator) {
+                yield from $configurator($writer);
+            }
+
+            yield $writer->endCdata();
+        };
+}

src/Xml/Writer/Builder/comment.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @param list<(callable(XMLWriter): Generator<bool>)> $configurators
+ *
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function comment(callable ...$configurators): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($configurators): Generator {
+            yield $writer->startComment();
+            foreach ($configurators as $configurator) {
+                yield from $configurator($writer);
+            }
+
+            yield $writer->endComment();
+        };
+}

src/Xml/Writer/Builder/namespaced_attribute.php

@@ -0,0 +1,25 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function namespaced_attribute(string $namespace, ?string $prefix, string $name, string $value): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($namespace, $prefix, $name, $value): Generator {
+            yield $writer->startAttributeNs($prefix, $name, $namespace);
+            yield $writer->text($value);
+            yield $writer->endAttribute();
+        };
+}

src/Xml/Writer/Builder/namespaced_attributes.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @param array<string, string> $attributes
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function namespaced_attributes(string $namespace, array $attributes): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($namespace, $attributes): Generator {
+            foreach ($attributes as $key => $value) {
+                $parts = explode(':', $key, 2);
+                $name = array_pop($parts);
+                $prefix = $parts ? $parts[0] : null;
+
+                yield from namespaced_attribute($namespace, $prefix, $name, $value)($writer);
+            }
+        };
+}

src/Xml/Writer/Builder/namespaced_element.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @param list<(callable(XMLWriter): Generator<bool>)> $configurators
+ *
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function namespaced_element(string $namespace, ?string $prefix, string $name, callable ...$configurators): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($namespace, $prefix, $name, $configurators): Generator {
+            yield $writer->startElementNs($prefix, $name, $namespace);
+            foreach ($configurators as $configurator) {
+                yield from $configurator($writer);
+            }
+
+            yield $writer->endElement();
+        };
+}

src/Xml/Writer/Builder/raw.php

@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Builder;
+
+use Closure;
+use Generator;
+use XMLWriter;
+
+/**
+ * @return Closure(XMLWriter): Generator<bool>
+ */
+function raw(string $value): Closure
+{
+    return
+        /**
+         * @return Generator<bool>
+         */
+        static function (XMLWriter $writer) use ($value): Generator {
+            yield $writer->writeRaw($value);
+        };
+}

src/Xml/Writer/Mapper/memory_output.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Mapper;
+
+use Closure;
+use XMLWriter;
+
+/**
+ * @return Closure(XMLWriter): string XMLWriter
+ */
+function memory_output(): Closure
+{
+    return static function (XMLWriter $writer): string {
+        return $writer->outputMemory();
+    };
+}

src/Xml/Writer/Opener/memory_opener.php

@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace VeeWee\Xml\Writer\Opener;
+
+use Closure;
+use XMLWriter;
+
+/**
+ * @return Closure(XMLWriter): bool XMLWriter
+ */
+function memory_opener(): Closure
+{
+    return static function (XMLWriter $writer): bool {
+        return $writer->openMemory();
+    };
+}