Use method instead for nicer DX

saloonphp · Nov 5, 2023 · 2c2a9b0 · 2c2a9b0
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diff --git a/.github/README.md b/.github/README.md
@@ -181,17 +181,6 @@ $reader->value('song')->get(); // ['Luke Combs - When It Rains It Pours', 'Sam R
 
 $reader->value('song.2')->sole(); // 'London Symfony Orchestra - Starfield Suite'
 ```
-#### Reading Specific Values via XPath
-You can use the `xpathValue` method to find a specific element's value with an [XPath](https://devhints.io/xpath) query. This method will return a `Query` class which has different methods to retrieve the data.
-```php
-<?php
-
-$reader = XmlReader::fromString(...);
-
-$reader->xpathValue('//person/favourite-songs/song[3]')->sole(); //  'London Symfony Orchestra - Starfield Suite'
-```
->**Warning**
->This method is not memory safe as XPath requires all the XML to be loaded in memory at once.
 #### Reading Specific Elements
 You can use the `element` method to search for a specific element. You can use dot-notation to search for child elements. You can also use whole numbers to find specific positions of multiple elements. This method searches through the whole XML body in a memory efficient way.
 
@@ -215,18 +204,6 @@ $reader->element('song')->get(); // [Element('Luke Combs - When It Rains It Pour
 
 $reader->element('song.2')->sole(); // Element('London Symfony Orchestra - Starfield Suite')
 ```
-#### Reading Specific Elements via XPath
-You can use the `xpathElement` method to find a specific element with an [XPath](https://devhints.io/xpath) query. This method will return a `Query` class which has different methods to retrieve the data.
-```php
-<?php
-
-$reader = XmlReader::fromString(...);
-
-$reader->xpathElement('//person/favourite-songs/song[3]')->sole(); //  Element('London Symfony Orchestra - Starfield Suite')
-```
->**Warning**
->This method is not memory safe as XPath requires all the XML to be loaded in memory at once.
-
 #### Lazily Iterating
 When searching a large file, you can use the `lazy` or `collectLazy` methods which will return a generator of results only keeping one item in memory at a time.
 ```php
@@ -243,7 +220,61 @@ $names = $reader->value('name')->collect();
 
 $names = $reader->value('name')->collectLazy();
 ```
+#### Searching for specific elements
+Sometimes you might want to search for a specific element or value where the element contains a specific attribute. You can do this by providing a second argument to the `value` or `element` method. This will search the last element for the attributes and will return if they match.
+```php
+$reader = XmlReader::fromString('
+    <?xml version="1.0" encoding="utf-8"?>
+    <person>
+        <name>Sammyjo20</name>
+        <favourite-songs>
+            <song>Luke Combs - When It Rains It Pours</song>
+            <song>Sam Ryder - SPACE MAN</song>
+            <song recent="true">London Symfony Orchestra - Starfield Suite</song>
+        </favourite-songs>
+    </person>
+');
+
+$reader->element('song', ['recent' => 'true'])->sole(); // Element('London Symfony Orchestra - Starfield Suite')
+
+$reader->value('song', ['recent' => 'true'])->sole(); // 'London Symfony Orchestra - Starfield Suite'
+```
+### Reading with XPath
+XPath is a fantastic way to search through XML. With one string, you can search for a specific element, with specific attributes or indexes. If you are interested in learning XPath, you can [click here for a useful cheatsheet](https://devhints.io/xpath).
+
+#### Reading Specific Elements via XPath
+You can use the `xpathElement` method to find a specific element with an [XPath](https://devhints.io/xpath) query. This method will return a `Query` class which has different methods to retrieve the data.
+```php
+<?php
+
+$reader = XmlReader::fromString(...);
+
+$reader->xpathElement('//person/favourite-songs/song[3]')->sole(); //  Element('London Symfony Orchestra - Starfield Suite')
+```
+#### Reading Specific Values via XPath
+You can use the `xpathValue` method to find a specific element's value with an [XPath](https://devhints.io/xpath) query. This method will return a `Query` class which has different methods to retrieve the data.
+```php
+<?php
+$reader = XmlReader::fromString(...);
 
+$reader->xpathValue('//person/favourite-songs/song[3]')->sole(); //  'London Symfony Orchestra - Starfield Suite'
+```
+>**Warning**
+>Due to limitations with XPath - the above methods used to query with XPath are not memory safe and may not be suitable for large XML documents.
+#### XPath and un-prefixed namespaces
+You might found yourself with an XML document that contains an un-prefixed `xmlns` attribute - like this:
+```xml
+<container xmlns="http://example.com/xml-wrangler/person" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" />
+```
+When this happens, XML Wrangler will automatically remove these un-prefixed namespaces to improve compatability. If you would like to keep these namespaces, you can use `setXpathNamespaceMap` to map each un-prefixed XML namespace.
+```php
+$reader = XmlReader::fromString(...);
+$reader->setXpathNamespaceMap([
+    'root' => 'http://example.com/xml-wrangler/person',
+]);
+
+$reader->xpathValue('//root:person/root:favourite-songs/root:song[3]')->sole();
+```
 ### Writing XML
 This section on the documentation is for using the XML writer.
 #### Basic Usage

diff --git a/src/XmlReader.php b/src/XmlReader.php
@@ -36,6 +36,15 @@ class XmlReader
      */
     protected mixed $streamFile = null;
 
+    /**
+     * XPath namespace map
+     *
+     * Used to map un-prefixed namespaces
+     *
+     * @var array<string, string>
+     */
+    protected array $xpathNamespaceMap = [];
+
     /**
      * Constructor
      *
@@ -269,16 +278,16 @@ public function element(string $name, array $withAttributes = []): LazyQuery
     /**
      * Search for an element with xpath
      *
-     * @param array<string, string> $namespaceMap
      * @throws \Throwable
      * @throws \VeeWee\Xml\Encoding\Exception\EncodingException
      */
-    public function xpathElement(string $query, array $namespaceMap = []): Query
+    public function xpathElement(string $query): Query
     {
         try {
             $xml = $this->reader->provide(Matcher\document_element())->current();
 
             $xpathConfigurators = [];
+            $namespaceMap = $this->xpathNamespaceMap;
 
             // When the namespace map is empty we will remove the root namespaces
             // because if they are not mapped then you cannot search on them.
@@ -345,15 +354,14 @@ public function value(string $name, array $attributes = []): LazyQuery
     /**
      * Find and retrieve value of element
      *
-     * @param array<string, string> $namespaceMap
      * @throws \Saloon\XmlWrangler\Exceptions\XmlReaderException
      * @throws \Throwable
      * @throws \VeeWee\Xml\Encoding\Exception\EncodingException
      */
-    public function xpathValue(string $query, array $namespaceMap = []): Query
+    public function xpathValue(string $query): Query
     {
-        $generator = function () use ($query, $namespaceMap) {
-            yield from $this->xpathElement($query, $namespaceMap)->get();
+        $generator = function () use ($query) {
+            yield from $this->xpathElement($query)->get();
         };
 
         return new Query($query, $this->convertElementArrayIntoValues($generator()));
@@ -435,6 +443,20 @@ protected function convertArrayIntoElements(?string $key, mixed $value): array|E
         return [$key => $element];
     }
 
+    /**
+     * Set the XPath namespace map
+     *
+     * Used to map un-prefixed namespaces
+     *
+     * @param array<string, string> $xpathNamespaceMap
+     */
+    public function setXpathNamespaceMap(array $xpathNamespaceMap): XmlReader
+    {
+        $this->xpathNamespaceMap = $xpathNamespaceMap;
+
+        return $this;
+    }
+
     /**
      * Handle destructing the reader
      *

diff --git a/tests/Feature/XmlReaderTest.php b/tests/Feature/XmlReaderTest.php
@@ -487,9 +487,10 @@
 
     // Or we can map them and they will be searchable
 
+    $reader->setXpathNamespaceMap(['root' => 'http://symfony.com/schema/dic/services']);
+
     $mappedXpathElement = $reader->xpathElement(
-        query: '/root:container/root:services/root:service[@id="service_container"]',
-        namespaceMap: ['root' => 'http://symfony.com/schema/dic/services']
+        '/root:container/root:services/root:service[@id="service_container"]',
     )->sole();
 
     expect($mappedXpathElement)->toEqual(
@@ -513,6 +514,8 @@
 
     // Test we can query xpath element
 
+    $reader->setXpathNamespaceMap([]);
+
     $xpathTags = $reader->xpathElement('/container/services/service/tag')->get();
 
     expect($xpathTags)->toEqual([
@@ -522,26 +525,28 @@
 
     // Test we can query xpath elements with mapping
 
+    $reader->setXpathNamespaceMap([
+        'root' => 'http://symfony.com/schema/dic/services',
+        'tag-1' => 'http://symfony.com/schema/dic/tag-1',
+        'tag-2' => 'http://symfony.com/schema/dic/tag-2',
+    ]);
+
     $mappedXpathTag = $reader->xpathElement(
-        query: '/root:container/root:services/root:service/tag-1:tag',
-        namespaceMap: [
-            'root' => 'http://symfony.com/schema/dic/services',
-            'tag-1' => 'http://symfony.com/schema/dic/tag-1',
-            'tag-2' => 'http://symfony.com/schema/dic/tag-2',
-        ],
+        '/root:container/root:services/root:service/tag-1:tag',
     )->sole();
 
     expect($mappedXpathTag)->toEqual(Element::make('1')
         ->setAttributes(['name' => 'controller.service_arguments', 'xmlns' => 'http://symfony.com/schema/dic/tag-1']));
 
     // Works with XPath Element
 
+    $reader->setXpathNamespaceMap([
+        'root' => 'http://symfony.com/schema/dic/services',
+        'tag-1' => 'http://symfony.com/schema/dic/tag-1',
+    ]);
+
     $mappedXpathTag = $reader->xpathValue(
         query: '/root:container/root:services/root:service/tag-1:tag',
-        namespaceMap: [
-            'root' => 'http://symfony.com/schema/dic/services',
-            'tag-1' => 'http://symfony.com/schema/dic/tag-1',
-        ],
     )->sole();
 
     expect($mappedXpathTag)->toBe('1');