Add support for lower case headers in pagination (#57)

* Add support for lower case headers in pagination
In some cases the webserver only return lower case headers which leads to an error
being thrown when the pagination tries to index the array with headers.

This adds methods to fix this issue.

* Moved opening brace to new line

* Fix styling

---------

Co-authored-by: pixelpeter <[email protected]>
Co-authored-by: pixelpeter <[email protected]>

Author: stromgren

README.md

@@ -194,6 +194,16 @@ Woocommerce::hasNotPreviousPage(); // false
 Woocommerce::hasNotNextPage(); // false
 ```
 
+In some cases the web server returns headers only in lower case. This may cause errors when
+using the pagination functions. If that is your case, call the following method before calling 
+any pagination methods.
+
+```php
+use Woocommerce;
+
+Woocommerce::useLowerCaseHeaders();
+```
+
 ### HTTP Request & Response (Headers)
 
 ```php
@@ -212,7 +222,6 @@ Woocommerce::getResponse();
 Woocommerce::getResponse()->getHeaders()['X-WP-Total']
 ```
 
-
 ### More Examples
 Refer to [WooCommerce REST API Documentation](https://woocommerce.github.io/woocommerce-rest-api-docs) for more examples and documention.
 

src/WoocommerceClient.php

@@ -14,6 +14,11 @@ class WoocommerceClient
      */
     protected $client;
 
+    /**
+     * @var bool
+     */
+    protected $usingLowerCaseHeaders = false;
+
     public function __construct(Client $client)
     {
         $this->client = $client;
@@ -124,7 +129,7 @@ public function currentPage()
      */
     public function totalResults()
     {
-        return (int) $this->getResponse()->getHeaders()['X-WP-Total'];
+        return (int) $this->getResponse()->getHeaders()[$this->getHeaderWithCase('X-WP-Total')];
     }
 
     /**
@@ -134,7 +139,7 @@ public function totalResults()
      */
     public function totalPages()
     {
-        return (int) $this->getResponse()->getHeaders()['X-WP-TotalPages'];
+        return (int) $this->getResponse()->getHeaders()[$this->getHeaderWithCase('X-WP-TotalPages')];
     }
 
     /**
@@ -208,4 +213,31 @@ public function hasNotPreviousPage()
     {
         return (bool) ! $this->previousPage();
     }
+
+    /**
+     * Set if headers should be indexed using lower case
+     */
+    public function useLowerCaseHeaders()
+    {
+        $this->usingLowerCaseHeaders = true;
+    }
+
+    /**
+     * Set if headers should be case sensitive
+     */
+    public function useCaseSensitiveHeaders()
+    {
+        $this->usingLowerCaseHeaders = false;
+    }
+
+    /**
+     * Convert header to correct case
+     *
+     *
+     * @return string
+     */
+    public function getHeaderWithCase($header)
+    {
+        return $this->usingLowerCaseHeaders ? strtolower($header) : $header;
+    }
 }

tests/WoocommerceClient.php

@@ -274,6 +274,22 @@ public function pagination_next_page_returns_valid_page_number()
         $this->assertFalse($this->woocommerce->hasNotNextPage());
     }
 
+    /**
+     * @test
+     */
+    public function headers_are_converted_to_lower_case_when_requested()
+    {
+        $header = 'X-Test-Header';
+
+        $this->woocommerce->useCaseSensitiveHeaders();
+
+        $this->assertEquals($header, $this->woocommerce->getHeaderWithCase($header));
+
+        $this->woocommerce->useLowerCaseHeaders();
+
+        $this->assertEquals(strtolower($header), $this->woocommerce->getHeaderWithCase($header));
+    }
+
     /**
      * tear down
      */