update

README.md

 - "pageLimits": Restricts list operations to prevent database scraping
 - "joinLimits": Restricts join parameters to prevent database scraping
 - "customization": Provides handlers for request and response customization
+- "xml": Translates all input and output from JSON to XML
 
 The "middlewares" config parameter is a comma separated list of enabled middlewares.
 You can tune the middleware behavior using middleware specific configuration parameters:
 - "joinLimits.records": The maximum number of records returned for a joined entity ("1000")
 - "customization.beforeHandler": Handler to implement request customization ("")
 - "customization.afterHandler": Handler to implement response customization ("")
+- "xml.objectElement": The XML element name to use for objects ("object")
 
 If you don't specify these parameters in the configuration, then the default values (between brackets) are used.
 
 
 The above example will add a header "X-Time-Taken" with the number of seconds the API call has taken.
 
+### XML middleware
+
+You may use the "xml" middleware to translate input and output from JSON to XML. This request:
+
+    GET /records/posts/1?format=xml
+
+Gives this outputs (it uses a "format" query parameter):
+
+    <object><id>1</id><user_id>1</user_id><category_id>1</category_id><content>blog started</content></object>
+
+This functionality is disabled by default and must be enabled using the "middlewares" configuration setting.
+
 ### File uploads
 
 File uploads are supported through the [FileReader API](https://caniuse.com/#feat=filereader), check out the [example](https://github.com/mevdschee/php-crud-api/blob/master/examples/clients/upload/vanilla.html).