Magento cannot override Sales_Model_Order_Api.php file

Question

I am trying to override Sales/Model/Order/Api.php file. but it going to core file. and i am getting that sales_order_api in rewrite collection with below script

 <?php
    $folders = array('app/code/local/', 'app/code/community/');//folders to parse
    $configFiles = array();
    foreach ($folders as $folder){
        $files = glob($folder.'*/*/etc/config.xml');//get all config.xml files in the specified folder
        $configFiles = array_merge($configFiles, $files);//merge with the rest of the config files
    }
    $rewrites = array();//list of all rewrites

    foreach ($configFiles as $file){
        $dom = new DOMDocument;
        $dom->loadXML(file_get_contents($file));
        $xpath = new DOMXPath($dom);
            $path = '//rewrite/*';//search for tags named 'rewrite'
            $text = $xpath->query($path);
            foreach ($text as $rewriteElement){
                $type = $rewriteElement->parentNode->parentNode->parentNode->tagName;//what is overwritten (model, block, helper)
                $parent = $rewriteElement->parentNode->parentNode->tagName;//module identifier that is being rewritten (core, catalog, sales, ...)
                $name = $rewriteElement->tagName;//element that is rewritten (layout, product, category, order)
                foreach ($rewriteElement->childNodes as $element){
                    $rewrites[$type][$parent.'/'.$name][] = $element->textContent;//class that rewrites it
                }
            }
    }
    echo "<pre>";print_r($rewrites);
  ?>

Output is

Array
  (
   [models] => Array
    (
        [cataloginventory/stock_item_api_v2] => Array
            (
                [0] => Example_Webservices_Model_Cataloginventory_Api_V2
            )

        [sales/order_api] => Array
            (
                [0] => Example_Webservices_Model_Order_Api
            )

        [core_mysql4/session] => Array
            (
                [0] => Cm_RedisSession_Model_Session
            )

    )

)

The script is:

config.xml:

<?xml version="1.0"?>
<config>
<modules>
    <Example_Webservices>
        <version>0.2.0</version>
    </Example_Webservices>
</modules>

<frontend>
    <routers>
      <connector>
        <use>standard</use>
          <args>
            <module>Example_Webservices</module>
            <frontName>test</frontName>
          </args>
      </connector>
    </routers>
 </frontend>

<global>
    <models>
         <cataloginventory>
             <rewrite>
                 <stock_item_api_v2>Example_Webservices_Model_Cataloginventory_Api_V2</stock_item_api_v2>
             </rewrite>
         </cataloginventory>
        <sales>
            <rewrite>
                <order_api>Example_Webservices_Model_Order_Api</order_api>
            </rewrite>
        </sales>
    </models>
</global>

Example/Webservices/Model/Order/Api.php file:

<?php

  class Example_Webservices_Model_Order_Api extends Mage_Sales_Model_Order_Api {
  protected function _initOrder($orderIncrementId) {
    $order = Mage::getModel('sales/order');

    if(is_string($orderIncrementId)) {
        $order->loadByIncrementId($orderIncrementId);
        if (!$order->getId()) {
            $this->_fault('not_exists');
        }
    } else {
        $order->load($orderIncrementId);
        if (!$order->getId()) {
            $this->_fault('not_exists');
        }
    }
    return $order;
}

public function cancel($orderIncrementId)
{
    Mage::log("Canel Order",null,'cancel-order.log');
    $order = $this->_initOrder($orderIncrementId);

    if (Mage_Sales_Model_Order::STATE_CANCELED == $order->getState()) {
        $this->_fault('status_not_changed');
    }
    try {
        $order->cancel();
        $order->save();
    } catch (Mage_Core_Exception $e) {
        $this->_fault('status_not_changed', $e->getMessage());
    }
    if (Mage_Sales_Model_Order::STATE_CANCELED != $order->getState()) {
        $this->_fault('status_not_changed');
    }
    return true;
  }
}

Answer 1

I'm just speculating here but I think you are using the Api V2 version and that's why you end up in the original order api class.
For v2 api the class that is used is Mage_Sales_Model_Order_Api_V2 that extends Mage_Sales_Model_Order_Api.
So your new class is never used. And the V2 class is still extending the old class.

What you need to do is to rewrite the v2 class also.
In your config.xml file, inside the sales->rewrite tag add this also

<order_api_v2>Example_Webservices_Model_Order_Api_V2</order_api_v2>

and create the file Example/Webservices/Model/Order/Api/V2.php with this content

<?php
class Example_Webservices_Model_Order_Api_V2 extends Example_Webservices_Model_Order_Api
{
}

Now you should be covered for both api v1 and v2.

Answer 2

Why dont you just copy the file in this location. You dont even need a rewrite.

app/code/local/Mage/Sales/Model/Order/Api.php

Now you can override any function.