My custom observer not working

Question

I am new in magento. I created a custom observer to trigger on the event sales_order_place_before, but its not working.

Here's my code: app/etc/modules/CustomPriceUpdate_Checkout.xml

<?xml version="1.0"?>
<config>
    <modules>
        <CustomPriceUpdate_Checkout>
            <codePool>local</codePool>
            <active>true</active>
            <depends>
                <Mage_Catalog />
            </depends>
        </CustomPriceUpdate_Checkout>
    </modules>
</config>

app/code/local/CustomPriceUpdate/Checkout/etc/config.xml

<?xml version="1.0" encoding="UTF-8"?>
<config>
<modules>
    <CustomPriceUpdate_Checkout>
        <version>0.0.1</version>
    </CustomPriceUpdate_Checkout>
</modules>
<global>
    <models>
        <myCustomPriceUpdate_Checkout>
            <class>CustomCheckout_Event_Model</class>
        </myCustomPriceUpdate_Checkout>
    </models>
    <events>
        <sales_order_place_before>
            <observers>
                <modify_product_price>
                    <type>singleton</type>
                    <class>myCustomPriceUpdate_Checkout/observer</class>
                    <method>update_price</method>
                </modify_product_price>
            </observers>
        </sales_order_place_before>
    </events>
</global>
</config>

app/code/local/CustomPriceUpdate/Checkout/Model/Observer.php

<?php
class CustomCheckout_Event_Model_Observer{

  public function update_price($observer){
    Mage::log("Order is placed");
  }
}

When I check the system.log file, I am seeing following error:

Warning: include(CustomCheckout/Event/Model/Observer.php): failed to open stream: No such file or directory in /var/www/html/lib/Va$

Warning: include(): Failed opening 'CustomCheckout/Event/Model/Observer.php' for inclusion (include_path='/var/www/html/app/code/loc$

Can anyone please suggest, what's wrong in the code ?

Answer 1

Change this

    <myCustomPriceUpdate_Checkout>
        <class>CustomCheckout_Event_Model</class>
    </myCustomPriceUpdate_Checkout>

To this

    <myCustomPriceUpdate_Checkout>
        <class>CustomPriceUpdate_Checkout_Model</class>
    </myCustomPriceUpdate_Checkout>

Answer 2

Adding to @Marius answer change class name in your observer as shown below

<?php
class CustomPriceUpdate_Event_Model_Observer{

    public function update_price($observer){
       Mage::log("Order is placed");
 }
}

Answer 3

You model class reference is wrong here. You used CustomCheckout_Event_Model in your config.xml file. Instead of that, you need to use CustomCheckout_Checkout_Model.

So you need to change model definition like :

<myCustomPriceUpdate_Checkout>
    <class>CustomPriceUpdate_Checkout_Model</class>
</myCustomPriceUpdate_Checkout>