Need to override Flatrate.php

Question

How can i override vendor/magento/module-offline-shipping/Model/Carrier/Flatrate.php file as i need to add

 if($request->getSubtotalIncludingTax() > 25){
         return false;
    }

code so that if my cart value is > 25 then hide flatrate shipping method

Inside function collectRates(RateRequest $request)

Answer 1

etc\di.xml

     <config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">
        <type name="Magento\OfflineShipping\Model\Carrier\Flatrate">
    <plugin name="Vendor_Module_Plugin" type="Vendor\Module\Plugin\OfflinePlugin" sortOrder="10" disabled="false"  />
</type>

Vendor\Module\Plugin\OfflinePlugin.php

     <?php

        namespace Vendor\Module\Plugin;

        class OfflinePlugin
        {

           public function 
           aftercollectRates(\Magento\OfflineShipping\Model\Carrier\Flatrate $subject, $result)
          {

           //set your logic here

           }

}

Note: Don't use preference as per magento coding standard

Answer 2

You Can Override File And Change As Per Your Requirment :-

etc/di.xml

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">    
    <preference for="Magento\OfflineShipping\Model\Carrier\Flatrate" type="Namespace\Module\Model\OfflineShipping\Carrier\Override\FlatrateOverride" />
</config>

Answer 3

In order to override, you just need to add Flatrate.php in your custom module

Path should be like: app/code/Yourpackage/Yourmodule/Model/Carrier/Flatrate.php

Add whatever you want in above path file

if($request->getSubtotalIncludingTax() > 25){
         return false;
}

You need to add di.xml in your module

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">    
    <preference for="Magento\OfflineShipping\Model\Carrier\Flatrate" type="Yourpackage\Yourmodule\Model\Carrier\Flatrate" />
</config>

I hope this will help