Paypal Express integration (OpenCart Mod)

DEMO - This site uses the Paypal Express payment option. Simply use it to checkout to see it working live!

Supported OpenCart Versions:
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v1.3.0, v1.3.1, v1.3.2, v1.3.3, v1.3.4, v1.4.0, v1.4.4, v1.4.6, v1.4.7, v1.4.8, v1.4.9


What does it do:
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This contrib adds support for Paypal Express payment integration. This allows customers to checkout from any page, login to paypal's site to authorize payment, then get sent back to your store to complete the checkout process, Bypassing the address entry.


Requirements:
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  * You will of course need to have a Free Paypal Business or Free Premiere Personal account as that is required to use Paypal Express.


Main features:
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  * No more Lost IPN/Lost order problems!
  * No file modifications!
  * Debug Mode option (log or mail)
  * Works with Guest & Logged in customers
  * Allows for editing the shipping address before final checkout.
  * Sandbox mode Support
  * Supported Currencies check and auto-convert
  * Includes Express Checkout sidebox to allow checkout from any page.
  * Only shown when cart total is greater than 0.00
  * Intelligent code self-handles many error scenarios in the process
  * Checkout can be done at any point in the store
  * More Features: http://www.lexiconn.com/blog/2010/04/ditch-paypal-standard-for-paypal-express/


How to install it:
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1) Unzip and upload the contents of the upload folder to the root directory of your OpenCart installation.
2) From the admin menu, go to 'Admin->Users->User Groups'. Edit Top Administrator
3) Find and check the entries for any unchecked files in both modify and access. save.
4) From the admin menu, go to 'Extensions->Payment'.
5) Install the new module, and click edit to configure.


Troubleshooting:
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1. Getting "10002 : Security Header Not Valid" error. This means you are trying to use sandbox mode with a live account or vice versa. Be sure you set Sandbox to "no" for live accounts and "yes" for sandbox/test accounts
2. Connection redirection errors. This happens if the code is somehow in an infinite loop. There should be no cases of this, but if you see this error in firefox, then please request support.
3. Shipping Address doesn't match the paypal address. The logic is, if a customer has logged in and already chosen shipping, then when using paypal express to checkout, the code does not replace the customer's pre-selected shipping address. This is meant as a feature so that if a customer is trying to ship somewhere else, then he won't have to re-edit his shipping address because it was overwritten by the paypal address. If the customer has not chosen a shipping method yet, then the shipping address will use the paypal address.