We have stopped using legacy WHMCS-WP technique for our WHMCS-WP integration products. Proxy-based legacy integration technique that was used by us (and other competing products are still using the same) was an off the road technique yet proven technique to work with older versions of WHMCS. It was based on proxy mechanism.
What is Legacy WHMCS-WP Integration Technique?
In this method, the plugin acts as a special proxy in between WHMCS and client. It fetches “Client Area” from WHMCS, modifies it to fit in WordPress and pass it on to Client. It does so by using its PHP based file server. In the process of relaying information between original WHMCS and end user, it will
a. change HTML
c. Rewrite cookies
One major limitation of this technique proxy needs to be reprogrammed whenever the output of HTML WHMCS/CSS of (even if underneath functions are still same). It results in users waiting for a new update whenever WHMCS make any changes.
It is less secure as compared to API.
It Is not a systematic approach.
API based integration technique
In API Access only data is fetched from WHMCS, HTML/CSS is totally generated in WordPress. Hence WHMCS Client Area Plugin uses its own template to generate HTML/CSS which is very close to six template. It can be styled using custom CSS just like any other WordPress plugin to match with your theme.
It is easier to match with your WP theme.
It is more secure, in line with WHMCS guidelines and makes use of new programming techniques.
Above all, your WHMCS integrations will keep working uninterrupted when you upgrade your WHMCS.
It is modular, and you get as much integration as you want.
It offers easy styling of WHMCS client area.
Features that are missing in the initial release but we intend to include in coming releases
Users may need to click close button after paying invoice
*upgrade/downgrade for configurable options
* Manage CreditCards
Only features available through WHMCS API are supported (Third party plugins are not supported)
It is our intention to make this as complete as possible through latest programming techniques. The above list will keep shirking with every coming release.