wpcraft

Forms is the perfect solution for any wordpress website which needs more flexible forms.
Forms for contact page, CTA and landing page based on WordPress.
<ul>
<li>Insert form as shortcode</li>
<li>Create form template as post type</li>
<li>Save data as post and send to email.</li>
</ul>
<h4>Website</h4>
https://github.com/systemo-biz/forms-by-systemo
<h4>Documentation</h4>
https://github.com/systemo-biz/forms-by-systemo/wiki

Forms by Systemo

Fully customise WordPress forms with powerful shortcodes.

digitalpoint

The Shortcode Callback plugin allows you to use a [callback] shortcode to execute arbitrary PHP code wherever the shortcode is used.
Usage
Execute someFunction() and insert whatever it returns with the following shortcode: 
 [callback function=”someFunction”]
Example shortcode to include a PHP file (the path is relative to WordPress’ ABSPATH), then insert the results of someFunction() where you used the shortcode: 
 [callback include=”custom/filetoinclude.php” function=”someFunction”]
Shortcode example that includes a PHP file (the path is relative to WordPress’ ABSPATH), then passes a paramter to someFunction() and returns the results where you used the shortcode: 
 [callback function=”someFunction” include=”custom/filetoinclude.php” param=”something”]
The format to call a class/method with the shortcode is exactly the same as above, except you specify the class::method in the “function” attribute of the shortcode. 
 [callback function=”someClass::someFunction” include=”custom/filetoinclude.php” param=”something”]
There is an example (with PHP code) <a href="https://wordpress.org/plugins/shortcode-callback/faq/" rel="ugc">over here</a>.

Shortcode Callback

Adds a [callback] shortcode that can trigger PHP code so you can insert custom/complex things into your pages/posts.

Forms by Systemo vs Shortcode Callback