Render: Add options to the Logic shortcode.

add_to_logic.php

<?php
/**
 * First, we need to actually add our new options to each selectbox.
 */
add_filter( 'render_att_pre_loop', function( $atts, $code ) {
  
  // Make sure we only do this for the Logic shortcode
  if ( $code == 'render_logic' ) {
    
    // Here's an option for the first argument
    $atts['arg1']['properties']['options']['new_argument'] = __( 'New argument', 'Render_Extension' );
    
    // And the second
    $atts['arg2']['properties']['options']['new_argument_2'] = __( 'New argument 2', 'Render_Extension' );
    
    // And even a new operator!
    $atts['operator']['properties']['options']['new_operator'] = __( 'New operator', 'Render_Extension' );
  }
  
  // We have to return the new atts (or unmodified atts) back through
  return $atts;
}, 10, 2 ); // Very important to pass "2". This tells the filter to pass 2 arguments through (in this case, $atts and $code)

/**
 * Next we need to filter the argument coming through the actual shortcode callback.
 */ 
add_filter( 'render_sc_logic_arg1', function( $argument_1, $atts ) {
  
  // Test our argument 1 against NEW argument(s)
  switch ( $atts['arg1'] ) {
    case ('new_argument'):
      
      // Obviously the way we figure out what to return is totaly up to whatever the use-case is
      return some_special_function_or_something();
      break;
    default:
      
      // It's very important to have a default of simply passingn the argument_1 result back through (for if the user does NOT select our new argument)
      return $argument_1;
  }
}, 10, 2 );

/**
 * Here we're doing the exact same thing as with argument 1.
 */ 
add_filter( 'render_sc_logic_arg2', function( $argument_2, $atts ) {
  
  switch ( $atts['arg2'] ) {
    case ('new_argument'):
      return some_other_special_function_or_something( isset( $atts['parameter'] ) ? $atts['parameter'] : '' );
      break;
    default:
      return $argument_2;
  }
}, 10, 2 );

/**
 * If we added a new operator to the dropdown, we need to also check for that in the shortcode callback.
 */ 
add_filter( 'render_sc_logic_operator', function( $output, $content, $argument_1, $argument_2, $atts ) {
  
  // Switch through our new operator(s)
  switch ( $atts['operator'] ) {
    case ('new_operator'):
      
      // This is ALSO totally dependent on the use-case. Just compare the arguments in some sort of way.
      // We also need to make sure we return empty content back if the arguments did not pass.
      if ( $argument_1 {new_operator} $argument_2 ) {
        return $content;
      } else {
        return '';
      }
      break;
    default:
      
      // Again, very important to default to not modifying the original output
      return $output;
  }
}, 10, 5 );