dynamic-params.php

<?php
/**
 * This is the ID of the select field that will set the min/max values
 */
function demo_minmax_get_colour_field_id() {
	return 1158; // Change this ID number
}

/**
 * This is the ID of the number field that has dynamic min and max values
 */
function demo_minmax_get_width_field_id() {
	return 1159; // Change this ID number
}

/**
 * Add new columns for min / max values
 */
function demo_minmax_add_extra_params( $option_count, $group_id, $item_key, $item, $key ) {
	
	if( isset( $item['field_id'] ) && $item['field_id'] == demo_minmax_get_colour_field_id() ) {
		$name = '_product_extra_groups_' . esc_attr( $group_id ) . '_' . esc_attr( $item_key ) . '[field_options][' . esc_attr( $option_count ) . ']';
		$min_width = isset( $item['field_options'][esc_attr( $key )]['min_width'] ) ? $item['field_options'][esc_attr( $key )]['min_width'] : '';
		$max_width = isset( $item['field_options'][esc_attr( $key )]['max_width'] ) ? $item['field_options'][esc_attr( $key )]['max_width'] : ''; ?>
		<td class="pewc-option-min_width pewc-option-extra">
			<input type="number" class="pewc-field-option-extra pewc-field-option-min_width" name="<?php echo $name; ?>[min_width]" value="<?php echo esc_attr( $min_width ); ?>">
		</td>
		<td class="pewc-option-max_width pewc-option-extra">
			<input type="number" class="pewc-field-option-extra pewc-field-option-max_width" name="<?php echo $name; ?>[max_width]" value="<?php echo esc_attr( $max_width ); ?>">
		</td>
	<?php }
	
}
add_action( 'pewc_after_option_params', 'demo_minmax_add_extra_params', 10, 5 );

/**
 * Add titles to the new columns
 */ 
function demo_minmax_add_extra_params_titles( $group_id, $item_key, $item ) {
	
	if( isset( $item['field_id'] ) && $item['field_id'] == demo_minmax_get_colour_field_id() ) {
		printf(
			'<th class="pewc-option-min_width pewc-option-extra-title"><div class="pewc-label">%s</div></th>',
			__( 'Min Width', 'pewc' )
		);
		printf(
			'<th class="pewc-option-max_width pewc-option-extra-title"><div class="pewc-label">%s</div></th>',
			__( 'Max Width', 'pewc' )
		);
	}

}
add_action( 'pewc_after_option_params_titles', 'demo_minmax_add_extra_params_titles', 10, 3 );

/**
 * Update the attributes on the front end
 */ 
function demo_minmax_option_attribute_string( $option_attribute_string, $item, $option_value, $option_index ) {
	
	if( isset( $item['field_id'] ) && $item['field_id'] == demo_minmax_get_colour_field_id() ) {

		$min_width = ! empty( $item['field_options'][$option_index]['min_width'] ) ? $item['field_options'][$option_index]['min_width'] : '';
		$max_width = ! empty( $item['field_options'][$option_index]['max_width'] ) ? $item['field_options'][$option_index]['max_width'] : '';

		$option_attribute_string .= " data-min-value='" . esc_attr( trim( $min_width ) ) . "'";
		$option_attribute_string .= " data-max-value='" . esc_attr( trim( $max_width ) ) . "'";
		error_log( $option_attribute_string );
		
	}
	
	return $option_attribute_string;
}
add_filter( 'pewc_option_attribute_string', 'demo_minmax_option_attribute_string', 10, 4 );

/**
 * Add custom JS on the product page
 */ 
function demo_minmax_js() {
	if( ! function_exists( 'is_product' ) || ! is_product() ) {
		return;
	} ?>
	<script>
		( function( $ ) {
			var minmax_update = {
				init: function() {
					$( 'body' ).on( 'change','.pewc-field-<?php echo demo_minmax_get_colour_field_id(); ?> select', this.reset_minmax );
					$( '.pewc-field-<?php echo demo_minmax_get_colour_field_id(); ?> select' ).trigger( 'change' );
				},
				reset_minmax: function() {
					// Update the min and max params on the number field
					var min_value = $( this ).find( ':selected' ).attr( 'data-min-value' );
					var max_value = $( this ).find( ':selected' ).attr( 'data-max-value' );
					
					var field_id = <?php echo demo_minmax_get_width_field_id(); ?>;
					
					$( '.pewc-field-' + field_id ).attr( 'data-field-minval', min_value );
					$( '.pewc-field-' + field_id + ' input' ).attr( 'min', min_value );
					
					$( '.pewc-field-' + field_id ).attr( 'data-field-maxval', max_value );
					$( '.pewc-field-' + field_id + ' input' ).attr( 'max', max_value );
				}
			}
			minmax_update.init();
		})( jQuery );
	</script>
	<?php
}
add_action( 'wp_footer', 'demo_minmax_js' );