handle case where all columns are excluded

Author: contactashish13

classes/Visualizer/Module/Chart.php

@@ -690,6 +690,7 @@ private function _handleDataAndSettingsPage() {
 					'invalid_source' => esc_html__( 'You have entered invalid URL. Please, insert proper URL.', 'visualizer' ),
 					'loading'       => esc_html__( 'Loading...', 'visualizer' ),
 					'json_error'    => esc_html__( 'An error occured in fetching data.', 'visualizer' ),
+					'select_columns'    => esc_html__( 'Please select a few columns to include in the chart.', 'visualizer' ),
 				),
 				'charts' => array(
 					'canvas' => $data,

classes/Visualizer/Render/Layout.php

@@ -408,7 +408,7 @@ public static function _renderEditorTable( $args ) {
 				echo '<select name="type[]">';
 			} else {
 				echo '<input name="header[]" type="hidden" value="' . $header . '">';
-				echo '<select name="type[' . $header . ']">';
+				echo '<select name="type[' . $header . ']"  class="viz-select-data-type">';
 			}
 			echo '<option value="" title="' . __( 'Exclude from chart', 'visualizer' ) . '">' . __( 'Exclude', 'visualizer' ) . '</option>';
 			echo '<option value="0" disabled title="' . __( 'Include in chart and select data type', 'visualizer' ) . '">--' . __( 'OR', 'visualizer' ) . '--</option>';

classes/Visualizer/Render/Page/Data.php

@@ -222,7 +222,7 @@ class="visualizer-select">
 													?>
 											</div>
 
-											<p class="viz-group-description viz-info-msg"><?php echo sprintf( __( 'Please make sure you click \'Save & Show Chart\' on the left before you click \'Show Chart\' below.', 'visualizer' ) ); ?></p>
+											<p class="viz-group-description viz-info-msg json-chart-msg" style="display: none"><?php echo sprintf( __( 'Please make sure you click \'Save & Show Chart\' on the left before you click \'Show Chart\' below.', 'visualizer' ) ); ?></p>
 											<input type="button" id="json-chart-button" class="button button-secondary show-chart-toggle"
 											value="<?php echo $bttn_label; ?>" data-current="chart"
 											data-t-filter="<?php _e( 'Show Chart', 'visualizer' ); ?>"

js/frame.js

@@ -385,6 +385,7 @@
                 $(this).attr( 'data-current', 'filter' );
                 $( '.visualizer-editor-lhs' ).hide();
                 $( '#visualizer-json-screen' ).css("z-index", "9999").show();
+                $('.json-chart-msg').show();
                 $( '#canvas' ).hide();
             }else{
                 var filter_button = $(this);
@@ -393,6 +394,7 @@
                 filter_button.val( filter_button.attr( 'data-t-chart' ) );
                 filter_button.html( filter_button.attr( 'data-t-chart' ) );
                 filter_button.attr( 'data-current', 'chart' );
+                $('.json-chart-msg').hide();
                 $( '#canvas' ).css("z-index", "1").show();
                 $('#canvas').unlock();
             }
@@ -476,6 +478,17 @@
 
         // when the data is set and the chart is updated, toggle the screen so that the chart is shown
         $('#json-conclude-form').on( 'submit', function(e){
+            // at least one column has to be selected as non-excluded.
+            var count_selected = 0;
+            $('select.viz-select-data-type').each(function(i, element){
+                if($(element).prop('selectedIndex') > 0){
+                    count_selected++;
+                }
+            });
+            if(count_selected === 0){
+                alert(visualizer.l10n.select_columns);
+                return false;
+            }
             // populate the form elements that are in the other tabs.
             $('#json-conclude-form-helper .json-form-element, #json-endpoint-form .json-form-element, #json-root-form .json-form-element').each(function(x, y){
                 $('#json-conclude-form').append('<input type="hidden" name="' + y.name + '" value="' + y.value + '">');