Fix #289 - error when missing_is_zero is set and data length is 1

.gitignore

@@ -4,3 +4,5 @@ node_modules
 other/divider.psd
 
 other/htaccess.txt
+
+.DS_Store

dist/metricsgraphics.js

@@ -1765,7 +1765,12 @@
         if (!args) { args = {}; }
         args = merge_with_defaults(args, defaults);
 
-        //this is how we're dealing with passing in a single array of data, 
+        if (d3.select(args.target).empty()) {
+            console.warn('The specified target element "' + args.target + '" could not be found in the page. The chart will not be rendered.');
+            return;
+        }
+
+        //this is how we're dealing with passing in a single array of data,
         //but with the intention of using multiple values for multilines, etc.
 
         //do we have a time_series?
@@ -1854,16 +1859,16 @@
         chart_title(args);
 
         //draw axes
-        args.use_small_class = args.height - args.top - args.bottom - args.buffer 
-                <= args.small_height_threshold && args.width - args.left-args.right - args.buffer * 2 
+        args.use_small_class = args.height - args.top - args.bottom - args.buffer
+                <= args.small_height_threshold && args.width - args.left-args.right - args.buffer * 2
                 <= args.small_width_threshold || args.small_text;
 
         //if we're updating an existing chart and we have fewer lines than
         //before, remove the outdated lines, e.g. if we had 3 lines, and we're calling
         //data_graphic() on the same target with 2 lines, remove the 3rd line
         if(args.data.length < $(args.target).find('svg .mg-main-line').length) {
             //now, the thing is we can't just remove, say, line3 if we have a custom
-            //line-color map, instead, see which are the lines to be removed, and delete those    
+            //line-color map, instead, see which are the lines to be removed, and delete those
             if(args.custom_line_color_map.length > 0) {
                 var array_full_series = function(len) {
                     var arr = new Array(len);
@@ -1873,7 +1878,7 @@
 
                 //get an array of lines ids to remove
                 var lines_to_remove = arrDiff(
-                    array_full_series(args.max_data_size), 
+                    array_full_series(args.max_data_size),
                     args.custom_line_color_map);
 
                 for(var i=0; i<lines_to_remove.length; i++) {
@@ -4116,7 +4121,11 @@
                 : false;
 
         //are we replacing missing y values with zeros?
-        if (args.missing_is_zero && args.chart_type === 'line' && is_time_series) {
+        if (args.missing_is_zero
+                && args.chart_type === 'line'
+                && is_time_series
+                && args.data.length > 1
+            ) {
             for (var i = 0;i < args.data.length; i++) {
                 var first = args.data[i][0];
                 var last = args.data[i][args.data[i].length-1];

src/js/misc/process.js

@@ -61,7 +61,11 @@ function process_line(args) {
             : false;
 
     //are we replacing missing y values with zeros?
-    if (args.missing_is_zero && args.chart_type === 'line' && is_time_series) {
+    if (args.missing_is_zero
+            && args.chart_type === 'line'
+            && is_time_series
+            && args.data.length > 1
+        ) {
         for (var i = 0;i < args.data.length; i++) {
             var first = args.data[i][0];
             var last = args.data[i][args.data[i].length-1];

tests/misc/process_test.js

@@ -0,0 +1,14 @@
+module('process');
+
+test('args.missing_is_zero doesn\'t throw a "args.data[0][0] is undefined" error', function() {
+    var data = [{"date": new Date('2014-02-02'), "value": 6}];
+    var params = {
+        data: data,
+        target: "#qunit-fixture",
+        missing_is_zero: true
+    };
+
+    MG.data_graphic(params);
+
+    equal(params.data.length, 1, 'args.data is defined');
+});