add additional shape label template vars, exclude paths

Author: emilykl

src/components/shapes/draw.js

@@ -35,10 +35,24 @@ var FROM_TL = require('../../constants/alignment').FROM_TL;
 // if opt is blank, val can be 'add' or a full options object to add a new
 //  annotation at that point in the array, or 'remove' to delete this one
 
+var shapeLabelTemplateVars = {
+    x0: (function(shape) { return shape.x0; }),
+    x1: (function(shape) { return shape.x1; }),
+    y0: (function(shape) { return shape.y0; }),
+    y1: (function(shape) { return shape.y1; }),
+    slope: (function(shape) { return (shape.y1 - shape.y0) / (shape.x1 - shape.x0); }),
+    width: (function(shape) { return shape.x1 - shape.x0; }),
+    height: (function(shape) { return shape.y1 - shape.y0; }),
+    length: (function(shape) { return Math.sqrt(Math.pow((shape.x1 - shape.x0), 2) + Math.pow((shape.y1 - shape.y0), 2)); }),
+    xcenter: (function(shape) { return (shape.x1 - shape.x0) / 2; }),
+    ycenter: (function(shape) { return (shape.y1 - shape.y0) / 2; }),
+};
+
 module.exports = {
     draw: draw,
     drawOne: drawOne,
-    eraseActiveShape: eraseActiveShape
+    eraseActiveShape: eraseActiveShape,
+    shapeLabelTemplateVars: Object.keys(shapeLabelTemplateVars),
 };
 
 function draw(gd) {
@@ -611,16 +625,16 @@ function drawLabel(gd, index, options, shapeGroup) {
     // Text template overrides text
     var text = options.label.text;
     if(options.label.texttemplate) {
+        var templateValues = {};
+        if(options.type !== 'path') {
+            Object.keys(shapeLabelTemplateVars).forEach(function(key) {
+                templateValues[key] = shapeLabelTemplateVars[key](options);
+            });
+        }
         text = Lib.texttemplateStringForShapes(options.label.texttemplate,
             {},
             gd._fullLayout._d3locale,
-            {
-                x0: options.x0,
-                y0: options.y0,
-                x1: options.x1,
-                y1: options.y1,
-                slope: (options.y1 - options.y0) / (options.x1 - options.x0),
-            });
+            templateValues);
     }
 
     var labelGroupAttrs = {