Merge pull request #1810 from edx/anton/fix-math-operations-in-numerical-input

Fix Numerical input to support mathematical operations.

CHANGELOG.rst

@@ -5,6 +5,8 @@ These are notable changes in edx-platform.  This is a rolling list of changes,
 in roughly chronological order, most recent first.  Add your entries at or near
 the top.  Include a label indicating the component affected.
 
+Blades: Fix Numerical input to support mathematical operations. BLD-525.
+
 Blades: Improve calculator's tooltip accessibility. Add possibility to navigate
   through the hints via arrow keys. BLD-533.
 

common/lib/xmodule/xmodule/js/spec/problem/edit_spec.coffee

@@ -100,7 +100,7 @@ describe 'MarkdownEditingDescriptor', ->
         = 3.14159 +- .02
 
         Enter the approximate value of 502*9:
-        = 4518 +- 15%
+        = 502*9 +- 15%
 
         Enter the number of fingers on a human hand:
         = 5
@@ -125,7 +125,7 @@ describe 'MarkdownEditingDescriptor', ->
         </numericalresponse>
 
         <p>Enter the approximate value of 502*9:</p>
-        <numericalresponse answer="4518">
+        <numericalresponse answer="502*9">
           <responseparam type="tolerance" default="15%" />
           <formulaequationinput />
         </numericalresponse>

common/lib/xmodule/xmodule/js/src/problem/edit.coffee

@@ -234,12 +234,15 @@ class @MarkdownEditingDescriptor extends XModule.Descriptor
             floatValue = parseFloat(answersList[0]);
 
         if(!isNaN(floatValue)) {
-          var params = /(.*?)\+\-\s*(.*?$)/.exec(answersList[0]);
+          // Tries to extract parameters from string like 'expr +- tolerance'
+          var params = /(.*?)\+\-\s*(.*?$)/.exec(answersList[0]),
+              answer = answersList[0].replace(/\s+/g, '');
           if(params) {
-            string = '<numericalresponse answer="' + floatValue + '">\n';
+            answer = params[1].replace(/\s+/g, '');
+            string = '<numericalresponse answer="' + answer + '">\n';
             string += '  <responseparam type="tolerance" default="' + params[2] + '" />\n';
           } else {
-            string = '<numericalresponse answer="' + floatValue + '">\n';
+            string = '<numericalresponse answer="' + answer + '">\n';
           }
           string += '  <formulaequationinput />\n';
           string += '</numericalresponse>\n\n';