Adds a z-score xpath calculation

This makes using z-score much more flexible than the widget
implementation.

#4457

static/js/enketo/OpenrosaXpathEvaluatorBinding.js

@@ -1,5 +1,7 @@
+var _ = require('underscore');
 var ExtendedXpathEvaluator = require('extended-xpath');
 var openrosa_xpath_extensions = require('openrosa-xpath-extensions');
+var medicExtensions = require('./medic-xpath-extensions');
 var translator = require('./translator');
 
 module.exports = function() {
@@ -12,6 +14,8 @@ module.exports = function() {
         return evaluator.createNSResolver.apply( evaluator, arguments );
     };
     this.xml.jsEvaluate = function(e, contextPath, namespaceResolver, resultType, result) {
+        var extensions = openrosa_xpath_extensions(translator.t);
+        extensions.func = _.extend(extensions.func, medicExtensions.func);
         var evaluator = new ExtendedXpathEvaluator(
                 function wrappedXpathEvaluator(v) {
                     // Node requests (i.e. result types greater than 3 (BOOLEAN)
@@ -23,7 +27,7 @@ module.exports = function() {
                     var doc = contextPath.ownerDocument;
                     return doc.evaluate(v, contextPath, namespaceResolver, wrappedResultType, result);
                 },
-                openrosa_xpath_extensions(translator.t));
+                extensions);
         return evaluator.evaluate(e, contextPath, namespaceResolver, resultType, result);
     };
     window.JsXPathException =

static/js/enketo/medic-xpath-extensions.js

@@ -0,0 +1,16 @@
+var zscoreUtil;
+
+module.exports = {
+  init: function(_zscoreUtil) {
+    zscoreUtil = _zscoreUtil;
+  },
+  func: {
+    'z-score': function(chartId, sex, x, y) {
+      var result = zscoreUtil(chartId, sex, x, y);
+      if (!result) {
+          return { t: 'str', v: '' };
+      }
+      return { t: 'num', v: result };
+    }
+  }
+};

static/js/enketo/widgets/z-score.js

@@ -48,27 +48,27 @@ define( function( require, exports, module ) {
     };
 
     ZScoreWidget.prototype._update = function(self) {
-        var options = {
-            sex: self.group.find( '.or-appearance-zscore-sex [data-checked=true] input' ).val(),
-            age: self.group.find( '.or-appearance-zscore-age input' ).val(),
-            weight: self.group.find( '.or-appearance-zscore-weight input' ).val(),
-            height: self.group.find( '.or-appearance-zscore-height input' ).val()
-        };
-        self.zScoreService(options)
-            .then(function(scores) {
-                self.group.find('.or-appearance-zscore-weight-for-age input')
-                          .val(self._round(scores.weightForAge))
-                          .trigger( 'change' );
-                self.group.find('.or-appearance-zscore-height-for-age input')
-                          .val(self._round(scores.heightForAge))
-                          .trigger( 'change' );
-                self.group.find('.or-appearance-zscore-weight-for-height input')
-                          .val(self._round(scores.weightForHeight))
-                          .trigger( 'change' );
-            })
-            .catch(function(err) {
-                self.logService.error('Error calculating z-score', err);
-            });
+        var sex = self.group.find( '.or-appearance-zscore-sex [data-checked=true] input' ).val();
+        var age = self.group.find( '.or-appearance-zscore-age input' ).val();
+        var weight = self.group.find( '.or-appearance-zscore-weight input' ).val();
+        var height = self.group.find( '.or-appearance-zscore-height input' ).val();
+        self.zScoreService().then(function(util) {
+            var wfa = util('weight-for-age', sex, age, weight);
+            self.group.find('.or-appearance-zscore-weight-for-age input')
+                      .val(self._round(wfa))
+                      .trigger( 'change' );
+            var hfa = util('height-for-age', sex, age, height);
+            self.group.find('.or-appearance-zscore-height-for-age input')
+                      .val(self._round(hfa))
+                      .trigger( 'change' );
+            var wfh = util('weight-for-height', sex, height, weight);
+            self.group.find('.or-appearance-zscore-weight-for-height input')
+                      .val(self._round(wfh))
+                      .trigger( 'change' );
+        })
+        .catch(function(err) {
+            self.logService.error('Error calculating z-score', err);
+        });
     };
 
     ZScoreWidget.prototype.destroy = function( /* element */ ) {};

static/js/services/enketo.js

@@ -1,6 +1,7 @@
 var uuid = require('uuid/v4'),
     pojo2xml = require('pojo2xml'),
-    xpathPath = require('../modules/xpath-element-path');
+    xpathPath = require('../modules/xpath-element-path'),
+    medicXpathExtensions = require('../enketo/medic-xpath-extensions');
 
 /* globals EnketoForm */
 angular.module('inboxServices').service('Enketo',
@@ -22,7 +23,8 @@ angular.module('inboxServices').service('Enketo',
     TranslateFrom,
     UserContact,
     XmlForm,
-    XSLT
+    XSLT,
+    ZScore
   ) {
     'use strict';
     'ngInject';
@@ -32,6 +34,17 @@ angular.module('inboxServices').service('Enketo',
     var FORM_ATTACHMENT_NAME = 'xml';
     var REPORT_ATTACHMENT_NAME = this.REPORT_ATTACHMENT_NAME = 'content';
 
+    var init = function() {
+      ZScore()
+        .then(function(zscoreUtil) {
+          medicXpathExtensions.init(zscoreUtil);
+        })
+        .catch(function(err) {
+          $log.error('Error initialising zscore util', err);
+        });
+    };
+    var inited = init();
+
     var replaceJavarosaMediaWithLoaders = function(id, form) {
       form.find('img,video,audio').each(function() {
         var elem = $(this);
@@ -324,18 +337,17 @@ angular.module('inboxServices').service('Enketo',
     };
 
     this.render = function(selector, id, instanceData, editedListener) {
-      return getUserContact()
-        .then(function() {
-          return renderForm(selector, id, instanceData, editedListener);
-        });
+      return $q.all([inited, getUserContact()]).then(function() {
+        return renderForm(selector, id, instanceData, editedListener);
+      });
     };
 
     this.renderContactForm = renderForm;
 
     this.renderFromXmlString = function(selector, xmlString, instanceData, editedListener) {
-      return Language()
-        .then(function(language) {
-          return translateXml(xmlString, language);
+      return $q.all([inited, Language()])
+        .then(function(results) {
+          return translateXml(xmlString, results[1]);
         })
         .then(transformXml)
         .then(function(doc) {

static/js/services/z-score.js

@@ -1,5 +1,7 @@
 angular.module('inboxServices').factory('ZScore',
   function(
+    $log,
+    Changes,
     DB
   ) {
 
@@ -9,44 +11,17 @@ angular.module('inboxServices').factory('ZScore',
     var CONFIGURATION_DOC_ID = 'zscore-charts';
     var MINIMUM_Z_SCORE = -4;
     var MAXIMUM_Z_SCORE = 4;
-    var CONFIGURATIONS = [
-      {
-        id: 'weight-for-age',
-        property: 'weightForAge',
-        required: [ 'sex', 'age', 'weight' ],
-        xAxis: 'age',
-        yAxis: 'weight'
-      },
-      {
-        id: 'height-for-age',
-        property: 'heightForAge',
-        required: [ 'sex', 'age', 'height' ],
-        xAxis: 'age',
-        yAxis: 'height'
-      },
-      {
-        id: 'weight-for-height',
-        property: 'weightForHeight',
-        required: [ 'sex', 'height', 'weight' ],
-        xAxis: 'height',
-        yAxis: 'weight'
-      }
-    ];
 
-    var findChart = function(charts, id) {
-      for (var i = 0; i < charts.length; i++) {
-        if (charts[i].id === id) {
-          return charts[i];
+    var tables;
+
+    var findTable = function(id) {
+      for (var i = 0; i < tables.length; i++) {
+        if (tables[i].id === id) {
+          return tables[i];
         }
       }
     };
 
-    var hasRequiredOptions = function(configuration, options) {
-      return configuration.required.every(function(required) {
-        return !!options[required];
-      });
-    };
-
     var findClosestDataSet = function(data, key) {
       if (key < data[0].key || key > data[data.length - 1].key) {
         // the key isn't covered by the configured data points
@@ -85,45 +60,66 @@ angular.module('inboxServices').factory('ZScore',
       return lowerIndex + MINIMUM_Z_SCORE + ratio;
     };
 
-    var calculate = function(configuration, charts, options) {
-      if (!hasRequiredOptions(configuration, options)) {
-        return;
-      }
-      var chart = findChart(charts, configuration.id);
-      if (!chart) {
-        // no chart configured in the database
-        return;
-      }
-      var sexData = chart.data[options.sex];
-      if (!sexData) {
-        // no data for the given sex
-        return;
-      }
-      var xAxisData = findClosestDataSet(sexData, options[configuration.xAxis]);
+    var calculate = function(data, x, y) {
+      var xAxisData = findClosestDataSet(data, x);
       if (!xAxisData) {
         // the key lies outside of the lookup table range
         return;
       }
-      return findZScore(xAxisData, options[configuration.yAxis]);
+      return findZScore(xAxisData, y);
     };
 
-    return function(options) {
-      options = options || {};
+    var init = function() {
       return DB().get(CONFIGURATION_DOC_ID)
         .then(function(doc) {
-          var result = {};
-          CONFIGURATIONS.forEach(function(configuration) {
-            result[configuration.property] = calculate(configuration, doc.charts, options);
-          });
-          return result;
+          tables = doc.charts;
         })
         .catch(function(err) {
           if (err.status === 404) {
-            throw new Error('zscore-charts doc not found');
+            return;
           }
           throw err;
         });
     };
+
+    Changes({
+      key: 'zscore-service',
+      filter: function(change) {
+        return change.id === CONFIGURATION_DOC_ID;
+      },
+      callback: function(change) {
+        tables = change.doc && change.doc.charts;
+      }
+    });
+
+    return function() {
+      return init().then(function() {
+        return function(tableId, sex, x, y) {
+          if (!tables) {
+            // log an error if the z-score utility is used but not configured
+            $log.error('Doc "' + CONFIGURATION_DOC_ID + '" not found');
+            return;
+          }
+          if (!sex || !x || !y) {
+            // the form may not have been filled out yet
+            return;
+          }
+          var table = findTable(tableId);
+          if (!table) {
+            // log an error if the z-score utility is used but not configured
+            $log.error('Requested z-score table not found', tableId);
+            return;
+          }
+          var data = table.data[sex];
+          if (!data) {
+            $log.error('The ' + tableId + ' z-score table is not configured for ' + sex + ' children');
+            // no data for the given sex
+            return;
+          }
+          return calculate(data, x, y);
+        };
+      });
+    };
   }
 
 );

tests/karma/unit/controllers/inbox.js

@@ -66,6 +66,7 @@ describe('InboxCtrl controller', () => {
       $provide.value('UserSettings', sinon.stub());
       $provide.value('Tour', { getTours: () => Promise.resolve([]) });
       $provide.value('RulesEngine', { init: KarmaUtils.nullPromise()() });
+      $provide.value('Enketo', sinon.stub());
       $provide.constant('APP_CONFIG', {
         name: 'name',
         version: 'version'

tests/karma/unit/services/enketo.js

@@ -123,6 +123,7 @@ describe('Enketo service', function() {
       $provide.value('EnketoPrepopulationData', EnketoPrepopulationData);
       $provide.value('AddAttachment', AddAttachment);
       $provide.value('XmlForm', XmlForm);
+      $provide.value('ZScore', () => Promise.resolve(sinon.stub()));
       $provide.value('$q', Q); // bypass $q so we don't have to digest
     });
     inject(function(_Enketo_) {