Refactored frontend for the rebaseline server.

gm/rebaseline_server/static/new/js/app.js

+'use strict';
+
+/**
+ * TODO (stephana@): This is still work in progress. 
+ * It does not offer the same functionality as the current version, but 
+ * will serve as the starting point for a new backend.
+ * It works with the current backend, but does not support rebaselining.
+ */
+
+/*
+ * Wrap everything into an IIFE to not polute the global namespace.
+ */
+(function () { 
+
+  // Declare app level module which contains everything of the current app.
+  // ui.bootstrap refers to directives defined in the AngularJS Bootstrap 
+  // UI package (http://angular-ui.github.io/bootstrap/).
+  var app = angular.module('rbtApp', ['ngRoute', 'ui.bootstrap']);
+
+  // Configure the different within app views.
+  app.config(['$routeProvider', function($routeProvider) {
+    $routeProvider.when('/', {templateUrl: 'partials/index-view.html', 
+                              controller: 'IndexCtrl'});
+    $routeProvider.when('/view', {templateUrl: 'partials/rebaseline-view.html',
+                                  controller: 'RebaselineCrtrl'});
+    $routeProvider.otherwise({redirectTo: '/'});
+  }]);
+
+
+  // Shared constants used here and in the markup. These are exported when
+  // when used by a controller.
+  var c = {
+    // view stats fo the HTML 
+    ST_LOADING: 1,
+    ST_STILL_LOADING: 2,
+    ST_READY: 3,
+
+    // column types

[jcgregorio, 2014/09/04 18:37:32]

Keep app comments full sentences.

[stephana, 2014/09/05 14:37:16]

Done.

+    COL_FILTER: 'filter',
+    COL_IMAGE: 'image',
+    COL_REGULAR: 'regular',
+
+    // different modes of rendering 

[jcgregorio, 2014/09/04 18:37:32]

So if this is only going to be used for the new stuff, we should only care about
DM, right?

[stephana, 2014/09/05 14:37:16]

Yes. This was added when it wasn't as clear to me that we are targeting 'dm'. I
removee as much as I could find of the gm specific code, but I will have to do
another sweep once the new backend is ready.

On 2014/09/04 18:37:32, jcgregorio wrote:

+    TARGET_GM: 'gm',
+    TARGET_SKP: 'skp',
+
+    // request params for target === 'gm'
+    RESULTS_ALL: 'all',
+    RESULTS_FAILURES: 'failures',
+
+    // filter types
+    FILTER_FREE_FORM: 'free_form',
+    FILTER_CHECK_BOX: 'checkbox',
+
+    // columns 
+    COL_BUGS: 'bugs',
+    COL_IGNORE_FAILURE: 'ignore-failure',
+    COL_REVIEWED_BY_HUMANS: 'reviewed-by-human',
+
+    // image column order  TODO (stephana@): needs to be driven by backend data.
+    IMG_COL_ORDER: [
+       {
+        key: 'imageA', 
+        urlField: ['imageAUrl']
+      },
+      {
+        key: 'imageB', 
+        urlField: ['imageBUrl']
+      },
+      {
+        key: 'whiteDiffs',
+        urlField: ['differenceData', 'whiteDiffUrl'],
+        percentField: ['differenceData', 'percentDifferingPixels'],
+        valueField: ['differenceData', 'numDifferingPixels']
+      },
+      {
+        key: 'diffs',
+        urlField: ['differenceData', 'diffUrl'],
+        percentField: ['differenceData', 'perceptualDifference'],
+        valueField: ['differenceData', 'maxDiffPerChannel']
+      }
+    ],
+
+    // Choice of availabe image size selection.
+    IMAGE_SIZES: [
+      100,
+      200,
+      400
+    ],
+
+    // Choice of available number of records selection.
+    MAX_RECORDS: [
+      '100', 
+      '200',
+      '300'
+    ]
+  };  // end constants 
+
+  /*
+   * Index Controller 
+   */
+  // TODO: remove $timeout
+  app.controller('IndexCtrl', ['$scope', '$timeout', 'dataService', 
+  function($scope, $timeout, dataService) {
+    // init the scope 
+    $scope.c = c;
+    $scope.state = c.ST_LOADING;
+    $scope.qStr = dataService.getQueryString;
+
+    // TODO (stephana): Remove and replace with index data generated by the 
+    // backend to reflect the current "known" image sets to compare.
+    $scope.allSKPs = [
+    {
+      params: {
+        setBSection: 'actual-results',
+        setASection: 'expected-results',
+        setBDir: 'gs://chromium-skia-skp-summaries/' + 
+                 'Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug',
+        setADir: 'repo:expectations/skp/' +
+                 'Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug'
+      },
+      title: 'expected vs actuals on ' +
+             'Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug'
+    }, 
+    {
+      params: {
+        setBSection: 'actual-results',
+        setASection: 'expected-results',
+        setBDir: 'gs://chromium-skia-skp-summaries/' +
+                 'Test-Ubuntu12-ShuttleA-GTX660-x86-Release',
+        setADir: 'repo:expectations/skp/'+
+                 'Test-Ubuntu12-ShuttleA-GTX660-x86-Release'
+      },
+      title: 'expected vs actuals on Test-Ubuntu12-ShuttleA-GTX660-x86-Release'
+    },
+    {
+      params: {
+        setBSection: 'actual-results',
+        setASection: 'actual-results',
+        setBDir: 'gs://chromium-skia-skp-summaries/' + 
+                 'Test-Ubuntu12-ShuttleA-GTX660-x86-Release',
+        setADir: 'gs://chromium-skia-skp-summaries/' + 
+                 'Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug'
+      },
+      title: 'Actuals on Test-Mac10.8-MacMini4.1-GeForce320M-x86_64-Debug ' + 
+             'vs Test-Ubuntu12-ShuttleA-GTX660-x86-Release'
+    }
+    ];
+
+    // TODO (stephana): Remove this once we load index data from the server. 
+    $timeout(function () { 
+      $scope.state = c.ST_READY;
+    }); 
+  }]);
+
+  /* 
+   *  RebaselineCtrl
+   *  Controls the main comparison view.
+   *
+   *  @param {service} dataService Service that encapsulates functions to 
+   *                               retrieve data from the backend.
+   *  
+   */
+  app.controller('RebaselineCrtrl', ['$scope', '$timeout', 'dataService', 
+  function($scope, $timeout, dataService) {
+    // determine which to request
+    // TODO (stephana): This should be extracted from the query parameters.
+    var target = c.TARGET_GM;
+
+    // process the rquest arguments
+    // TODO (stephana): This should be determined from the query parameters.
+    var loadFn = dataService.loadAll;
+
+    // controller state variables 
+    var allData = null;
+    var filterFuncs = null;
+    var currentData = null;
+    var selectedData = null;
+
+    // Index of the column that should provide the sort key
+    var sortByIdx = 0;
+
+    // Sort in asending (true) or descending (false) order
+    var sortOrderAsc = true; 
+
+    // Array of functions for each column used for comparison during sort.
+    var compareFunctions = null;
+
+    // Variables to track load and render times
+    var startTime;
+    var loadStartTime;
+
+
+    /** Load the data from the backend **/ 
+    loadStartTime = Date.now();
+    function loadData() { 
+      loadFn().then(
+        function (serverData) {
+          $scope.header = serverData.header;
+          $scope.loadTime = Date.now() - loadStartTime;
+
+          // keep polling if the data are not ready yet
+          if ($scope.header.resultsStillLoading) {
+            $scope.state = c.ST_STILL_LOADING;
+            $timeout(loadData, 1000);
+            return;
+          }
+
+          // get the filter colunms and an array to hold filter data by user
+          var fcol = getFilterColumns(serverData);
+          $scope.filterCols = fcol[0];
+          $scope.filterVals = fcol[1];
+
+          // Add extra columns and retrieve the image columns
+          var otherCols = [ Column.regular(c.COL_BUGS) ];
+          var imageCols = getImageColumns(serverData);
+
+          // Concat to get all columns
+          // NOTE: The order is important since filters are rendered first, 
+          // followed by regular columns and images 
+          $scope.allCols = $scope.filterCols.concat(otherCols, imageCols);
+
+          // Pre-process the data and get the filter functions.
+          var dataFilters = getDataAndFilters(serverData, $scope.filterCols, 
+                                              otherCols, imageCols);
+          allData = dataFilters[0];
+          filterFuncs = dataFilters[1];
+
+          // Get regular columns (== not image columns)
+          var regularCols = $scope.filterCols.concat(otherCols);
+
+          // Get the compare functions for regular and image columns. These
+          // are then used to sort by the respective columns. 
+          compareFunctions = DataRow.getCompareFunctions(regularCols, 
+                                                         imageCols);
+
+          // Filter and sort the results to get them ready for rendering
+          updateResults();
+
+          // Data are ready for display
+          $scope.state = c.ST_READY;
+        },
+        function (httpErrResponse) {
+          console.log(httpErrResponse);        
+        });
+    };
+
+    /*
+     * updateResults
+     * Central render function. Everytime settings/filters/etc. changed
+     * this function is called to filter, sort and splice the data. 
+     *
+     * NOTE (stephana): There is room for improvement here: before filtering
+     * and sorting we could check if this is necessary. But this has not been
+     * a bottleneck so far. 
+     */
+    function updateResults () {
+      // run digest before we update the results. This allows
+      // updateResults to be called from functions trigger by ngChange
+      $scope.updating = true;
+      startTime = Date.now();
+
+      // delay by one render cycle so it can be called via ng-change
+      $timeout(function() {
+        // filter data 
+        selectedData = filterData(allData, filterFuncs, $scope.filterVals);
+
+        // sort the selected data.
+        sortData(selectedData, compareFunctions, sortByIdx, sortOrderAsc);
+
+        // only conside the elements that we really need
+        var nRecords = $scope.settings.nRecords;
+        currentData = selectedData.slice(0, parseInt(nRecords));
+
+        DataRow.setRowspanValues(currentData, $scope.mergeIdenticalRows);
+
+        // update the scope with relevant data for rendering.
+        $scope.data = currentData;
+        $scope.totalRecords = allData.length;
+        $scope.showingRecords = currentData.length;
+        $scope.selectedRecords = selectedData.length;
+        $scope.updating = false;
+
+        // measure the filter time and total render time (via timeout).
+        $scope.filterTime = Date.now() - startTime;
+        $timeout(function() { 
+          $scope.renderTime = Date.now() - startTime;
+        });
+      });
+    };
+
+    /**
+     * Generate the style value to set the width of images. 
+     * 
+     * @param {Column} col Column that we are trying to render. 
+     * @param {int} paddingPx Number of padding pixels.
+     * @param {string} defaultVal Default value if not an image column.
+     *
+     * @return {string} Value to be used in ng-style element to set the width 
+     *                  of a image column.
+     **/
+    $scope.getImageWidthStyle = function (col, paddingPx, defaultVal) { 
+      var result = (col.ctype === c.COL_IMAGE) ? 
+                   ($scope.imageSize + paddingPx + 'px') : defaultVal;
+      return result;
+    };
+
+    /**
+     * Sets the column by which to sort the data. If called for the 
+     * currently sorted column it will cause the sort to toggle between
+     * ascending and descending. 
+     * 
+     * @param {int} colIdx Index of the column to use for sorting. 
+     **/
+    $scope.sortBy = function (colIdx) { 
+      if (sortByIdx === colIdx) { 
+        sortOrderAsc = !sortOrderAsc;
+      } else {
+        sortByIdx = colIdx;
+        sortOrderAsc = true;
+      }
+      updateResults();
+    };
+
+    /**
+     * Generate a CSS class based on whether the identified column is currently

[jcgregorio, 2014/09/04 18:37:32]

Is the CSS class also used to control the display?

[stephana, 2014/09/05 14:37:16]

Changed this comment to make it clearer how this will be used. Namely to draw
the little up/down arrow next to a column name if this column is the sort key.

On 2014/09/04 18:37:32, jcgregorio wrote:

+     * used for sorting the data.
+     * 
+     * @param {string} prefix Prefix of the classname to be generated. 
+     * @param {int} idx Index of the target column.
+     * @param {string} defaultVal Value to return if current column is not used
+     *                            for sorting. 
+     *
+     * @return {string} CSS class name that a combination of the prefix and 
+     *                  direction indicator ('asc' or 'desc') if the column is 
+     *                  used for sorting. Otherwise the defaultVal is returned.
+     **/
+    $scope.getSortedClass = function (prefix, idx, defaultVal) {
+      if (idx === sortByIdx) { 
+        return prefix + ((sortOrderAsc) ? 'asc' : 'desc');
+      }
+
+      return defaultVal; 
+    };
+
+    /**
+     * Checkbox to merge identical records has change. Force an update.
+     **/
+    $scope.mergeRowsChanged = function () {
+      updateResults();
+    }
+
+    /**
+     * Max number of records to display has changed. Force an update. 
+     **/
+    $scope.maxRecordsChanged = function () {
+      updateResults();
+    };
+
+    /**
+     * Filter settings changed. Force an update. 
+     **/
+    $scope.filtersChanged = function () { 
+      updateResults();
+    };
+
+    /**
+     * Sets all possible values of the specified values to the given value.
+     * That means all checkboxes are eiter selected or unselected.
+     * Then force an update.
+     * 
+     * @param {int} idx Index of the target filter column.
+     * @param {boolean} val Value to set the filter values to. 
+     *
+     **/
+    $scope.setFilterAll = function (idx, val) {
+      for(var i=0, len=$scope.filterVals[idx].length; i<len; i++) {
+        $scope.filterVals[idx][i] = val;
+      }
+      updateResults();
+    };
+
+    /**
+     * Toggle the values of a filter. This toggles all values in a 
+     * filter. 
+     * 
+     * @param {int} idx Index of the target filter column.
+     **/
+    $scope.setFilterToggle = function (idx) { 
+      for(var i=0, len=$scope.filterVals[idx].length; i<len; i++) {
+        $scope.filterVals[idx][i] = !$scope.filterVals[idx][i];
+      }
+      updateResults();
+    };
+
+    // ****************************************
+    // Initialize the scope.
+    // ****************************************
+
+    // Inject the constants into the scope and set the initial state. 
+    $scope.c = c;
+    $scope.state = c.ST_LOADING;
+
+    // Initial settings
+    $scope.settings = {
+      showThumbnails: true,
+      imageSize: c.IMAGE_SIZES[0],
+      nRecords: c.MAX_RECORDS[0],
+      mergeIdenticalRows: true
+    };
+
+    // Initial values for filters set in loadData()
+    $scope.filterVals = [];
+
+    // Information about records - set in loadData()
+    $scope.totalRecords = 0;
+    $scope.showingRecords = 0;
+    $scope.updating = false;
+
+    // Trigger the data loading. 
+    loadData();
+
+  }]);
+
+  // data structs to interface with markup and backend
+  /**
+   * Models a column. It aggregates attributes of all 
+   * columns types. Some might be empty. See convenience 
+   * factory methods below for different column types.
+   * 
+   * @param {string} key Uniquely identifies this columns
+   * @param {string} ctype Type of columns. Use COL_* constants. 
+   * @param {string} ctitle Human readable title of the column.
+   * @param {string} ftype Filter type. Use FILTER_* constants.
+   * @param {FilterOpt[]} foptions Filter options. For 'checkbox' filters this 
+                                   is used to render all the checkboxes. 
+                                   For freeform filters this is a list of all
+                                   available values. 
+   * @param {string} baseUrl Baseurl for image columns. All URLs are relative 
+                             to this.
+   *
+   * @return {Column} Instance of the Column class. 
+   **/
+  function Column(key, ctype, ctitle, ftype, foptions, baseUrl) { 
+    this.key = key; 
+    this.ctype = ctype;
+    this.ctitle = ctitle;
+    this.ftype = ftype;
+    this.foptions = foptions;
+    this.baseUrl = baseUrl;
+    this.foptionsArr = [];
+
+    // get the array of filter options for lookup in indexOfOptVal
+    if (this.foptions) {
+      for(var i=0, len=foptions.length; i<len; i++) {
+        this.foptionsArr.push(this.foptions[i].value);
+      }
+    }
+  }
+
+  /**
+   * Find the index of an value in a column with a fixed set
+   * of options. 
+   * 
+   * @param {string} optVal Value of the column.
+   *
+   * @return {int} Index of optVal in this column.
+   **/
+  Column.prototype.indexOfOptVal = function (optVal) {
+    return this.foptionsArr.indexOf(optVal);
+  };
+
+  /**
+   * Set filter options for this column.
+   * 
+   * @param {FilterOpt[]} foptions Possible values for this column. 
+   **/
+  Column.prototype.setFilterOptions = function (foptions) { 
+    this.foptions = foptions;
+  };
+
+  /**
+   * Factory function to create a filter column. Same args as Column()
+   **/
+  Column.filter = function(key, ctitle, ftype, foptions) { 
+    return new Column(key, c.COL_FILTER, ctitle || key, ftype, foptions); 
+  }
+
+  /**
+   * Factory function to create an image column. Same args as Column()
+   **/
+  Column.image = function (key, ctitle, baseUrl) { 
+    return new Column(key, c.COL_IMAGE, ctitle || key, null, null, baseUrl); 
+  };
+
+  /**
+   * Factory function to create a regular column. Same args as Column()
+   **/
+  Column.regular = function (key, ctitle) { 
+    return new Column(key, c.COL_REGULAR, ctitle || key); 
+  }; 
+
+  /**
+   * Helper class to wrap a single option in a filter. 
+   * 
+   * @param {string} value Option value. 
+   * @param {int} count Number of instances of this option in the dataset.
+   *
+   * @return {} Instance of FiltertOpt
+   **/
+  function FilterOpt(value, count) { 
+    this.value = value; 
+    this.count = count;
+  }
+
+  /**
+   * Container for a single row in the dataset.
+   * 
+   * @param {int} rowspan Number of rows (including this and following rows) 
+                          that have identical values. 
+   * @param {string[]} dataCols Values of the respective columns (combination
+                                of filter and regular columns)
+   * @param {ImgVal[]} imageCols Image meta data for the image columns.
+   *
+   * @return {DataRow} Instance of DataRow. 
+   **/
+  function DataRow(rowspan, dataCols, imageCols) { 
+    this.rowspan = rowspan;
+    this.dataCols = dataCols;
+    this.imageCols = imageCols;
+  }
+
+  /**
+   * Gets the comparator functions for the columns in this dataset.
+   * The comparators are then used to sort the dataset by the respective
+   * column. 
+   *
+   * @param {Column[]} dataCols Data columns (= non-image columns)
+   * @param {Column[]} imgCols Image columns.
+   *
+   * @return {Function[]} Array of functions that can be used to sort by the 
+   *                      respective column.
+   **/
+  DataRow.getCompareFunctions = function (dataCols, imgCols) {
+    var result = [];
+    for(var i=0, len=dataCols.length; i<len; i++) { 
+      result.push(( function (col, idx) { 
+        return function (a, b) {
+          return (a.dataCols[idx] < b.dataCols[idx]) ? -1 : 
+                 ((a.dataCols[idx] === b.dataCols[idx]) ? 0 : 1);
+        };
+      }(dataCols[i], i) ));
+    }
+
+    for(var i=0, len=imgCols.length; i<len; i++) { 
+      result.push((function (col, idx) { 
+        return function (a,b) {
+          var aVal = a.imageCols[idx].percent;
+          var bVal = b.imageCols[idx].percent;
+
+          return (aVal < bVal) ? -1 : ((aVal === bVal) ? 0 : 1);
+        };
+      }(imgCols[i], i) ));
+    }
+
+    return result;
+  };
+
+  /**
+  * Set the rowspan values of a given array of DataRow instances.
+  * 
+  * @param {DataRow[]} data Dataset in desired order (after sorting).
+  * @param {mergeRows} mergeRows Indicate whether to sort 
+   **/
+  DataRow.setRowspanValues = function (data, mergeRows) {
+    var curIdx, rowspan, cur;
+    if (mergeRows) { 
+      for(var i=0, len=data.length; i<len;) {
+        curIdx = i;
+        cur = data[i];
+        rowspan = 1;
+        for(i++; ((i<len) && (data[i].dataCols === cur.dataCols)); i++) {
+          rowspan++;
+          data[i].rowspan=0;
+        }
+        data[curIdx].rowspan = rowspan;
+      }
+    } else {
+      for(var i=0, len=data.length; i<len; i++) { 
+        data[i].rowspan = 1;
+      }
+    }
+  };
+
+  /**
+   * Wrapper class for image related data.
+   * 
+   * @param {string} url Relative Url of the image or null if not available.
+   * @param {float} percent Percent of pixels that are differing.
+   * @param {int} value Absolute number of pixes differing.
+   *
+   * @return {ImgVal} Instance of ImgVal.
+   **/
+  function ImgVal(url, percent, value) {
+    this.url = url;
+    this.percent = percent;
+    this.value = value;
+  }
+
+  /**
+   * Extracts the filter columns from the JSON response of the server. 
+   * 
+   * @param {object} data Server response. 
+   *
+   * @return {Column[]} List of filter columns as described in 'header' field. 
+   **/
+  function getFilterColumns(data) {
+    var result = [];
+    var vals = [];
+    var colOrder = data.extraColumnOrder;
+    var colHeaders = data.extraColumnHeaders;
+    var fopts, optVals, val;
+
+    for(var i=0, len=colOrder.length; i<len; i++) {
+      if (colHeaders[colOrder[i]].isFilterable) {
+        if (colHeaders[colOrder[i]].useFreeformFilter) {
+          result.push(Column.filter(colOrder[i], 
+                                    colHeaders[colOrder[i]].headerText, 
+                                    c.FILTER_FREE_FORM));
+          vals.push('');
+        }
+        else {
+          fopts = [];
+          optVals = [];
+
+          // extract the different options for this column
+          for(var j=0, jlen=colHeaders[colOrder[i]].valuesAndCounts.length; 
+              j<jlen; j++) {
+                val = colHeaders[colOrder[i]].valuesAndCounts[j];
+                fopts.push(new FilterOpt(val[0], val[1]));
+                optVals.push(false);
+          }
+
+          // ad the column and values
+          result.push(Column.filter(colOrder[i], 
+                                    colHeaders[colOrder[i]].headerText, 
+                                    c.FILTER_CHECK_BOX, 
+                                    fopts));
+          vals.push(optVals);
+        }
+      }
+    }
+
+    return [result, vals];
+  }
+
+  /**
+   * Extracts the image columns from the JSON response of the server. 
+   * 
+   * @param {object} data Server response. 
+   *
+   * @return {Column[]} List of images columns as described in 'header' field. 
+   **/
+  function getImageColumns(data) {
+    var CO = c.IMG_COL_ORDER;
+    var imgSet;
+    var result = [];
+    for(var i=0, len=CO.length; i<len; i++) { 
+      imgSet = data.imageSets[CO[i].key];
+      result.push(Column.image(CO[i].key, 
+                               imgSet.description, 
+                               ensureTrailingSlash(imgSet.baseUrl)));
+    }
+    return result;
+  }
+
+  /**
+   * Make sure Url has a trailing '/'. 
+   * 
+   * @param {string} url Base url. 
+   * @return {string} Same url with a trailing '/' or same as input if it 
+                      already contained '/'.
+   **/
+  function ensureTrailingSlash(url) { 
+    var result = url.trim();
+
+    // TODO: remove !!!
+    result = fixUrl(url);
+    if (result[result.length-1] !== '/') {
+      result += '/';
+    }
+    return result;
+  }
+
+  // TODO: remove. The backend should provide absoute URLs
+  function fixUrl(url) {
+    url = url.trim();
+    if ('http' === url.substr(0, 4)) {
+      return url;
+    }
+
+    var idx = url.indexOf('static');
+    if (idx != -1) {
+      return '/' + url.substr(idx);
+    }
+
+    return url;
+  };
+
+  /**
+   * Processes that data and returns filter functions. 
+   * 
+   * @param {object} Server response.
+   * @param {Column[]} filterCols Filter columns. 
+   * @param {Column[]} otherCols Columns that are neither filters nor images.
+   * @param {Column[]} imageCols Image columns.
+   *
+   * @return {[]} Returns a pair [dataRows, filterFunctions] where:
+   *       - dataRows is an array of DataRow instances.
+   *       - filterFunctions is an array of functions that can be used to 
+   *         filter the column at the corresponding index. 
+   *
+   **/
+  function getDataAndFilters(data, filterCols, otherCols, imageCols) {
+    var el;
+    var result = [];
+    var lookupIndices = [];
+    var indexerFuncs = [];
+    var temp;
+
+    // initialize the lookupIndices
+    var filterFuncs = initIndices(filterCols, lookupIndices, indexerFuncs);
+
+    // iterate over the data and get the rows
+    for(var i=0, len=data.imagePairs.length; i<len; i++) {
+      el = data.imagePairs[i];
+      temp = new DataRow(1, getColValues(el, filterCols, otherCols),
+                                 getImageValues(el, imageCols));
+      result.push(temp);
+
+      // index the row
+      for(var j=0, jlen=filterCols.length; j < jlen; j++) {
+        indexerFuncs[j](lookupIndices[j], filterCols[j], temp.dataCols[j], i);
+      }
+    }
+
+    setFreeFormFilterOptions(filterCols, lookupIndices);
+    return [result, filterFuncs];
+  }
+
+  /**
+   * Initiazile the lookup indices and indexer functions for the filter
+   * columns. 
+   * 
+   * @param {Column} filterCols Filter columns
+   * @param {[]} lookupIndices Will be filled with datastructures for 
+                               fast lookup (output parameter)
+   * @param {[]} lookupIndices Will be filled with functions to index data 
+                               of the column with the corresponding column.
+   *
+   * @return {[]} Returns an array of filter functions that can be used to 
+                  filter the respective column.  
+   **/
+  function initIndices(filterCols, lookupIndices, indexerFuncs) {
+    var filterFuncs = [];
+    var temp;
+
+    for(var i=0, len=filterCols.length; i<len; i++) { 
+      if (filterCols[i].ftype === c.FILTER_FREE_FORM) {
+        lookupIndices.push({});
+        indexerFuncs.push(indexFreeFormValue);
+        filterFuncs.push(
+          getFreeFormFilterFunc(lookupIndices[lookupIndices.length-1]));
+      }
+      else if (filterCols[i].ftype === c.FILTER_CHECK_BOX) { 
+        temp = [];
+        for(var j=0, jlen=filterCols[i].foptions.length; j<jlen; j++) {
+          temp.push([]);
+        }
+        lookupIndices.push(temp);
+        indexerFuncs.push(indexDiscreteValue);
+        filterFuncs.push(
+          getDiscreteFilterFunc(lookupIndices[lookupIndices.length-1]));
+      }
+    }
+
+    return filterFuncs; 
+  }
+
+  /**
+   * Helper function that extracts the values of free form columns from 
+   * the lookupIndex and injects them into the Column object as FilterOpt 
+   * objects.
+   **/
+  function setFreeFormFilterOptions(filterCols, lookupIndices) {
+    var temp, k;
+    for(var i=0, len=filterCols.length; i<len; i++) { 
+      if (filterCols[i].ftype === c.FILTER_FREE_FORM) { 
+        temp = []
+        for(k in lookupIndices[i]) { 
+          if (lookupIndices[i].hasOwnProperty(k)) { 
+            temp.push(new FilterOpt(k, lookupIndices[i][k].length));
+          }
+        }
+        filterCols[i].setFilterOptions(temp);
+      }
+    }
+  }
+
+  /**
+   * Index a discrete column (column with fixed number of values). 
+   *
+   **/
+  function indexDiscreteValue(lookupIndex, col, dataVal, dataRowIndex) {
+    var i = col.indexOfOptVal(dataVal);
+    lookupIndex[i].push(dataRowIndex);
+  }
+
+  /**
+   * Index a column with free form text (= not fixed upfront)
+   *
+   **/
+  function indexFreeFormValue(lookupIndex, col, dataVal, dataRowIndex) { 
+    if (!lookupIndex[dataVal]) { 
+      lookupIndex[dataVal] = [];
+    }
+    lookupIndex[dataVal].push(dataRowIndex);
+  }
+
+
+  /**
+   * Get the function to filter a column with the given lookup index
+   * for discrete (fixed upfront) values. 
+   * 
+   **/
+  function getDiscreteFilterFunc(lookupIndex) { 
+    return function(filterVal) {
+      var result = [];
+      for(var i=0, len=lookupIndex.length; i < len; i++) {
+        if (filterVal[i]) { 
+          // append the indices to the current array
+          result.push.apply(result, lookupIndex[i]);
+        }
+      }
+      return { nofilter: false, records: result };
+    };
+  }
+
+  /**
+   * Get the function to filter a column with the given lookup index
+   * for free form values.
+   * 
+   **/
+  function getFreeFormFilterFunc(lookupIndex) {
+    return function(filterVal) {
+      filterVal = filterVal.trim();
+      if (filterVal === '') {
+        return { nofilter: true };
+      }
+      return { 
+        nofilter: false, 
+        records: lookupIndex[filterVal] || []
+      };
+    };
+  }
+
+  /**
+   * Filters the data based on the given filterColumns and 
+   * corresponding filter values. 
+   * 
+   * @return {[]} Subset of the input dataset based on the 
+   *              filter values.
+   **/
+  function filterData(data, filterFuncs, filterVals) {
+    var recordSets = [];
+    var filterResult;
+
+    // run through all the filters
+    for(var i=0, len=filterFuncs.length; i<len; i++) { 
+      filterResult = filterFuncs[i](filterVals[i]);
+      if (!filterResult.nofilter) { 
+        recordSets.push(filterResult.records);
+      }
+    }
+
+    // If there are no restrictions then return the whole dataset.
+    if (recordSets.length === 0) {
+      return data;
+    } 
+
+    // intersect the records returned by filters. 
+    var targets = intersectArrs(recordSets);
+    var result = [];
+    for(var i=0, len=targets.length; i<len; i++) {
+      result.push(data[targets[i]]);
+    }
+
+    return result; 
+  }
+
+  /**
+   * Creates an object where the keys are the elements of the input array
+   * and the values are true. To be used for set operations with integer.
+   **/
+  function arrToObj(arr) { 
+    var o = {};
+    var i,len;
+    for(i=0, len=arr.length; i<len; i++) { 
+      o[arr[i]] = true;
+    }
+    return o;
+  }
+
+  /**
+   * Converts the keys of an object to an array after converting 
+   * each key to integer. To be used for set operations with integers.  
+   **/
+  function objToArr(obj) { 
+    var result = [];
+    for(var k in obj) {
+      if (obj.hasOwnProperty(k)) { 
+        result.push(parseInt(k));
+      }
+    }
+    return result;
+  }
+
+  /**
+   * Find the intersection of a set of arrays.
+   **/
+  function intersectArrs(sets) {
+    var temp, obj;
+
+    if (sets.length === 1) { 
+      return sets[0];
+    }
+
+    // sort by size and load the smallest into the object
+    sets.sort(function(a,b) { return a.length - b.length; });
+    obj = arrToObj(sets[0]); 
+
+    // shrink the hash as we fail to find elements in the other sets
+    for(var i=1, len=sets.length; i<len; i++) { 
+      temp = arrToObj(sets[i]);
+      for(var k in obj) {
+        if (obj.hasOwnProperty(k) && !temp[k]) { 
+          delete obj[k];
+        }
+      }
+    }
+    
+    return objToArr(obj);
+  }
+
+  /**
+   * Extract the column values from an ImagePair (contained in the server 
+   * response) into filter and data columns. 
+   *
+   * @return {[]} Array of data contained in one data row.
+   **/
+  function getColValues(imagePair, filterCols, otherCols) { 
+    var result = [];
+    for(var i=0, len=filterCols.length; i<len; i++) { 
+      result.push(imagePair.extraColumns[filterCols[i].key]);
+    }
+
+    for(var i=0, len=otherCols.length; i<len; i++) { 
+      result.push(get_robust(imagePair, ['expectations', otherCols[i].key]));
+    }
+
+    return result;
+  }
+
+  /**
+   * Extract the image meta data from an Image pair returned by the server.
+   **/
+  function getImageValues(imagePair, imageCols) {
+    var result=[];
+    var url, value, percent, diff;
+    var CO = c.IMG_COL_ORDER;
+
+    for(var i=0, len=imageCols.length; i<len; i++) {
+      percent = get_robust(imagePair, CO[i].percentField);
+      value = get_robust(imagePair, CO[i].valueField);
+      url = get_robust(imagePair, CO[i].urlField);
+      if (url) { 
+        url = imageCols[i].baseUrl + url;
+      }
+      result.push(new ImgVal(url, percent, value));
+    }
+
+    return result;
+  }
+
+  /**
+   * Given an object find sub objects for the given index without 
+   * throwing an error if any of the sub objects do not exist. 
+   **/
+  function get_robust(obj, idx) {
+    if (!idx) {
+      return;
+    }
+
+    for(var i=0, len=idx.length; i<len; i++) {
+      if ((typeof obj === 'undefined') || (!idx[i])) {
+        return;  // returns 'undefined'
+      }
+
+      obj = obj[idx[i]];
+    }
+
+    return obj;
+  }
+
+  /**
+   * Set all elements in the array to the given value. 
+   **/
+  function setArrVals(arr, newVal) { 
+    for(var i=0, len=arr.length; i<len; i++) { 
+      arr[i] = newVal;
+    }
+  }
+
+  /**
+   * Toggle the elements of a boolean array. 
+   * 
+   **/
+  function toggleArrVals(arr) { 
+    for(var i=0, len=arr.length; i<len; i++) { 
+      arr[i] = !arr[i];
+    }
+  }
+
+  /**
+   * Sort the array of DataRow instances with the given compare functions 
+   * and the column at the given index either in ascending or descending order.
+   **/
+  function sortData (allData, compareFunctions, sortByIdx, sortOrderAsc) {
+    var cmpFn = compareFunctions[sortByIdx];
+    var useCmp = cmpFn;
+    if (!sortOrderAsc) {
+      useCmp = function ( _ ) {
+        return -cmpFn.apply(this, arguments);
+      };
+    }
+    allData.sort(useCmp);
+  }
+
+
+  // *****************************  Services *********************************
+
+  /**  
+   *  Encapsulates all interactions with the backend by handling 
+   *  Urls and HTTP requests. Also exposes some utility functions
+   *  related to processing Urls. 
+   */
+  app.factory('dataService', [ '$http', function ($http) {
+    /** Backend related constants  **/ 
+    var c = {
+      /** Url to retrieve failures */ 
+      FAILURES: '/results/failures',
+
+      /** Url to retrieve all GM results */ 
+      ALL:      '/results/all'
+    };
+
+    /**
+     * Convenience function to retrieve all results.
+     * 
+     * @return {Promise} Will resolve to either the data (success) or to 
+     *                   the HTTP response (error).
+     **/
+    function loadAll() {
+      return httpGetData(c.ALL);
+    }
+
+    /**
+     * Make a HTTP get request with the given query parameters.
+     * 
+     * @param {} 
+     * @param {}
+     *
+     * @return {} 
+     **/
+    function httpGetData(url, queryParams) {
+      var reqConfig = {
+        method: 'GET',
+        url: url,
+        params: queryParams
+      };
+
+      return $http(reqConfig).then(
+        function(successResp) {
+          return successResp.data;
+        });
+    }
+
+    /**
+     * Takes an arbitrary number of objects and generates a Url encoded
+     * query string.
+     *
+     **/
+    function getQueryString( _params_ ) {
+      var result = [];
+      for(var i=0, len=arguments.length; i < len; i++) {
+        if (arguments[i]) {
+          for(var k in arguments[i]) { 
+            if (arguments[i].hasOwnProperty(k)) {
+              result.push(encodeURIComponent(k) + '=' + 
+                          encodeURIComponent(arguments[i][k]));
+            }
+          }
+        }
+      }
+      return result.join("&");
+    }
+
+    // Interface of the service:
+    return {
+      getQueryString: getQueryString,
+      loadAll: loadAll
+    };
+
+  }]);  
+
+})();