FEAT: Add the ability to delay the execution of client-side evidence properties.

This is used to control the execution of JavaScript that would cause UI elements to be show to the user. For example, the 'allow website to access your location' popup.

Changes to json bundler, javascript builder (minor new setting change) and tests.

Related work items: #3826

Author: FilipNest

JavaScriptResource.mustache

@@ -20,6 +20,9 @@ fiftyoneDegreesManager = function() {
     // by 1.
     var callbackCounter = 0;
 
+    // Array of JavaScript properties that have started evaluation.
+    var jsPropertiesStarted = [];
+
     // startsWith polyfill.
     var startsWith = function(source, searchValue){
         return source.lastIndexOf(searchValue, 0) === 0;
@@ -63,8 +66,11 @@ fiftyoneDegreesManager = function() {
     // Fetch a value safely from the json object. If a key somewhere down the
     // '.' separated hierarchy of keys is not present then 'undefined' is
     // returned rather than letting an exception occur.
-    var getFromJson = function(key) {
+    var getFromJson = function(key, allowObjects, allowBooleans) {
         var result = undefined;
+        if(typeof allowObjects === 'undefined') { allowObjects = false; }
+        if(typeof allowBooleans === 'undefined') { allowBooleans = false; }
+
         if (typeof(key) === 'string') {
             var functions = json;
             var segments = key.split('.');
@@ -74,6 +80,10 @@ fiftyoneDegreesManager = function() {
             }
             if (typeof(functions) === "string") {
                 result = functions;
+            } else if (allowBooleans && typeof(functions) === "boolean") {
+                result = functions;
+            } else if (allowObjects && typeof functions === 'object' && functions !== null) {
+                result = functions;
             }
         }
         return result;
@@ -95,56 +105,66 @@ fiftyoneDegreesManager = function() {
 
     // Executes any Javascript contained in the json data. Sets the processedJs
     // flag to true when there is no further Javascript to be processed.
-    var processJSproperties = function(resolve, reject) {
+    var processJsProperties = function(resolve, reject, jsProperties, ignoreDelayFlag) {
         var executeCallback = true;
+        var started = 0;
 
-        if (json.javascriptProperties !== undefined &&
-            json.javascriptProperties.length > 0) {
+        if (jsProperties !== undefined &&
+            jsProperties.length > 0) {
 
             // Execute each of the Javascript property code snippets using the
             // index of the value to access the value to avoid problems with
             // JavaScript returning erroneous values.
             for(var index = 0;
-                index < json.javascriptProperties.length;
+                index < jsProperties.length;
                 index++) {
 
-                var name = json.javascriptProperties[index];
-
-                // Create new function bound to this instance and execute it.
-                // This is needed to ensure the scope of the function is
-                // associated with this instance if any members are altered or
-                // added. Avoids global scoped variables.
-                var body = getFromJson(name);
-
-                if (body !== undefined) {
-                    var func = undefined;
-                    var searchString = '// 51D replace this comment with callback function.';
-
-                    if(body.indexOf(searchString) !== -1){
-                        callbackCounter++;
-                        body = body.replace(/\/\/ 51D replace this comment with callback function./g, 'callbackFunc(resolveFunc, rejectFunc);');
-                        func = new Function('callbackFunc', 'resolveFunc', 'rejectFunc',
-                            "try {\n" +
-                            body + "\n" +
-                            "} catch (err) {\n" +
-                            "console.log(err);" +
-                            "}"
-                        );
-                        func(completedCallback, resolve, reject);
-                        executeCallback = false;
-                    } else {
-                        func = new Function(
-                            "try {\n" +
-                            body + "\n" +
-                            "} catch (err) {\n" +
-                            "console.log(err);" +
-                            "}"
-                        );
-                        func();
+                var name = jsProperties[index];
+
+                if(jsPropertiesStarted.includes(name) === false) {
+                    // Create new function bound to this instance and execute it.
+                    // This is needed to ensure the scope of the function is
+                    // associated with this instance if any members are altered or
+                    // added. Avoids global scoped variables.
+                    var body = getFromJson(name);
+                    var delay = getFromJson(name + 'delayexecution', false, true);
+
+                    if ((ignoreDelayFlag || (delay === undefined || delay === false)) &&
+                        body !== undefined) {
+                        var func = undefined;
+                        var searchString = '// 51D replace this comment with callback function.';
+                        completed = false;
+                        jsPropertiesStarted.push(name);
+                        started++;
+
+                        if(body.indexOf(searchString) !== -1){
+                            callbackCounter++;
+                            body = body.replace(/\/\/ 51D replace this comment with callback function./g, 'callbackFunc(resolveFunc, rejectFunc);');
+                            func = new Function('callbackFunc', 'resolveFunc', 'rejectFunc',
+                                "try {\n" +
+                                body + "\n" +
+                                "} catch (err) {\n" +
+                                "console.log(err);" +
+                                "}"
+                            );
+                            func(completedCallback, resolve, reject);
+                            executeCallback = false;
+                        } else {
+                            func = new Function(
+                                "try {\n" +
+                                body + "\n" +
+                                "} catch (err) {\n" +
+                                "console.log(err);" +
+                                "}"
+                            );
+                            func();
+                        }
                     }
                 }
             }
-        } else {
+        }
+
+        if(started === 0) {
             executeCallback = false;
             completed = true;
         }
@@ -198,7 +218,7 @@ fiftyoneDegreesManager = function() {
 
     // Process the JavaScript properties.
     var process = function(resolve, reject){
-        processJSproperties(resolve, reject);
+        processJsProperties(resolve, reject, json.javascriptProperties, false);
     }
 
     var fireChangeFuncs = function(json) {
@@ -308,6 +328,59 @@ fiftyoneDegreesManager = function() {
         });
     }
 
+{{#_hasDelayedProperties}}
+    // Get the JS property(s) that, when evaluated, will populate
+    // evidence that can be used to determine the value of the
+    // supplied property.
+    // The supplied name can either be a complete property name or a top level
+    // aspect name.
+    // Where the aspect name is given, ALL evidence properties under that
+    // key will be returned.
+    // Example property names are 'location.country' or 'devices.profiles.hardwarename'
+    // Example aspect names are 'location' or 'devices'
+    var getEvidenceProperties = function (name) {
+        var evidenceProperties = getFromJson(name + 'evidenceproperties');
+        if(typeof evidenceProperties === "undefined") {
+            var item = getFromJson(name, true);
+            evidenceProperties = getEvidencePropertiesFromObject(item);
+        }
+        return evidenceProperties;
+    }
+
+    // Get all values in any 'evidenceproperty' fields on this object
+    // or sub-objects.
+    var getEvidencePropertiesFromObject = function (dataObject) {
+        evidenceProperties = [];
+
+        for (var prop in dataObject) {
+            if (dataObject.hasOwnProperty(prop)) {
+                var value = dataObject[prop];
+                // Property name ends with 'evidenceproperties' so is
+                // what we're looking for.
+                // Add the values to the array if we don't already have it.
+                if (value !== null && Array.isArray(value) && prop.endsWith('evidenceproperties')) {
+                    value.forEach(function(item, index) {
+                        if(evidenceProperties.includes(item) === false) {
+                            evidenceProperties.push(item);
+                        }
+                    });
+                }
+                // Item is an object so recursively call this method
+                // and add any resulting evidence properties to the list.
+                else if(typeof value === 'object' && value !== null) {
+                    getEvidencePropertiesFromObject(value).forEach(function(item, index) {
+                        if(evidenceProperties.includes(item) === false) {
+                            evidenceProperties.push(item);
+                        }
+                    });
+                }
+            }
+        }
+
+        return evidenceProperties;
+    }
+{{/_hasDelayedProperties}}
+
 {{#_supportsPromises}}
     this.promise = new Promise(function(resolve, reject) {
         process(resolve,reject);
@@ -318,7 +391,28 @@ fiftyoneDegreesManager = function() {
 		changeFuncs.push(resolve);
 	}
 
-    this.complete = function(resolve) {
+    this.complete = function(resolve, properties) {
+{{#_hasDelayedProperties}}
+        // If properties is set then check if we need to kick off
+        // processing of anything.
+        if(typeof properties !== "undefined") {
+            // If properties is a string then split on comma to produce
+            // an array of one or more key names.
+            if(typeof properties === "string") {
+                properties = properties.split(',');
+            }
+            if(Array.isArray(properties)) {
+                properties.forEach(function(key, i) {
+                    // We pass an empty function rather than 'resolve' because we
+                    // don't want to call resolve when a single evidence function
+                    // evaluates but after all of them have completed.
+                    // This is handled by the 'if(complete)' code below.
+                    processJsProperties(function(json) {}, catchError, getEvidenceProperties(key), true);
+                });
+            }
+        }
+
+{{/_hasDelayedProperties}}
         if(completed){
             resolve(json);
         }else{
@@ -337,7 +431,6 @@ fiftyoneDegreesManager = function() {
     this.promise.then(function(value) {
         // JSON has been updated so replace the current instance.
         update.call(parent, value);
-        resolve(parent);
         completed = true;
     }).catch(catchError);
 {{/_supportsPromises}}

JavascriptBuilder.php

@@ -162,7 +162,11 @@ public function processInternal($flowData)
         } else {
             $vars["_supportsPromises"] = false;
         }
-          
+
+        // Check if any delayedproperties exist in the json
+
+        $vars["_hasDelayedProperties"] = strpos($vars["_jsonObject"], "delayexecution") !== false;
+         
         $output = $m->render(file_get_contents(__DIR__ . "/JavaScriptResource.mustache"), $vars);
 
         if($this->minify) {