I'm doing an experiment with wxWebConnect test application, incorporating the xpcom tutorial at "http://nerdlife.net/building-a-c-xpcom-component-in-windows/"
I adapt MyComponent class as necessary to compile together with testapp.exe (not as separate dll), and on MyApp::OnInit I have the following lines:
ns_smartptr<nsIComponentRegistrar> comp_reg;
res = NS_GetComponentRegistrar(&comp_reg.p);
if (NS_FAILED(res))
return false;
ns_smartptr<nsIFactory> prompt_factory;
CreateMyComponentFactory(&prompt_factory.p);
nsCID prompt_cid = MYCOMPONENT_CID;
res = comp_reg->RegisterFactory(prompt_cid,
"MyComponent",
"#mozilla.org/mycomp;1",
prompt_factory);
Those lines are copied from GeckoEngine::Init(), using the same mechanism to register PromptService, etc. The code compiles well and testapp.exe is running as expected.
I put javascript test as below :
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
const cid = "#mozilla.org/mycomp;1";
obj = Components.classes[cid].createInstance();
alert(typeof obj);
// bind the instance we just created to our interface
alert(Components.interfaces.nsIMyComponent);
obj = obj.QueryInterface(Components.interfaces.nsIMyComponent);
} catch (err) {
alert(err);
return;
}
and get the following exception:
Could not convert JavaScript argument arg 0 [nsISupport.QueryInterface]
The first alert says "object", so the line
Components.classes[cid].createInstance()
is returning the created instance.
The second alert says "undefined", so the interface nsIMyComponent is not recognized by XULRunner.
How to dynamically registering nsIMyComponent interface in wxWebConnect environment ?
Thx
I'm not sure what is happening here. The first thing I would check is that your component is scriptable (I assume it is, since the demo you copy from is). The next thing I would check is whether you can instantiate other, standard XULRunner components and get their interface (try something like "alert('Components.interfaces.nsIFile');" - at least in my version of wxWebConnect this shows an alert box with string "nsIFile".
Also, I think it would be worth checking the Error Console to make sure there are no errors or warnings reported. A magic string to do that (in Javascript) is:
window.open('chrome://global/content/console.xul', '', 'chrome,dialog=no,toolbar,resizable');
Related
I'm trying to find a way to make my Stimulus controller more robust and maintainable by checking that all the required targets are present. If something is missing, I would like it to fail fast and loud.
Below is what I'm using so far:
export default class extends Controller {
static targets = ['name'];
connect() {
if (!that.hasNameTarget) {
throw new Error('expected to find name target');
}
}
}
Perhaps someone knows of a more idiomatic/clean solution?
Option 1 - use the Stimulus debugger tooling
Stimulus has a debug mode that logs out info/warnings etc for Stimulus controllers. You can enable this by stimulus.debug = true;
You can call this in your own controllers via this.application.logDebugActivity() - see https://github.com/hotwired/stimulus/blob/main/src/core/application.ts#L95
export default class extends Controller {
static targets = ['name'];
connect() {
if (!that.hasNameTarget) {
this.logDebugActivity(this.identifier, 'error', { message: 'target missing'});
throw new Error('expected to find name target');
}
}
}
Option 2 - Use the window.onerror callback
If you keep your current code where an error is thrown, Stimulus will not 'break' anything where possible as all calls within Stimulus use try/catch.
However, you can ensure that your error does something 'loud' by creating a onerror function.
See docs - https://stimulus.hotwired.dev/handbook/installing#error-handling
See an example where this can be used for something like Sentry https://blog.sentry.io/2016/01/04/client-javascript-reporting-window-onerror
You could also just be really loud and block the UI with something similar to this.
window.onerror = (message, url, lineNo, columnNo, error) => {
document.body.style.backgroundColor = 'red';
window.alert(message);
}
Reminders
Remember to only enable these debugging features in local development, you can do this with something like Webpack environment variables but this will be different depending on your tooling.
In production though you may want to push your onerror calls to whatever logging infrastructure you have.
stimulus.debug mode is quite 'noisy' and may be too much information, depending on your set up.
I have a Spock class, that when run as a test suite, throws Unable to resolve iconRow as content for geb.Page, or as a property on its Navigator context. Is iconRow a class you forgot to import? unless I annotate my class with #Stepwise. However, I really don't want the test execution to stop on the first failure, which #Stepwise does.
I've tried writing (copy and pasting) my own extension using this post, but I still get these errors. It is using my extension, as I added some logging statements that were printed out to the console.
Here is one of my modules:
class IconRow extends Module {
static content = {
iconRow (required: false) {$("div.report-toolbar")}
}
}
And a page that uses it:
class Report extends SomeOtherPage {
static at = {$("div.grid-container").displayed}
static content = {
iconRow { module IconRow }
}
}
And a snippet of the test that is failing:
class MyFailingTest extends GebReportingSpec {
def setupSpec() {
via Dashboard
SomeClass.login("SourMonk", "myPassword")
assert page instanceof Dashboard
nav.goToReport("Some report name")
assert page instanceof Report
}
#Unroll
def "I work"() {
given:
at Report
expect:
this == that
where:
this << ["some list", "of values"]
that << anotherModule.someContent*.#id
}
#Unroll
def "I don't work"() {
given:
at Report
expect:
this == that
where:
this << ["some other", "list", "of values"]
that << iconRow.columnHeaders*.attr("innerText")*.toUpperCase()
}
}
When executed as a suite I work passes and I don't work fails because it cannot identify "iconRow" as content for the page. If I switch the order of the test cases, I don't work will pass and I work will fail. Alternatively, if I execute each test separately, they both pass.
What I have tried:
Adding/removing the required: true property from content in the modules
Prefixing the module name with the class, such as IconRow.iconRow
Defining my modules as static #Shared properties
Initialize the modules both in and outside of my setupSpec()
Making simple getter methods in each module's class that return the module, and referencing content such as IconRow.getIconRow().columnHeaders*.attr("innerText")*.toUpperCase()
Moving the contents of my setupSpec() into setup()
Adding autoClearCookies = false into my GebConfig.groovy
Making a #Shared Report report variable and prefix all modules with that such as report.iconRow
Very peculiar note about that last bullet point -- it magically resolves the modules that don't have the prefix -- so it won't resolve report.IconRow but will resolve just iconRow -- absolutely bizarre, because if I remove that variable the module that was just previously working suddenly can't be resolved again. I even tried declaring this variable and then not prefixing anything, and that did not work either.
Another problem that I keep banging my head against the wall with is that I'm also not sure of where the problem is. The error it throws leads me to believe that it's a project setup issue, but running each feature individually works fine, so it appears to be resolving the classes just fine.
On the other hand, perhaps it's an issue with the session and/or cookies? Although I have yet to see any official documentation on this, it seems to be the general consensus (from other posts and articles I've read) that only using #Stepwise will maintain your session between feature methods. If this is the case, why is my extension not working? It's pretty much a copy and paste of #Stepwise without the skipFeaturesAfterFirstFailingFeature method (I can post if needed), unless there is some other stuff going on behind the scenes with #Stepwise.
Apologies for the wall of text, but I've been trying to figure this out for about 6 hours now, so my brain is pretty fried.
Geb has special support for #Stepwise, if a spec is annotated with it it does not call resetBrowser() after each test, instead it is called after the spec is completed. See the code on github
So basically you need to change your setupSpec to setup so that it will be executed before each test.
Regarding your observation, if you just run a focused test the setupSpec is executed for that test and thus it passes. The problem arises, that the cleanup is invoked afterwards and resets the browser, breaking subsequent tests.
EDIT
I overlooked your usage of where blocks, everything in the where block needs to be statically (#Shared) available, so using instance level constructs won't work. Resetting the browser will also kill every reference so just getting it before wont work either. Basically, don't use Geb objects in where blocks!
Looking at your code however I don't see any reason to use data driven tests here.
This can be easily done with one assertion in a normal test
It is good practice for unit tests to just test one thing. Geb however, is not an unit test but an acceptance/frontend test. The problem here is that they are way slower than unit tests and it makes sense to combine sensible assertions into one test.
class MyFailingTest extends GebReportingSpec {
def setup() {
via Dashboard
SomeClass.login("SourMonk", "myPassword")
assert page instanceof Dashboard
nav.goToReport("Some report name")
assert page instanceof Report
}
def "I work"() {
given:
at Report
expect:
["some list", "of values"] == anotherModule.someContent*.#id
}
def "I don't work"() {
given:
at Report
expect:
["some other", "list", "of values"] == iconRow.columnHeaders*.attr("innerText")*.toUpperCase()
}
}
Since getting started in Dart I've been watching for a way to execute Dart (Text) Source (that the same program may well be generating dynamically) as Code. Like the infamous "eval()" function.
Recently I have caught a few hints that the communication port between Isolates support some sort of "Spawn" that seems like it could allow this "trick". In Ruby there is also the possibility to load a module dynamically as a language feature, perhaps there is some way to do this in Dart?
Any clues or a simple example will be greatly appreciated.
Thanks in advance!
Ladislav Thon provided this answer on the Dart forum:
I believe it's very safe to say that Dart will never have eval. But it will have other, more structured ways of dynamically generating code (code name mirror builders). There is nothing like that right now, though.
There are two ways of spawning an isolate: spawnFunction, which runs an existing function from the existing code in a new isolate, so nothing you are looking for, and spawnUri, which downloads code from given URI and runs it in new isolate. That is essentially dynamic code loading -- but the dynamically loaded code is isolated from the existing code. It runs in a new isolate, so the only means of communicating with it is via message passing (through ports).
You can run a string as Dart code by first constructing a data URI from it and then passing it into Isolate.spawnUri.
import 'dart:isolate';
void main() async {
final uri = Uri.dataFromString(
'''
void main() {
print("Hellooooooo from the other side!");
}
''',
mimeType: 'application/dart',
);
await Isolate.spawnUri(uri, [], null);
}
Note that you can only do this in JIT mode, which means that the only place you might benefit from it is Dart VM command line apps / package:build scripts. It will not work in Flutter release builds.
To get a result back from it, you can use ports:
import 'dart:isolate';
void main() async {
final name = 'Eval Knievel';
final uri = Uri.dataFromString(
'''
import "dart:isolate";
void main(_, SendPort port) {
port.send("Nice to meet you, $name!");
}
''',
mimeType: 'application/dart',
);
final port = ReceivePort();
await Isolate.spawnUri(uri, [], port.sendPort);
final String response = await port.first;
print(response);
}
I wrote about it on my blog.
Eval(), in Ruby at least, can execute anything from a single statement (like an assignment) to complete involved programs. There is a substantial time penalty for executing many small snippets over most any other form of execution that is possible.
Looking at the problem closer, there are at least three different functions that were at the base of the various schemes where eval might be used. Dart handles at least 2 of these in at least minimal ways.
Dart does not, nor does it look like there is any plan to support "general" script execution.
However, the NoSuchMethod method can be used to effectively implement the dynamic "injection" of variables into your local class environment. It replaces an eval() with a string that would look like this: eval( "String text = 'your first name here';" );
The second function that Dart readily supports now is the invocation of a method, that would look like this: eval( "Map map = SomeClass.some_method()" );
After messing about with this it finally dawned on me that a single simple class can be used to store the information needed to invoke a method, for a class, as a string which seems to have general utility. I can replace a big maintenance prone switch statement that might otherwise be necessary to invoke a series of methods. In Ruby this was almost trivial, however in Dart there are some fairly less than intuitive calls so I wanted to get this "trick" in one place, which fits will with doing ordering and filtering on the strings such as you may need.
Here's the code to "accumulate" as many classes (a whole library?) into a map using reflection such that the class.methodName() can be called with nothing more than a key (as a string).
Note: I used a few "helper methods" to do Map & List functions, you will probably want to replace them with straight Dart. However this code is used and tested only using the functions..
Here's the code:
//The used "Helpers" here..
MAP_add(var map, var key, var value){ if(key != null){map[key] = value;}return(map);}
Object MAP_fetch(var map, var key, [var dflt = null]) {var value = map[key];if (value==null) {value = dflt;}return( value );}
class ClassMethodMapper {
Map _helperMirrorsMap, _methodMap;
void accum_class_map(Object myClass){
InstanceMirror helperMirror = reflect(myClass);
List methodsAr = helperMirror.type.methods.values;
String classNm = myClass.toString().split("'")[1]; ///#FRAGILE
MAP_add(_helperMirrorsMap, classNm, helperMirror);
methodsAr.forEach(( method) {
String key = method.simpleName;
if (key.charCodeAt(0) != 95) { //Ignore private methods
MAP_add(_methodMap, "${classNm}.${key}()", method);
}
});
}
Map invoker( String methodNm ) {
var method = MAP_fetch(_methodMap, methodNm, null);
if (method != null) {
String classNm = methodNm.split('.')[0];
InstanceMirror helperMirror = MAP_fetch(_helperMirrorsMap, classNm);
helperMirror.invoke(method.simpleName, []);
}
}
ClassMethodMapper() {
_methodMap = {};
_helperMirrorsMap = {};
}
}//END_OF_CLASS( ClassMethodMapper );
============
main() {
ClassMethodMapper cMM = new ClassMethodMapper();
cMM.accum_class_map(MyFirstExampleClass);
cMM.accum_class_map(MySecondExampleClass);
//Now you're ready to execute any method (not private as per a special line of code above)
//by simply doing this:
cMM.invoker( MyFirstExampleClass.my_example_method() );
}
Actually there some libraries in pub.dev/packages but has some limitations because are young versions, so that I can recommend you this library expressions to dart and flutter.
A library to parse and evaluate simple expressions.
This library can handle simple expressions, but no blocks of code, control flow statements and so on. It supports a syntax that is common to most programming languages.
There I create an example of code to evaluate arithmetic operations and comparations of data.
import 'package:expressions/expressions.dart';
import 'dart:math';
#override
Widget build(BuildContext context) {
final parsing = FormulaMath();
// Expression example
String condition = "(cos(x)*cos(x)+sin(x)*sin(x)==1) && respuesta_texto == 'si'";
Expression expression = Expression.parse(condition);
var context = {
"x": pi / 5,
"cos": cos,
"sin": sin,
"respuesta_texto" : 'si'
};
// Evaluate expression
final evaluator = const ExpressionEvaluator();
var r = evaluator.eval(expression, context);
print(r);
return Scaffold(
body: Container(
margin: EdgeInsets.only(top: 50.0),
child: Column(
children: [
Text(condition),
Text(r.toString())
],
),
),
);
}
I/flutter (27188): true
The problem: I'm crashing when I want to render my incoming data which was retrieved asynchronously.
The app starts and displays some dialog boxes using XAML. Once the user fills in their data and clicks the login button, the XAML class has in instance of a worker class that does the HTTP stuff for me (asynchronously using IXMLHTTPRequest2). When the app has successfully logged in to the web server, my .then() block fires and I make a callback to my main xaml class to do some rendering of the assets.
I am always getting crashes in the delegate though (the main XAML class), which leads me to believe that I cannot use this approach (pure virtual class and callbacks) to update my UI. I think I am inadvertently trying to do something illegal from an incorrect thread which is a byproduct of the async calls.
Is there a better or different way that I should be notifying the main XAML class that it is time for it to update it's UI? I am coming from an iOS world where I could use NotificationCenter.
Now, I saw that Microsoft has it's own Delegate type of thing here: http://msdn.microsoft.com/en-us/library/windows/apps/hh755798.aspx
Do you think that if I used this approach instead of my own callbacks that it would no longer crash?
Let me know if you need more clarification or what not.
Here is the jist of the code:
public interface class ISmileServiceEvents
{
public: // required methods
virtual void UpdateUI(bool isValid) abstract;
};
// In main XAML.cpp which inherits from an ISmileServiceEvents
void buttonClick(...){
_myUser->LoginAndGetAssets(txtEmail->Text, txtPass->Password);
}
void UpdateUI(String^ data) // implements ISmileServiceEvents
{
// This is where I would render my assets if I could.
// Cannot legally do much here. Always crashes.
// Follow the rest of the code to get here.
}
// In MyUser.cpp
void LoginAndGetAssets(String^ email, String^ password){
Uri^ uri = ref new URI(MY_SERVER + "login.json");
String^ inJSON = "some json input data here"; // serialized email and password with other data
// make the HTTP request to login, then notify XAML that it has data to render.
_myService->HTTPPostAsync(uri, json).then([](String^ outputJson){
String^ assets = MyParser::Parse(outputJSON);
// The Login has returned and we have our json output data
if(_delegate)
{
_delegate->UpdateUI(assets);
}
});
}
// In MyService.cpp
task<String^> MyService::HTTPPostAsync(Uri^ uri, String^ json)
{
return _httpRequest.PostAsync(uri,
json->Data(),
_cancellationTokenSource.get_token()).then([this](task<std::wstring> response)
{
try
{
if(_httpRequest.GetStatusCode() != 200) SM_LOG_WARNING("Status code=", _httpRequest.GetStatusCode());
String^ j = ref new String(response.get().c_str());
return j;
}
catch (Exception^ ex) .......;
return ref new String(L"");
}, task_continuation_context::use_current());
}
Edit: BTW, the error I get when I go to update the UI is:
"An invalid parameter was passed to a function that considers invalid parameters fatal."
In this case I am just trying to execute in my callback is
txtBox->Text = data;
It appears you are updating the UI thread from the wrong context. You can use task_continuation_context::use_arbitrary() to allow you to update the UI. See the "Controlling the Execution Thread" example in this document (the discussion of marshaling is at the bottom).
So, it turns out that when you have a continuation, if you don't specify a context after the lambda function, that it defaults to use_arbitrary(). This is in contradiction to what I learned in an MS video.
However by adding use_currrent() to all of the .then blocks that have anything to do with the GUI, my error goes away and everything is able to render properly.
My GUI calls a service which generates some tasks and then calls to an HTTP class that does asynchronous stuff too. Way back in the HTTP classes I use use_arbitrary() so that it can run on secondary threads. This works fine. Just be sure to use use_current() on anything that has to do with the GUI.
Now that you have my answer, if you look at the original code you will see that it already contains use_current(). This is true, but I left out a wrapping function for simplicity of the example. That is where I needed to add use_current().
[I'm a YUI newbie]
I'm writing a Chrome extension that needs to change the contents of a web page created using the YUI3 framework.
I've identified that the extension, which injects javascript that runs in the page after it is loaded, must call a function that was previously defined in a YUI.add() call.
The original YUI code that runs is something like this:
YUI.add("uuu", function (c) {
...
c.theObject = niceStuff;
}
...
YUI().use("uuu", function (c) {
c.theObject.doSomething();
}
Is it possible that after this code runs, I can access a function of c.theObject?
(I understand this might go against YUI3's nice sandbox mechanism, but it's what I need to get the job done here).
You might have problems because any time a YUI() instance is created, it builds you a new sandbox. With a few exceptions, YUI modules are completely boxed by their sandbox context. For example:
YUI().use('node', function(Y1) {
YUI().use('node', function(Y2) {
assert(Y1.Node === Y2.Node) // fails!
});
});
It's very possible that you may not be able to access the specific instance of theObject that you need, if it's never assigned to a variable outside the sandbox function scope. If any instance of theObject will do, you can just call into the YUI API and get your own version to play with.
This works for me: http://jsfiddle.net/sMAQx/1/
One way to do it is to capture the YUI() instance after you 'use' it. Like this:
YUI().add("uuu", function (c) {
c.theObject = 'foo';
})
var yInstance = YUI().use("uuu", function (c) {
c.theObject = 'booyaa';
})
yInstance.use('uuu',function(c){
console.log(c.theObject)
})
// booyaa