I created a dynamic object and try to register it with RegisterJsObject. However, the javascript code on the client side doesn't recongize the register js object and I can't call any of the functions that are par tof the dynamic object.
Ex.
C# code:
dynamic obj = new ExpandoObject();
obj.FullName = new Action(() =>
{
Console.WriteLine("FullName method called");
});
Cef.Initialize(new CefSettings());
ChromiumWebBrowser browser = new ChromiumWebBrowser("");
browser.RegisterJsObject("pesonObj", obj);
Javascript Code
personObj.fullName();
Even when I examine the javascript object personObj in a developer's console, it doesn't have the fullName function.
If I create a normal class that isn't dynamic, this isn't the case and works as expected.
So the question is, does Chromium support dynamicObject for registering as javascript objects in the embedded browser.
Any advice appreciated,
Thanks,
D
Related
I implemented Shepherd in my Vaadin Project, so i can guide users in tours through my web application.
But, i need to get access from the javascript on the Accordion Components in Vaadin, to open or close specific tabs. For this, i need to have access on the open() and close() method for the Accordion Components. So how can i access them through Javascript?
Already seen the Tutorial on the Website of them:
Vaadin calling java from javascript,
but sadly nothing over there, what could help me.
I already tried to use something like this:
UI.getCurrent().getPage().executeJs("window.startTour($0, $1)", this, Accordion1.getElement());
But when i try to bind it in javascript through:
window.startTour = (element, accordion) => { ... }
and in this window:
beforeShowPromise: function () {
return new Promise(function(resolve) {
element.$server.openAccordion(accordion.$server, 1);
resolve();
});
},
with the following method in java:
#SuppressWarnings("unused")
#ClientCallable
public void openAccordion(Object object, int index) {
Accordion accordion = (Accordion) object.get(this);
accordion.open(index);
}
i only get the following error message:
Class '...' has the method 'openAccordion' whose parameter 0 refers to unsupported type 'java.lang.Object'
No matter what i use as first parameter, everythin that extends Object doesnt work and i dont know why.
I found a recent post with the same question, but it was not helpful for me:
Unable to send a new bean instance to the server
Im using Intellij and in my Project: Java, Spring, Vaadin and Shepherd
Already tried to use different parameters, but only the int parameter is working, Object doesnt work.
The Problem is, i cant change the opened Tab of the Accordion from the Javascript over the Java, because of this error, so i have to implement for each Accordion 2 methods to open and close it.
Maybe somebody can help me with it or knows some tricks to master this.
Thanks
When using #ClientCallable you can pass only json or primitive types from JavaScript call to server. There is a real systems boundary here. Object is not supported and furthermore, you can cast that parameter to Java object.
I have created the following class (condensed version), heres a reference to the full file
https://github.com/cotyembry/CastRemoteNative/blob/7e74dbc56f037cc61241f6ece24a94d8c52abb32/root/ios/CastRemoteNative/NativeMethods.swift
#objc(NativeMethods)
class NativeMethods: RCTEventEmitter {
#objc(sendEventToJSFromJS)
func sendEventToJSFromJS {
self.emitEvent(eventName: "test", body: "bodyTestString")
}
func emitEvent(eventName: String: body: Any) {
self.sendEvent(withName: eventName, body: body)
}
}
This works perfectly and fires my callback listener that is in my javascript code when I call the emitEvent method like the following, its an altered snippet from
https://github.com/cotyembry/CastRemoteNative/blob/7e74dbc56f037cc61241f6ece24a94d8c52abb32/root/js/Components/ChromecastDevicesModal.js
From the javascript side
import {
NativeModules,
NativeEventEmitter
} from 'react-native'
//here I bring in the swift class to use inside javascript
var NativeMethods = NativeModules.NativeMethods;
//create an event emitter to use to listen for the native events when they occur
this.eventEmitter = new NativeEventEmitter(NativeMethods);
//listen for the event once it sends
this.subscription = this.eventEmitter.addListener('test', (body) => { console.log('in test event listener callback', body)});
NativeMethods.sendEventToJSFromJS() //call the native method written in swift
I simply have the sendEventToJSFromJS method invoked on a button press in javascript
Again, this works and the console.log('in test event listener callback', body) code works and runs on the javascript side
My Issue where this does NOT work:
If I was to do the following inside the swift file after defining the class, this would not work:
var nativeMethodsInstance = nativeMethods()
nativeMethodsInstance.sendEventToJSFromSwift()
Why? Because the following error is thrown:
Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'bridge is not set. This is probably because you've explicitly synthesized the bridge in NativeMethods, even though it's inherited from RCTEventEmitter.'
So, when creating an instance of NativeMethods, versus not... what is the difference?
For additional information:
Objective-C gets the same bridge not set issue when I write these same snippets of code in .h and .m files instead of in .swift files
I found where the error message is getting printed in the native code, but it just has the variable
_bridge
and is checking to see if it is nil
The files are this error comes from is:
RCTEventEmitter.h
RCTEventEmitter.c
here is the full snippet of RCTEventEmitter.c
- (void)sendEventWithName:(NSString *)eventName body:(id)body
{
RCTAssert(_bridge != nil, #"bridge is not set. This is probably because you've "
"explicitly synthesized the bridge in %#, even though it's inherited "
"from RCTEventEmitter.", [self class]);
if (RCT_DEBUG && ![[self supportedEvents] containsObject:eventName]) {
RCTLogError(#"`%#` is not a supported event type for %#. Supported events are: `%#`",
eventName, [self class], [[self supportedEvents] componentsJoinedByString:#"`, `"]);
}
if (_listenerCount > 0) {
[_bridge enqueueJSCall:#"RCTDeviceEventEmitter"
method:#"emit"
args:body ? #[eventName, body] : #[eventName]
completion:NULL];
} else {
RCTLogWarn(#"Sending `%#` with no listeners registered.", eventName);
}
}
Where does this _bridge value get set and how does it get set so I can know, in the cases where it is failing how to set it
I found the following also in RCTEventEmitter.h
#property (nonatomic, weak) RCTBridge *bridge;
In the error that is given it mentions the bridge is inherited in the RCTEventEmitter, so is this maybe an issue with the weak part to the bridge property?
Or do I need to change my strategy in how I'm doing this all together?
I know it probably has to be something to do with me not fully understanding the
#synthesize bridge = _bridge;
part of the code and all the languages being mixed in doesnt help much lol...
This is really hard, so any help would be much appreciated!
Thanks so much for your time
here is a link to the full project when the project history code represented the code from my question above (since I have since made changes to the project):
https://github.com/cotyembry/CastRemoteNative/tree/7e74dbc56f037cc61241f6ece24a94d8c52abb32
I figured it out
Warning: this solution uses a deprecated method react native method - I could not figure out how to "properly" inherit from the RCTEventEmitter and send an event... every time I tried to the _bridge would end up being nil
Make sure Swift is bridged to Objective C (if you're using swift to send the event to javascript)
Do Not create instances of the exported Native modules (whether they be written in Swift or Objective C)
Let React Native's underlying implementation do this and for each and every class that needs to send an event, export that particular Native Class Objective C Implementation code or Swift code (the Native Module) to React-Native. This allows the javascript to be able to listen to the event
var publicBridgeHelperInstance = PublicBridgeHelper() //instantiate the the objective c class from inside the .swift file to use later when needing to get a reference to the bridge to send an event to javascript written in react native
#objc(DeviceManager) //export swift module to objective c
class DeviceManager: NSObject {
#objc(deviceDidComeOnline:) //expose the function to objective c
public func deviceDidComeOnline(_ device: GCKDevice) {
//imagine this deviceDidComeOnline function gets called from something from the Native code (totally independent of javascript) - honestly this could be called from a native button click as well just to test it works...
//emit an event to a javascript function that is a in react native Component listening for the event like so:
//1. get a reference to the bridge to send an event through from Native to Javascript in React Native (here is where my custom code comes in to get this to actually work)
let rnBridge = publicBridgeHelperInstance.getBridge() //this gets the bridge that is stored in the AppDelegate.m file that was set from the `rootView.bridge` variable (more on this later)
//(if you want to print the bridge here to make sure it is not `nil` go ahead:
print("rnBridge = \(rnBridge)")
//2. actually send the event through the eventDispatcher
rnBridge?.eventDispatcher().sendAppEvent(withName: "test", body: "testBody data!!!")
}
}
in AppDelegate.h put (additionally to the code that was already in the file)
#import "YourProjectsBridgingHeaderToMakeThisCodeAvailableInSwift.h" //replace this with your actual header you created when creating a swift file (google it if you dont know how to bridge swift to objective c)
#interface PublicBridgeHelper: NSObject
-(RCTBridge*)getBridge;
#end
in AppDelegate.m put (in addition to the code that was already in the file)
#import <React/RCTRootView.h>
RCTBridge *rnBridgeFromRootView;
#implementation PublicBridgeHelper //this is created to SIMPLY return rnBridgeFromRootView defined above over to my Swift class when actually sending the event to javascript that defines a react native Component
-(RCTBridge*)getBridge {
NSLog(#"rnBridgeFromRootView = #%#", rnBridgeFromRootView);
return rnBridgeFromRootView;
}
important - also make sure to add the following line of code to the Objective C .h's bridging header to make this PublicBridgeHelper definition available to be used in the .swift code
#import "AppDelegate.h"
finally,
now to show you how to set the rnBridgeFromRootView variable used in AppDelegate.m (that gets returned and used in the .swift code right before sending the event to javascript)
open AppDelegate.m and in the method body of
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { ... }
include the following after the line of code that instantiates the rootView variable
i.e. after the line that probably looks like
RCTRootView *rootView = [[RCTRootView alloc] initWithBundleURL:jsCodeLocation moduleName:#"YourProjecNameProbably" initialProperties:nil launchOptions:launchOptions];
add:
rnBridgeFromRootView = rootView.bridge //set the bridge to be exposed and returned later and used by the swift class
Now to explain the publicBridgeHelperInstance.getBridge() part that is in the .swift file
publicBridgeHelper is an instance of an objective c class which allows the swift class ability to get a reference to the react native bridge
If you are still having problems understanding my answer after reading this I made a video over it and you can watch it here:
https://www.youtube.com/watch?v=GZj-Vm9cQIg&t=9s
I am writing a COM object for JavaScript consumption. JavaScript code is turn runs in an hosted WebBrowserControl. I need to fire some events from COM object to JavaScript, the excellent guide to which at Dr. Dobbs
e.g.
I have following in my *.idl
IJSCallback
{
void Listen(IDispatch* pJSMethod);
}
JavaScript methods are received as IDispatch* in C++ code, which is to be stored for calling it later, from another thread.
No matter what method for marshaling is used (CoMarshalInterThreadInterfaceInStream or IGlobalInterfaceTable) the event firing thread is able to call JavaScript function only once. After that IDispatch::Invoke() returns E_ACCESSDENIED!
sample JavaScript code
var server = new ActiveXObject("prog_id")
var.Listen(function(ip_add) {
// ip_add from COM object
});
the C++ thread is pretty straight forward.
// called from JavaScript
CMyObject::Listen(IDispatch* pJSMethod)
{
// IStream* m_pStream;
CoMarshalInterThreadInterfaceInStream(pJSMethod, IID_IDispatch, &m_pStream);
}
// called from internal C++ thread.
CMyObject::FireEvent()
{
// IStream* m_pStream;
// IDispatch* m_pJSMethod;
CoGetInterfaceAndReleaseStream(m_pStream, IID_IDispatch, (LPVOID*)&m_pJSMethod);
HSREULT hr = m_pJSMethod->Invoke(...); // hr = S_OK, call is received in JavaScript
hr = m_pJSMethod->Invoke(...); // hr = E_ACCESSDENIED, call is not received in JavaScript
}
is this expected behavior? or something wrong in code?
Fixed. As mentioned in comments alert() works but document.writeln() doesn't. That is because document.writeln() resets the current document including scripts elements, use document.createElement(), document.createTextNode() and friends to modify current loaded elements.
This could be common knowledge for those familiar with HTML/JavaScript, for rest of us it can be a real deal.
Let me explain the whole problem. I was trying to avoid writing this as it could be a long explanation.
I am working with a tool called Lectora. This is an authoring tool which generates HTML pages and SCORM compliant packages to be deployed to the LMS.
When I insert a button in the Lectora, the code that is generated is something like this...
<script>
// some code here...
button63 = new ObjButton('button63', ....);
button63.setImages('images/btn_next_en.png','images/btn_next_en.png','images/btn_next_mouseover_en.png');
button63.build();
button64 = new ObjButton('button64', ....);
button64.setImages('images/btn_back_en.png','images/btn_back_en.png','images/btn_back_mouseover_en.png');
button64.build();
button65897 = new ObjButton('button65897', ....);
button65897.setImages('images/btn_submit_en.png','images/btn_submit_en.png','images/btn_submit_mouseover_en.png');
button65897.build();
// some more code here...
</script>
So I try to write:
<script>
var arr_buttons = [];
for(var i in window)
{
if(window[i] typeof object)
{
if(window[i] != null)
{
if(window[i] instanceof ObjButton)
{
arr_buttons.push(i);
}
}
}
}
alert(arr_buttons.length); // gives me 845 in IE11 and it gives me 44 in IE8
</script>
And when I check the contents of arr_buttons in console or by any other method, I do not find button65897 of any other button object in it. Which makes me think that it is not iterated at all!! This is my problem.
ObjButton is a Lectora created javascript object and I cannot edit it.
Now, I have set the language option in another variable and depending on the variable value for language, I want to get hold of the object 'button65897' and change its images. Now I am finding it difficult to get hold of 'button65897' in IE8.
Isn't there any way to get hold of the object 'button65897' in IE8?
Most of the examples you find on the web, of using javascript from ASP.NET pages puts the javascript in the markup file (*.aspx). This is, of course, a really bad idea(tm), for all but the simplest uses of javascript.
What we want, of course, is to wrap the javascript up into a class, and to instantiate an instance of that class and tie it to the code-behind.
Microsoft provides a framework for doing this for user controls and server controls, in its IScriptControl interface. This allows a developer to create a javascript "component" - to define a javascript class in a *.js file, to include the *.js file on the page that contains the control, to instantiate an instance of the component, to set variables in the component from values in the code-behind, and to get a reference to the component in javascript on the client side.
The thing is - IScriptControl only works for user and server controls. It cannot be used to instantiate javascript objects at the page level.
So - how do people do this? We have some patterns we've been using, that seem to work. I was wondering what everyone thought of them, and what other people were using.
We start by defining a javascript class in a *.js file. In the code-behind, we create a loadJavascript() function, that we call from Page_Load on initial load or full postback (but not on partial postbacks).
In loadJavascript(), we include the *.js file with ScriptManager.RegisterClientScriptInclude(), and then construct a bit of javascript that instantiates an instance of the class, assigns a reference to a known name, and registers the object's initialize() and dispose() methods as handlers for window.load and window.unload.
E.g.:
string url = this.ResolveUrl("./FooBar.js");
ScriptManager.RegisterClientScriptInclude(this, this.GetType(), url, url);
string script = #"
if (typeof {0}_obj == 'undefined')
{0}_obj = {{}};
{0}_obj.fooBar = new FooBar();
Sys.UI.DomEvent.addHandler(window, 'load',
function()
{{
{0}_obj.fooBar.initialize('{1}', '{2}');
}}
);
Sys.UI.DomEvent.addHandler(window, 'unload', {0}_obj.fooBar.dispose);
";
script = String.Format(script,
new object[]
{
this.ClientID,
this.foo.ClientID,
this.bar.ClientID
});
ScriptManager.RegisterStartupScript(
this, this.GetType(), this.ClientID, script, true);
We construct an object name in the global namespace, based on the ClientID of the page, if we haven't already. We add an instance of our new class as a member of our global object. We add a window.load handler that calls our object's intialize() method, passing the clientIDs of the controls on the page that the object's methods need to access. And we add a window.unload handler that calls our object's dispose() method, that does whatever cleanup that is necessary.
This seems to be working, for us. We've used this pattern on a number of pages, some of which did significant amounts of partial-postbacks, without any problems.
I was wondering, first, what people thought of the pattern.
But more, I was wondering if we'd been reinventing the wheel, and if there were other approaches to dealing with the issues we were addressing, that we weren't aware of.
Anyone have any better ideas?
But more, I was wondering if we'd been reinventing the wheel, and if there were other approaches to dealing with the issues we were addressing, that we weren't aware of.
I think this the most good approaches, I use the same way some years now with out any problem in very complex javascript code. I do not see why you question your self :)
The idea is this you follow, now maybe there are some variations, maybe I not call the unload, nether create an object to keep the foobar and call the foobar rightway, but the idea is the same. I also check if the Javascript file have been loaded...
string script = #"
if (typeof (FooBar) != "undefined") {{
var {0}fooBar = new FooBar();
Sys.UI.DomEvent.addHandler(window, 'load',
function()
{{
{0}fooBar.initialize('{1}', '{2}');
}}
);
}}