I know that I can use local storage, cookies and postMessage but all these methods only accept simple types. I want to pass objects and lists directly to the other window.
I found a similar question but using javascript. I'd like to do something just like Victor pointed in the following link.
Can I pass a JavaScript variable to another browser window?
Trying anything similar in Dart gives me a warining even before running.
var popup = window.open('popup.html', '');
popup.variable = localVariable; //warning here
Passing objects is not possible.
You can serialize to JSON to make it a simple type and pass it using postMessage and then deserialize.
Lists and maps containing only simple types should work with postMessage.
Related
I am trying to call a method of a class that I only know by name as a String. Now therefore I would need a ClassMirror of that class that allowes me to instantiate an instance. However, creating ClassMirrors seems to be only possible by entering a type using reflectClass(Type) or by passing an already existing instance of that class into reflect(dynamic). So these aren`t helping if I only have a String.
In Java you can do this pretty easily, by calling Class.forName(String). Then you would get a Constructor instance, make it accessibly and call it.
Does anyone know if this is even possible in dart? What seems weird is that once you have a ClassMirror you can access fields and methods by passing symbols, which can be created by Strings.
You can put a specific list of strings to map to a specific list of closures to create a new object with specific parameters.
But you can't get a reflection without using dart:mirrors, which is being deprecated, and also had a negative impact on tree shaking to get the payload size down.
In general, you're invited to look at the package:reflectable to achieve most of what you'd want out of dart:mirrors, using source-to-source builders.
According to the Microsoft documentation, one can create instances of the COM objects using both the ActiveXObject() and the WScript.CreateObject() functions. It seems like the lines
var objXL = new ActiveXObject("Excel.Application");
and
var objXL = WScript.CreateObject("Excel.Application");
are identical. Is this a true assumption? and if not what is the difference? Examples to show the difference would be highly appreciated.
P.S. The post this has been flagged as a duplicate to is about the difference between VBScript's CreateObject() method and JScript's WScript.CreateObject(). It answers mention the JScript's ActiveXObject() constructor with no further elaborations.
Are they the same?
The short the answer is Yes they are the same (in the sense they perform the same job of instantiating an automation object).
Basically unlike VBScript which has the global function CreateObject() there is no such equivalent in JScript which was based on ECMAScript 3rd Edition. So, Microsoft added its own extension ActiveXObject which does the same job as CreateObject.
Both languages can be hosted in the Windows Scripting Host which gives them access to WScript.CreateObject() which is another method that does exactly the same function but only in the context of the WScript object that is only available through the Windows Scripting Host.
Following up
There has been some debate about whether they are the same, I still stand by my original answer they are the same. However, I will concede that I was comparing VBScript CreateObject() and JScript new ActiveXObject() not Wscript.CreateObject() (which is slightly different).
Let's be clear though, all these functions and objects serve the same purpose which is to instantiate an automation object (COM). To back this up here is the official description of each;
WScript - CreateObject() Method
Creates a COM object
JScript - ActiveXObject Method
Enables and returns a reference to an Automation object
VBScript - CreateObject() Function
Creates and returns a reference to an Automation object
If they were completely the same what would the point of them be? We already have language-specific automation instantiation methods, so what would the point of Wscript.CreateObject() be?
The difference is when called with a second parameter it allows you to specify a prefix that will use to distinguish event handlers for that COM object.
Here is an example taken from this answer that shows how the second argument is used to set a prefix of objIE_ that will then be used to prefix any event handlers associated with that COM object, in this case, the InternetExplorer.Application object.
// JScript
var objIE = WScript.CreateObject("InternetExplorer.Application","objIE_")
objIE.Visible = true
while (objIE.Visible){
WScript.Sleep(500);
}
function objIE_NavigateComplete2(pDisp, URL){
WScript.Echo("You just navigated to", URL)
}
function objIE_OnQuit(){
boolBrowserRunning = false ;
}
It allows an Internet Explorer instance to be opened and the URL navigated to captured through the bound event, once the Internet Explorer Window is closed the script will end.
So while not identical they do perform the same function of instantiating an Automation (COM) object.
Useful Links
Answer to What is the difference between CreateObject and Wscript.CreateObject?
It seems when I call Gdk.Seat.grab() in GJS I get an error:
Gjs-WARNING **: JS ERROR: TypeError: Gdk.Seat.grab is not a function
This function and class is listed in the GJS Docs, but maybe I'm calling it wrong? If I call typeof on Gdk.Seat.grab it comes back undefined. Is this not possible, or is there another way I can grab focus in this way?
My use case is gathering a keybinding from a user, for which I can use Gtk.CellRendererAccel, but I would prefer not to use a Gtk.TreeView. The docs say about CellRenderers that:
These objects are used primarily by the GtkTreeView widget, though they aren’t tied to them in any specific way.
and...
The primary use of a GtkCellRenderer is for drawing a certain graphical elements on a cairo_t.
Which implies I could use it outside of TreeView, but with no hints as to how.
grab() is a method of Gdk.Seat, so you need a Gdk.Seat object to call it on. It looks like you're calling it as a static method, Gdk.Seat.grab(). So, you'll need something like Gdk.DeviceManager.get().get_default_display().get_default_seat() or you can get a Gdk.Seat object from a Gdk.Event.
It's not clear from the described use case what you are trying to do with the grab, but there may be an easier way to accomplish it.
I can get parent window name in Javascript, and don't know how to do it in Dart.
I have tried to down cast window.opener to window in Dart, but it throw exception.
According html5.1 nightly, should we expect it implemented as window basic attribute?
//js version:
window.opener.name
//dart version:
(window.opener as ?).name
For a popup window.opener can be used and for an iframe window.parent. Both return a _DOMWindowCrossFrame which do not support name as they implement WindowBase. That's also the reason why you can't cast to window. You should use postMessage to communicate and exchange information.
See also this implementation note: Its fields and methods can only be accessed via JavaScript.
An alternative approach is to use dart-js-interop
import 'dart:js' as js;
print(new js.JsObject.fromBrowserObject(
js.context['window'])['opener']['name']);
There is currently no way in Dart. Access to the windows object is intentionally denied for security reasons. According to comments on related bug reports they consider changing it because it can be worked around using dart-js-interop anyway.
Is it possible to use the state of a javascript global variable in the "test=" of a tag? If so how would I access that variable since ${} is usually to evaluate variable sent from the Controllers.
Try using a jQuery function in conjunction with JSON data returned from your controller. You may be able to accomplish what I think you need.