Hi we have a gwt app hosted on google app engine.
In one of the page bound to an entry point class (using root panel id) we call a rpc service to get some data.
The problem I am observing is that when even the home page is loaded that time the entry module class bound to another page gets instantiated and thus the service is called un-necessary.
any options to defer this behavior until the page is opened?
You can load the data for the page in the onLoad method instead of in the constructor so that the data isn't loaded till after the widget is attached to the DOM.
Moving the code under the clause like shown below fixed the issue
if(RootPanel.get("login") !=null){
//moved here
}
Related
I have a Home Page, inside that I have created one component RecentlyViewedProductComponent.
My problem is:
when I navigate to /home by using
this.router.navigate(['/home']);
the ngOnInit() inside RecentlyViewedProductComponent is not working. When I close the app and open it again, that only it is working .
How to solve this problem?
It sounds like you are not using the right lifecycle event.
Have you looked at the documentation here:
https://ionicframework.com/docs/angular/lifecycle
It says that ngOnInit() is:
Fired once during component initialization. This event can be used to initialize local members and make calls into services that only need to be done once.
If you want it to be called every time you navigate to the home page then you want to replace this with something like ionViewWillEnter():
Fired when the component routing to is about to animate into view.
There is actually some guidance at the end of the docs page that you might find interesting which explains when to use each life cycle method.
I am creating a function that calculates a page loading time for each page of my Ionic 3 App (I use lazy loading). However, I am currently stuck in issues:
When does the page start creating HTML?
When does the page finish creating HTML?
When does the page complete downloading all resources on the page (image, etc …)?
Can anyone give me advice?
One thing to look at is https://blog.ionicframework.com/navigating-lifecycle-events/ this contains the ionic life-cycle eg. ionViewDidLoad(): Fired only when a view is stored in memory. This event is NOT fired on entering a view that is already cached. It’s a nice place for init related tasks.
Ionic 3's pages are also angular components so I'd imagine the another thing to look at is the component hooks. These methods are fired when in the stages of the component life cycle.
https://angular.io/guide/lifecycle-hooks
https://www.intertech.com/Blog/angular-component-lifecycle/
eg. ngAfterViewInit(){ stopTimer() } //this method is fired once Angular initializes component and child component content
To achive what you want you could have a provider that both pages link to. When you change page start a timer and stop it using ngAfterViewInit() or other more appropriate hook.
I am wondering why binding a button inside the Loaded event in WPF page does not work and will only work after navigating to another page, and going back.
I have an inventory app and on the main page, most of the ViewModel are called because of a Back button which goes back to a specific lists and what causes that is, it will start binding the even if that command is not for that page and it will also load the collections for other pages.
So I used Loaded page event to call the necessary methods to populate the lists and also start binding commands for this specific page. I also used Unloaded page event for clean up like unsubscribing to some CRUD events.
The problem now though is, buttons does not get binding in Loaded page event. I do not know why..
I have made a miniature app to demo the problem. It can be downloaded here
(full source code included)
https://www.dropbox.com/s/qzumzyicuvrktsi/ICommandTest.zip?dl=0
This is because your views are not getting notified about the change of Command_ShowAddWindow and Command_ClickMe. Let me explain:
When your Page constructor is first run the bindings to your commands are initialized and transferred to the view, but by that time your commands are null, so the view binds both buttons' commands to null.
Then when your Loaded event is fired the commands are initialized, but the view is not getting notified about it, so it keeps command bindings to null.
The solutions to the problem are:
You manually call RaisePropertyChanged to notify the view about commands change when you initialize them:
void InitCommands()
{
Command_ShowAddWindow = new RelayCommand(Command_ShowAddWindow_Click);
Command_ClickMe = new RelayCommand(Command_ClickMe_Click);
RaisePropertyChanged("Command_ShowAddWindow");
RaisePropertyChanged("Command_ClickMe");
}
Or you initialize your commands in your ViewModel constructor before DataBindings are initialized:
public ViewModel_Page1()
{
InitCommands();
...
}
I can't wrap my head around this issue I've been experiencing, or perhaps I'm missing some crucial point here. I jotted down this sample app on ionic playground, it is of course a simplified version of my app.
Basically I have a tabbed layout with two views which share a common datasource of items (in my app it's a sqlite db table); the first view displays items in a certain state whereas the other tab display the remaining items (in my example I've used the TODO list metaphor).
Each tab has a child state which I refer to as 2nd-level state (assuming level 0 is the abstract tab state. These two 2nd-level states are defined separately but share a common controller and template.
I cannot for the life of me understand why these two states aren't being navigated to when I click on a list item from either of the two lists (1st-level state views).
NOTE: In the ionic playground no error is thrown in the console, but I can't quite tell what is going on in terms of state URLs. But when I test my actual app (where the problem is the same) in a browser I can see the URL changing to #/tab/tasks/xxxx or #/tab/completed/xxxx but template is not loading. Upon googling I came across several SO questions:
Ui-router URL changes, nested view not loading
In Angular ui-router nested state url changes,but template is not loading
UI-Router: URL changes, but view is not loaded
Angular Router - Url changes but view does not load
URL changes but view does not hcange
Angular UI-Router : URL changed but view isn't loaded
but the answers provided therein haven't worked for me (tried, as per the last one I listed, to add the # sign after the view name in the child states, but to no avail).
Kinda stuck, would really appreciate some input! Cheers.
Managed to get it working following this answer; I had previously tried simply appending the # character after the view name in nested states but it turns out the trick was to append #tab, where tab is the name of the top-level abstract state. I updated my fiddle on ionic playground. Cheers to you all.
I am currently working on a GWT project where I am displaying an HTML file within an iframe in my application. This HTML file is actually being written to as it is getting displayed, and I am hoping to be able to reload the frame so that the changes made to the HTML file are reflected on screen. I am able to do this two different ways that both work when running in development mode, however neither seem to work when the project is deployed.
The first method I tried was setting the frame's URL to itself:
frame.setUrl(frame.getUrl());
The second method I tried using JSNI:
public native void refresh() /*-{
if($doc.getElementById('__reportFrame') != null) {
$doc.getElementById('__reportFrame').src =
$doc.getElementById('__reportFrame').src;
}
}-*/;
When deployed, the frame gets displayed in a Window, and when the file is finished being written to, a call to either of these refresh methods is made, and the frame refreshes to contain the finished HTML file. When I am deployed, the call to refresh does not reload the contents of the frame, however if I bring up the frame's context menu (in Firefox), then go into 'This Frame', and click Reload, it successfully reloads the frame to contain the finished HTML file. I have tested this on multiple versions of Firefox without any luck.
Does anyone have any suggestions? Why would the behavior be different from one mode to the other?
Thanks.
wow, google is really fast with his search^^
You can use some JSNI to do this. Create a method such as
protected native void reloadIFrame(Element iframeEl) /-{
iframeEl.contentWindow.location.reload(true); }-/;
Then call it with your iFrame element
so your question you posted twice was already answerd here
http://groups.google.com/group/google-web-toolkit/browse_thread/thread/64aa7712890652d3
We had a requirement where one GWT application(parent) had another GWT application(child) loaded in an iframe. The child application had to refresh the iframe after it performs certain DB operations. We used JSNI to accomplish the same.
private native void refreshChild(String url)/*-{
$wnd.location.href=url;
}-*/
In case, if the child frame needs to be redirected to another webpage, the url can be modified accordingly.
We did try to use the reload() method, but it did not help.
The above piece of code, of course needs to be written in the child application.