I am trying to build an app using Extjs 4.1. In general: it is a viewport with a tree panel on the west and a center panel that it is actually a tab-holder panel. When a user clicks on a tree node a tab is populating the center view. I had set an attribute in the tree panel that after selecting a node it gets deselected (deselectAll). The reason for this is that the user can open many tabs from different places (e.g. within each tab). But, when I set the above attribute it is producing an error (the “data” is undefined). The data that is undefined is the data related to the tree node. So, the question concerning selection model:
How can I address this problem (a solution may be to select the fist node, but I don’t want it)?
As for the history utility, I need to implement browser back button. Especially I want to disable browser’s refresh button. If user opens let’s say 15 tabs and accidentally click on browser refresh or “F5” he/she will lose everything. I had tried many things but with no luck. I am unable to understand “Ext history util”. So,
Is there any good example out there?
Could anybody guide me on how to do it?
Notice that the application is built respecting the new “MVC” architecture.
Stopping the refresh event is pretty easy - providing that your page has the focus. E.g.:
Ext.getDoc().on('keypress', function(event) {
if (event.getCharCode() == event.F5) {
event.stopEvent();
console.log('you stopped the refresh event');
}
});
If your page doesn't have the focus then there is nothing that can be done -- but most of the time your page loses the focus when a different browser tab is opened so F5 would be refreshing that one instead anyway.
I'm still trying to wrap my wits around the first part of your question, but I thought I would share that.
EDIT
Instead of trying to stop the default browser behavior (something which you can only do on a very limited basis), you should look into state management. ExtJS supports it on many components. Here is the ExtJS example.
Also here is the example of controlling browser history.
Related
How can I prevent the showing of the Next or Done buttons of the Android VKB in a Codename One app?
Currently, for my app, they are a mess: the next button of the VKB doesn't focus the next field, but the previous. After tons of trials, I didn't find a way to make them working correctly (but there are fine on iOS and on the Simulator). I also tried to override the Layout.overridesTabIndices(com.codename1.ui.Container) and Layout.getChildrenInTraversalOrder(com.codename1.ui.Container) methods in the Form, but nothing changed on Android.
I supposed two possible causes: the use of a Form inside a Form or, more probably, the fact that I replace all the TextFields and Pickers in the same Form (and other components). Maybe the fact that the inner Form is deeply changed results in a confusion for the Android mapping of the "next" button.
That's why my request: because I didn't find a way to make the "next" button useful, I'm asking how I can avoid that it's been shown.
Thank you
Nesting forms would probably mess with the focus traversal/tab order.
Normally you should be able to override public TabIterator getTabIterator(Component start) to return a blank iterator. I'd suggest doing the same for both the parent and child form to disable the "next" feature.
I'm making an accessible web application. One of the feature is a button that allows users to scroll to a certain section of the page. I'm using window.scrollTo(x,y) for this functionality.
Now testing my application using the built-in Mac VoicerOver, I found that although I can click on the button and scroll with no problem, after scrolling, VoiceOver doesn't read anything. Instead I have to click on the mouse one, or use the keyboard equivalents to make it read the content that's on the screen after scrolling.
I'm afraid that some users may not realize that they need another click after clicking on the button. I have two possible solutions:
When the screen reader read the button, it also tells the user that if they want to go to the livechat, they need to click again after clicking on the button. I know how to implement this one, but it looks verbose and dumb.
Change my code so that VoiceOver will read the content after scrolling. I don't know how to implement this one.
The content I would like the screen reader to read is wrapped in a tag.
If you are only scrolling the page, then most screen reader users will not care that you scrolled. With limited or no vision, whether the screen scrolls or not does not matter because the screen cannot be seen.
However, if you are scrolling the page in order to put a certain element into view, then that would benefit screen reader users too.
It sounds like you're trying to do the latter:
allow users to scroll to a certain section of the page
In that case, you also need to put the keyboard focus on that element via the focus() javascript call. Moving the focus will cause VoiceOver to read that content. But to move the focus to a natively non-focusable element (such as an <h2> or a <section> or <p>), the receiving element will need tabindex="-1".
<h2 tabindex="-1" id="myh2">some heading</h2>
and then somewhere you'd have this javascript:
var element = document.getElementById("myh2");
element.focus();
We're developing a simple app with the sencha framework
The app consist of a few tabs( a tabPanle with bottom tabBar) and the switching between tabs works perfectly when we use it as it is on the sencha docs, alas when no live data is present.
When we add stores within the single tabs, functionalities breaks, tabs stop switching and every time one clicks a tab to change the view, a flickering appears, the default tab is loaded again(from the chrome console we can see that all the remote data request of the loginView get reissued) and the only tab that remain visible to the user is tab[0].
app.js --> http://pastebin.com/S9qaNfij
mainView.js ---> http://pastebin.com/uiG2E0AW
controller.js ---> http://pastebin.com/8MTfxC85
This was created with senchaArchitect, that btw is awful and quite useless if not to work visually with the components.
here is a little movie of the thing happaning.
http://youtu.be/OVOSOWhMZeE
What are we doing wrong?
I think it's your button listener, it seems that it might be being triggered on even the tab panel button taps. I would try giving your button a unique ID and then create a ref and an action to login based on that ID.
I should create ExtJs4 app, which should have main menu, and each menu item should open a new page with different url, so if the user copies the url and pastes on other browser tab, the app should open that menu item.
I want to use ExtJs's recommended MVC architecture, but I don't know how I can use it with multiple pages/urls. All their examples are using single page.
One option is to reload the page each time when the user clicks on particular menu Item, so every url/menu item/page will be separate ExtJS app with it's MVC. But I think this approach has drawbacks, since the page will be reloaded every time and it's not good for performance. Also it's causes difficulties in reusing of components (common models, stores and views for different pages ).
So I would like to have one single app for all pages, but I don't know is there any solution to have different urls for different views (in my case: for different menu items).
Or is there another approach for such applications?
You would probably want to use a Viewport, and make the Center Region a Container.
The Center Region Container would usually have a Card or Tab layout.
When the user navigates to a new view (Component), you add that view to the Container, and make it active.
The big mistake is to change the URL first. You don't want to do that.
You want to navigate, and then set the URL if the navigation was successful. You should probably not use ExtJS's History component, as it is incorrectly implemented. I would recommend using HTML5 pushState.
You should make sure your navigation system works without changing the URL bar too.
I would recommend reading up on Navigation in Microsoft Prism, WPF, and Silverlight, as there is more documentation there, and then apply that to ExtJS.
http://msdn.microsoft.com/en-us/library/gg430881(v=pandp.40).aspx
Here is an example Navigation process:
call app.requestNavigate('contacts/5'); you would add this yourself.
you parse this fragment to:
navigationContext = {
fragment: 'contacts/5',
xtype: 'contacts-form',
parameters:{
id: 5
}
}
OPTIONAL: If using forms:
get active item from the navigation region (your center region). if exists, call confirmNavigationRequest(callback) . you will need to add this method or event.
if callback(true), proceed with the navigation. this allows the user to cancel a navigation, if say the form is "dirty"
END OPTIONAL
the easy way is to then create a new widget of navigationContext.xtype, add it to the navigation region, then call setActiveItem(widget). destroy the previous active item if it existed.
then call history.pushState(null, null, navigationContext.fragment)
then raise a 'navigatedto' event on the view, passing the context, and you can load the data from there.
More advanced scenarios include:
keep the previous component alive if you expect to return to it. add a keepAlive property and if true, don't destroy when add new components to container.
search the container and ask each component if it wants to handle the current navigation request (for example if a form loaded with contact-5 was already hidden in your navigation region, or if you want to re-use a form)
I have a really strange issue relating to how I handle navigation in an application, and that application now being rejected from AppHub (after being successfully approved a number of times on the same code base... grr)
currently I am capturing the first navigation of the application and routing it an "add item" page in the App.cs using the example found here
the user then adds an "item"
the user is taken to the "main" page again, but stay there are there is now 1 "item" to show in a list
the user then can view a "detail" page of this item where they can select to delete the current item. when they do that I redirect them to the "main" page again.
this navigation then fires the same thing that happened in step 1
and they are routed to an "add" page
the problem with the above process, is that if the user hits "back" on the routed page in step 5 they don't go anywhere as they are routed back to the current page (because there are no items on the page previous and this fires the app.cs routing event to take them to the add page). if I did allow for them to go back, the actual first page they would be able to go back to is 3 nav steps back, when they first added the item - as they are on the "add item" page already, this would be pointless.
The apphub store testers say that in this instance, the application should close. I really don't know how the f&*k I am meant to make this happen, as there is no "go back until close" action I can call...
thoughts?
When the user decides to "delete" the current item, you shouldn't navigate forward to the main page, leaving the deleted item in the navigation stack. You should navigate back to the main page. That way the navigation stack will be empty, and if they navigate back again, the app will close.
(The same is true at step 3, of course - when the item is added, navigate back to the main page. You don't want the "add" page as part of the navigation stack; that action has been completed.)
The single best advice I read on WP7 navigation was "if you don't have to, don't use it." I've almost stopped using it all together and just use "MainPage.xaml" for loading/unloading user controls that do this kind of stuff. I completely control the Back button as needed. It has saved me so much headache. The important thing to realize is that the Navigation pages are really just mimicking a website and it's pages - many apps do not fit that paradigm (as they are apps, not websites). So, if you don't have to use Navigation, don't use it.
So in your case, if you just managed everything on MainPage.xaml, you would use a number of If/Then statements in OnBackKeyPress and if one meets your criteria, do an e.Cancel = true; and show/load/etc. your thing. If not, let the app navigate out of itself - i.e. exit.
For tombstoning, just let the OnNavigatedTo in MainPage.xaml handle loading the right user control received from tombstoned information retrieved from Application_Activated.