Writing event handlers in extensions in AX7 - events

I am working in Dynamics AX7 form development. I have to write code in 'Clicked' method of a button, but there is already some 'Sys Layer' code in 'Clicked' method. I have to apply some conditions on it. But I don't want to do 'over-layering', i have to do it with Extensions, but if I write code in onClicked event, the problem is, my code runs before or after the sys-layer code, but i need to apply some conditions on that sys-layer code.
my question is, can we achieve this logic with extension event handlers ? I have already done it with over-layering, but I need to do it with extensions. So is it possible to do it with extensions ?
Code is added below.
void clicked()
{
super();
// My logic will be written here
if(result == true) //This is my code, based on above logic I applied this check
{
// start of sys layer code
remainSalesPhysical.realValue(0);
remainInventPhysical.realValue(0);
if (formCtrl)
{
formCtrl.cancelLine();
}
element.closeOk();
// end of sys layer code
} //this is my code
else //this is my code
{ //this is my code
error("Some error message"); //this is my code
} //this is my code
}

Yes and no. If it's just a button then the super() doesn't really do anything, so you can do a pre event handler.
If it's a menu item button, where the super() calls a class, then you would do a post event handler to the class and not the button, so that way your logic runs immediately after the super() call.
And in your class, you can do something like formRun = _xppPrePostArgs.getThis() and then if (formRun.name() == formStr(SalesTable)) or any number of things if the class has multiple entry points.

I have searched about it and what i concluded so far is that, we can't do it 100% without overlayering. We have Pre and Post events but these are unable to cater the above mentioned problem, May be in future we will have some more specific way of doing this, but for now we have three options.
Do overlayering as we did in AX 2012 (which is not recommended)
Do it With Delegates (even with delegates we're restricted to do some overlayering, but it is recommended way)
You can also hide that button and replace it with your own button, but it will work only for Form Controls, we can't do it for methods, as you can't avoid calling them.
I solved my problem using delegates.
Here is a Helpful link I found about it and it helped.
https://ievgensaxblog.wordpress.com/2016/05/01/ax-7-how-to-override-form-data-source-field-methods-without-overlaying/

Related

How to add an event listener to a Kendo UI view?

$('#my-view').on('show', showHandler)
Doesn't work. Using data-show is not an option either because the code that sets/unsets the event is within class that is instantiated later. Also creating the view programatically and passing in the event handler doesn't work because I need to set the event on/off at different times.
Is this not possible with kendoUI? If not, why? This seems like such an incredibly obvious feature to relay those events to the element themselves similar to what is possible with jquery ui widgets.
This works:
var view = $('#my-view');
var widget = kendo.widgetInstance(view);
widget.bind('show', showHandler);
Better answer, just delegate the events yourself so the code in the question actually works:
<div data-role="view" ... data-show="onShow">...</div>
and
function onShow () {
this.element.trigger('show');
}
Now the it works :). The problem I still has was that 'show' isn't triggered when a view is first shown if it is the first view shown. Er, so yeah I had to add some extra code for that too like this:
if ($('#my-view').is(':visible')) {
$('#my-view').trigger('show');
}
Lame but it works.

Lazy loading list box, in a panorama page

I wanted to add a lazy loading list box(load content when swipe) in a panorama page in one of my windows phone 7 applications. I could however do it using a pivot page. I referred this link
But this is not working with panorama page. Can anyone please help me?
Okay, you're going to need to do one of two things: use the BCL Async package (basically adds async Tasks and such to WP7) or use a background worker. I highly suggest the BCL Async package, it's easy to get on Nuget.
Now, in your ViewModel (you are using MVVM, yes?) the property that it's bound to, let's call it Items should return an ObservableCollection of the item type you need. Now, here's where the magic happens. In the Getter of that property, return a new collection and use a task to fill it. Something like this:
public ObservableCollection<object> Items
{
get
{
ObservableCollection<object> retCollection = new ObservableCollection<object>();
FillCollection(retCollection);
return retCollection;
}
}
public async void FillCollection(ObservableCollection<object> collectionToFill)
{
Task.Factory.StartNew(() =>
{
foreach(object objectToAdd in collectionImGettingThisDataFrom)
{
// We do this using the Dispatcher to
// be sure to pop back into the UI thread.
Deployment.Current.Dispatcher.BeginInvoke(
() => collectionToFill.Add(objectToAdd));
}
}
}
Because FillCollection is async, the Get method will continue and return the current collection. On another thread, the Task that's created will find the data to add, then push it to the UI thread to add it into the collection. This way, you'll be able to lazy load the data only when you ask for it, without completely blocking your UI thread. If it turns out that it's still making your UI slow, you can add the line:
await TaskEx.Delay(25); // Some time in milliseconds. Too much and it will
// take a long time to load the list,
// too little and it will still bog down your UI.
At the end of the foreach block, but not in the Dispatcher invokation.
Happy coding!
Have you looked at the Telerik Rad Controls yet? They have all types of pull to refresh controls. I used them in a recent app I released called "Rad Libs". You can see the controls here http://www.telerik.com/products/windows-phone.aspx and you can also download an app that demos all of their controls. (Disclaimer: I have no affiliation with telerik. I stand to gain nothing from promoting them here)

Handling Asynchronous operations in Windows Phone7

I am developing a Windows Phone7 application in which I have two App bar buttons both when clicked makes Asynchronous calls to Web and Callbacks will be performed upon the Web response.
Now my problem is, if I click on one button and as the Async operation is going on in the background ans meanwhile if I click on another button both callbacks are executing one after the other, which is not good for obvious reasons. Could any one help me on how to handle this???
First I thought to disable other buttons when 1 Async operation is going. But it doesnt give good feel for user. So what will be the best way to handle this problem??
You can use a Flag variable and check its value within the async call complete method. Based on your requirement you can choose to update or not update the view.
I was looking for the same answer.
I have found the solution, If you initialize an object inside a constructor like this, you will get multiple loops when you call a service function:
public partial class MainPage : PhoneApplicationPage
{
MovieServiceClient mov;
public MainPage()
{
mov = new MovieServiceClient(); //Don't do this.
InitializeComponent();
}
}
Avoid that.

Google Chrome Extension - How can I include a content script more than once?

I've been working on Chrome Extension for a website for the past couple of days. It's coming along really nicely but I've encountered a problem that you might be able to help with.
Here's an outline of what the extension does (this functionality is complete):
A user can enter their username and password into the extensions popup - and verify their user account for the particular website
When a user browses http://twitter.com a content script is dynamically included that manipulates the DOM to include an extra button next to each tweet displayed.
When a user clicks this button they are presented with a dialog box
I've made a lot of progress but here is my problem:
When a user visits Twitter the content script is activated and all tweets on the page get my new button - but if the user then clicks 'More...' and dynamically loads the next 20 tweets... these new additions to the page DOM do not get affected by the content script (because it is already loaded).
I could add an event listener to the 'More...' button so it then triggers the original content script again (and adds the new button) but i would have to predict the length of twitter's ajax request response.
I can't tap into their Ajax request that pulls in more tweets and call my addCurateButton() function once the request is complete.
What do you think is the best solution? (if there is one)
What you want to do is to re-execute your content-script every time the DOM is changed. Luckily there is an event for that. Have a look at the mutation event called DOMNodeInserted.
Rewrite your content script so that it attaches an event listener to the body of the DOM for the DOMNodeInserted event. See the example below:
var isActive = false;
/* Your function that injects your buttons */
var inject = function() {
if (isActive) {
console.log('INFO: Injection already active');
return;
}
try {
isActive = true;
//inject your buttons here
//for the sake of the example I just put an alert here.
alert("Hello. The DOM just changed.");
} catch(e) {
console.error("ERROR: " + e.toString());
} finally {
isActive = false;
}
};
document.body.addEventListener("DOMNodeInserted", inject, false);
The last line will add the event listener. When a page loads the event is triggered quite often so you should define a boolean (e.g. var isActive), that you initialize to false. Whenever the inject function is run check whether isActive == true and then abort the injection to not execute it too often at the same time.
Interacting with Ajax is probably the hardest thing to coax a content script to do, but I think you’re on the right track. There are a couple different approaches I’ve taken to solving this problem. In your case, though, I think a combination of the two approaches (which I’ll explain last) would be best.
Attach event listeners to the DOM to detect relevant changes. This solution is what you’ve suggested and introduces the race condition.
Continuously inspect the DOM for changes from inside a loop (preferably one executed with setInterval). This solution would be effective, but relatively inefficient.
The best-of-both-worlds approach would be to initiate the inspection loop only after the more button is pressed. This solution would both avoid the timing issue and be efficient.
You can attach an event-handler on the button, or link that is used for fetching more results. Then attach a function to it such that whenever the button is clicked, your extension removes all the buttons from DOM and starts over inserting them, or check weather your button exists in that particular class of DOM element or not and attach a button if it doesn't.

Observe event created through an instance of a Winforms UserControl

In my winforms app, I have a UserControl that contains a DataGridView. I instantiate and load this UserControl when needed into a panel in my Main Form (frmMain). My problem is figuring out how to resond to or listen for events raised in my UC's DataGridView. For example, I want to handle the CellDoubleClick event of the DataGridView in my Main Form rather than through the UC.
Is this possible? I had thought of updating a property when the cell in the grid is double-clicked, and then let my Main form do whatever when that property changes - therefore I thought of using INotifyPropertyChanged. Im not heavily clued up on how to use it in m scenario however, and would deeply appreciate some help in this regard, or if anyone can suggest an alternate solution.
Much thanx!
Your user control must encapsulate some logic, so if you want to handle event of the DataGridView that is in your control the way you've described, you probably missing something in idea of user controls and encapsulation. Technically here two ways to do this:
Make a public property in your user control of type DataGridView.
Make an event wrapper. You will need to create an event in your user control that is raised when DataGridView CellDoubleClick (or any) is rased and in your calling code you will handle this event wrapper.
The second approach is more logical, cos internal logic of your control is incapsulated and you can provide end-user of you component with more logical and meaningful event then CellDoubleClidk or else.
thank u 4 your reply. Sorry for not responding earlier. I did manage to sort this issue out by creating a public event in my UC:
public event DataGridViewCellEventHandler GridRowDoubleClick {
add { dgvTasks.CellDoubleClick += value; }
remove { dgvTasks.CellDoubleClick -= value; }
}
and in my main form, after I instantiate and load the UC
_ucTask.GridRowDoubleClick += new DataGridViewCellEventHandler(TasksGrid_CellDoubleClick);
with the following attached event:
private void TasksGrid_CellDoubleClick( object sender, DataGridViewCellEventArgs e ) {
// do work here!
}
This does work, although I don't know if any of u experts out there foresee a problem with this approach.

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