I have a question concerning Monotouch.
The situation: I have 2 ViewControllers. The first (let's call it VC-A) looks similar to the contacts edit screen, meaning it has a TableView with multiple Sections each containing Buttons and TextFields. Now when the user clicks one of these Buttons, he will get to the second ViewController (VC-B), which displays a TableView containing data from the database. When the user clicks on any of these rows, VC-B will be closed and i want to display the selected database entry (string) as the title of the Button (in VC-A) which opened VC-B in the first place.
When I did an objective-C project last year, I managed to send data back down the stack by using delegates, but I haven't found a way yet how this works in Monotouch.
I have read several questions here on SO about using the AppDelegate or using singletons, but I'm not sure that this is the right way of returning data from a subview.
You can kind of copy the delegate pattern. Add a C# delegate to your VC-B that takes one parameter, some data structure.
In VC-B's "ViewWillDisappear", call the delegate it it is not null and pass the data on to it.
This way, your calling VC can get acces to the data but you don't need tight coupling between the two controllers. All it has to do, is register a delegate-method in VC-B.
As MonoTouch is .NET4 you can use Func<MyDataStructure> or Action<MyDataStructure> and don't need to use full qualified delegate types.
I have a static singleton class that I use to store "state" type data about my app - current settings and selections that are needed in many different places in the app. That's one way to approach this.
You could also pass VC-B a reference to VC-A when you create VC-B, so that it can explicitly access it's parent view and pass back values that way.
I actually prefer to use TinyMessenger for cross container calls I find this to be very very useful when you don't want to keep references to your heavy viewcontrollers around which could potentially result in memory leaks!
var messageHub = new TinyMessengerHub();
// Publishing a message is as simple as calling the "Publish" method.
messageHub.Publish(new MyMessage());
// We can also publish asyncronously if necessary
messageHub.PublishAsync(new MyMessage());
// And we can get a callback when publishing is completed
messageHub.PublishAsync(new MyMessage(), MyCallback);
// MyCallback is executed on completion
https://github.com/grumpydev/TinyMessenger
Related
I am writing a program that will get user inputs and store data about GUI elements, which user has clicked in desktop applications.
I need data from GUI like: element name, element description, class, element parent, children, etc.
Code is written on C#. As i found out, i can use Xamarin.Mac to call macOs AppKit API from C# (https://learn.microsoft.com/en-us/dotnet/api/appkit.nsapplication?view=xamarin-mac-sdk-14).
Now the question is what do i call to get this data?
Or is there any alternative way to get this data?
First, from the XAML part, make sure the objects have a name defined and that they are public after you can call the variable name in the C# code, and from there put a dot (".") many methods, attributes, and options will appear, for example, you are asking about the children, you could use
var titleBarChildre = AppTitleBar.Children.ToList();
etc.
I‘m working on customization that involves adding extra Sales Person transactions when Cancelling/Correcting an Invoice. As part of the development effort, I have identified that the common method that’s called by both the processes – Cancel Invoice and Correct Invoice, is ReverseDocumentAndApplyToReversalIfNeeded in the Graph PX.Objects.AR.ARInvoiceEntry.
I have the custom code to add new salespersons to the ARInvoiceEntry.salesPerTrans view but when I do after ReverseDocumentAndApplyToReversalIfNeeded runs, I see that my code doesn’t insert the new records to the view and doesn’t give any error. After much troubleshooting, I’ve found out that there’s a line of code in the method ReverseInvoiceProc of ARInvoiceEntry.cs that stops from inserting a new row. Here’s that line of code:
this.RowInserting.AddHandler<ARSalesPerTran>((sender, e) => { e.Cancel = true; });
It’s an anonymous delegate that’s added.
I would like to know how can I get hold of this anonymous handler in my custom code so that I can:
Remove that anonymous handler
Do my custom logic of adding new rows
Add the anonymous delegate back to the RowInsertingEvents list
I tried to look in the Acumatica code repository but couldn’t find anything that would help me remove anonymous delegate. What I can find was the removal of named handlers, like the below example:
APPaymentEntry pe = CreateInstance<APPaymentEntry>();
pe.RowSelecting.RemoveHandler<APPayment>(pe.APPayment_RowSelecting);
So please let me know how can I dynamically remove that anonymous handler from within my custom code. I have reference to the ARInvoiceEntry graph through the Base property of my extension graph. If you can redirect me to a specific page in the Acumatica Code repository, that would work as well.
I do not think you could remove this anonymous method from there in a easy way.
However, one approach you could implement is to override the "ReverseDocumentAndApplyToReversalIfNeeded" method and call base method there.
After this you could create a new instance of the ARinvoiceEntry graph (in that same override after calling base method), select the primary record(header) and then try to make your second insert ( this way to avoid the ReverseInvoiceProc.)
I'm tying to migrate an Epicor V9 system with Progress/ABL code to v10 with C# code. I've got most of it done but I need a way to keep data between a BPMs pre and post processing. The comments in the original ABL code state:
Description : This function stores data from a BPM pre processing action, it does this by using a private-data (storage attribute) on the calling program...
this remains in scope during both the BPM pre and BPM post forward to procedure calls
The Epicor v9 system was set up such that the Quote form calls the BPM pre/post processing in a .p file. The .p file in turned call the code I am trying to migrate in a .i file. It looks to be a simple stack or array of strings.
What would be used in Epicor 10 to persist data between pre/post BPM processing like the .i code did in V9?
You can use CallContext.Properties for this.
In E10.0 the CallContext.Properties was of type Epicor.Utilities.PropertyBag, and items would be accessed as below:
//Add
CallContext.Properties.Add("LineRef", LineRef);
// Get
var LineRef = (string)CallContext.Properties["LineRef"];
// Remove
CallContext.Properties.Remove("LineRef");
E10.1 CallContext.Properties is now of type System.Collections.Concurrent.ConcurentDictionary, which is a .Net built in type and much better documented. However the methods to add and remove entries from it have changes as below:
//Add
bool added = CallContext.Properties.TryAdd("LineRef", LineRef);
// Get
var LineRef = (string)CallContext.Properties["LineRef"]; //Note: Do not use .ToString() this converts instead of unboxing.
// Remove
object dummy;
bool foundAndRemoved = CallContext.Properties.TryRemove("LineRef", out dummy);
To use this your class needs to inherit from ContextBoundBase and implement the only the context bound constructor or you will get 'Ice.ContextBoundBase<Erp.ErpContext>.ContextBoundBase()' is obsolete: 'Use the constructor that takes a data context'
public partial class MyInvokeExternalMethodThing : ContextBoundBase<ErpContext>
{
public MyInvokeExternalMethodThing(ErpContext ctx) : base(ctx)
{
}
In E10.1 you can put any kind of object into this, so if you have an array of strings you don't need to use the old trick of tilde~separated~values.
I don't know about using .i files from E9 but I do know how to persist data between pre and post method directives in E10. Hopefully this helps.
There are a couple of different ways to do this. If when creating the pre-process bpm you chose the "Execute Custom Code" option. You can do it directly in your code using callContextBpmData. Almost all of the field names are similar to that of the user fields that E9 used (i.e. Number01, Chracter01, Date01).
In your code if you are setting text you could simply type:
callContextBpmData.Character01 = "some text";
Alternatively you could set it directly in the bpm designer without any code. In the designer left window pane, scroll all the way to the bottom, you should see something called "Set BPM Data Field". Drag it into the design area. After dragging it into the designer area you should see the option to set a field and its value in the bottom window pane. Select the field, then when you select "value" you are taken to a window similar to baq calculated field designer. You can use static data or use the data in the business object to calculate a value.
I've got a Page, a GridView using an ObjectDataSource with a SelectMethod and a DropDownList. The SelectMethod, among other things, gets a string-array containing several IDs (to filter the Data) - but I also need it as DataSource for the DropDownList.
Alas, I cannot DataBind the DropDownList inside the SelectMethod since it's null.
An Idea would be to bind this string[] to a Session-Variable, but then I'd have to either re-set it upon every Page_Load or remove it from Session on every other page if I want it to update in case something on the Database changed.
What I'm looking for is some kind of variable that is available both in Page_Load and my ObjectDataSources SelectMethod, but that removes itself upon leaving the page (i.e. navigating to any other page on my Web-Application (preferably without having to call a method on EVERY other Page).
I hope you could understand my problem.
Thanks,
Dennis
As I understand the need to fetch the string array arises from the performance hit that a separate roundtrip will cause. To work around this you may create a separate object to feed your object data source. This object will have two methods one for getting the string array and another for getting the data for the grid (i.e. the select method)
You may then put an object like this in your page and fetch the data in it in a lazy manner. If the object makes a call for any of the data it stores the other part in a field. You can then use the ObjectDataSource ObjectCreating event to pass this object on your page to the ObjectDataSource
protected void odsSomething_ObjectCreating(object sender, ObjectDataSourceEventArgs e)
{
e.ObjectInstance = YourInsntanceAlreadyInThePage;
}
This way you will avoid the roundtrip.
Also consider making two web service calls at the same time using the asynchronous client calls so that you can make both calls for the same time. If this is viable depends on the flow of your logic.
What I'm looking for is some kind of variable that is available both in Page_Load and my ObjectDataSource's SelectMethod, but that removes itself upon leaving the page (i.e. navigating to any other page on my Web-Application (preferably without having to call a method on EVERY other Page).
In a similar situation, I've used the Items property of the current HttpContext. It's an IDictionary (non-generic), so can hold arbitrary objects keyed by arbitrary objects, and its lifetime is precisely the duration of the current request, so will go away as soon as the request is ended. To use:
// Where you first get the data
HttpContext.Current.Items["SomeKey"] = new [] { "string1", "string2" };
// Where you want to to use the data
var strings = (string[])HttpContext.Current.Items["SomeKey"];
So I am refactoring a little application as an example to get more practice. The purpose of the application (let's say) is to collect the data from a "sign up new user" form, save it in the database. The only limitation I have is I have to use a special custom Data Access class which communicates directly with the database and returns the data (if applicable) in a DataTable object.
I have a question regarding a little details on a form and how do they fit in into the layer architecture. For example, my form has a drop down list that's fed from the database, but at the same time drop down list doesn't represent an object per SE (unlike a User that is a object, there is a class User that has multiple methods, data members etc). I don't want to have calls to the stored procedure right there in the code behind but I also do not wish to overdo on abstraction.
What would be an elegant way to take care of these little details w/o creating a class abstraction galore.
Hope I am being clear
Funny you should ask that. I went through that issue here.
These other Stack Overflow Questions that I've answered that show other parts (tangentially related):
Getting ListView Data Items from Objects
Working with ListViews
Concatenating Properties in a DropDownList
An option for getting non-object data to the UI is to create one or more lookup classes that are a bucket or "service" for getting odd bits of data for things like drop down lists etc...
Example:
myDDL.DataSource = Lookup.GetAllCountries(); // GetAllCountries is a static method
// set name/value fields etc...
myDDL.DataBind();
Using this methodology, you can still support tier separation. It's not object oriented or elegant, but it is very practical.
I don't know what's best practice, but what I do is I have a utility class that has a method that takes as arguments a DropDownList object and an enum, so I do
FillDropDown( ddlistPhoneType, DropDownTypes.PhoneTypes );
The utility class fills the dropdowns sometimes from the database, other times from XML, and occasionally some hardcoded values. But at least the GUI doesn't have to worry about that.