Adding controls at run-time in your form? Your controls might not work as expected, if you haven't considered this already

  


Imagine a situation where you need to add controls to a form, on run time. You have a dynamic source, (example, a booking app, where user would keep on adding newer choices, and you need to bring them to your form as checkboxes -- there is no prefixed set of choices beforehand: it would vary), and you need to add controls to your form by looping through your datasource.
A cool way of doing this is to use: Form build controls. For example, for the above situation, you can add FormBuildCheckBoxControl. Or if you need to fill in into a combobox control, you might use FormBuildComboBoxControl. 
 
So what are FormBuild controls actually? For example, the FormBuildComboBoxControl class lets you create, read, update, and delete X++ code and metadata. It behaves as if you are still in designing the UI and can keep on changing the metdata of various controls, while actually you are running the code.
How to add a FormBuild control:
The following code shows that you are adding a formBuildComboBoxControl to a control group:

formBuildComboBoxCtrl = controlProdAttributeGroups.addControl(FormControlType::ComboBox, strrem(ecoResProductTranslation.Name, ' '));

Where controlProdAttributeGroups is actually the parent group, under which the combo box should appear.
You can give a label to it: formBuildComboBoxCtrl.label(ecoResAttributeType.Name);
You can add items to it:
while select TextValue from prodContextValue
                            where prodContextValue.Value  == ecoResProduct.RecId
{
                            i++;

                            formBuildComboBoxCtrl.item(i);
                            formBuildComboBoxCtrl.text(prodContextValue.TextValue);
}

Alright -- up till here, everything looks good.
Now I would like to make the controls be made visible/invisble on certain situation. Now here is the catch: suppose you have written the above code in the init, aftersuper (meaning after all your form controls got initated), then you can easily do this by saying:
FormBuildControl childControl = _parentControl.controlNum(i);
childControl.visible(false);
Where parent control is the group control under which you have added your control, programtically.
But if you want to do this before init, you have to do this by:

            int controlId = _childControl.Id();
            if (controlId)
            {
                FormControl cnt  = element.design().control(controlId);
                if (cnt)
                {
                    cnt.visible(_visible);
                }
            }
This is because 'element.design' gets initated only after init. 
Please note: if you want to say chindControl.visible(false) after super of init, it won't simply work. Why? 
FormBuildControls are like compiled/built-up controls. Once after 'init' they cannot be accessed to make changes to their metadata. Hence they have to typecasted as FormControl and then their metadata could be manipulated. 
                                   

Comments

Post a Comment

Popular posts from this blog

X++ : mistakes which developers commit the most

Image
   The most important thing is to remember where and when to write the code. a. Developers have an inherent habit of writing erratic select statements: select * from custTable where custTable.AccountNum == <SomeValue> Where in essence we need to make use of optimized choice of fields in the select statement. b. Making use of 'continue' keywords: While select custTrans where <someConditions> { if (cusTTrans.CustGroup != mappingTable.CustGroup) { continue; } } 'Continue' statements are precisely a very unhygienic way of designing your code. The above statement could have been easily ornamented by using exists/not exists joins. Using Continue statements would eventually result in a high performance impact. Also select statements should be made punctuated with a 'firstonly' clause -- just not from best practise standpoint, but also from performance considerations. c. Writing nested loops: This is a common mistake that perha
Read more

Make your menu items visible on main menu, conditionally,, using this cool feature of D365FO

Image
  Wassup guys? I am sure you must have encountered this situation where you needed to display your menuItems, on main menu, based on some condition, haven't you? This was only possible by using config keys and flights. Things get a bit tricky,  when suppose you have a requirement like this: you need to make it dynamic, by introducing a toggle switch on a field on a paremeter form.  Suppose on Accounts Receivables Parameters >> You have a field called ' Show US customer '. You have a requirement that says when you turn on this toggle, then only the menuItem ' Input SSN details ', under AR module. This is now highly acheivable by leveraging subscription to 'SysMenuNavigationObjectFactory' class, simply by saying a. Create a new class USMenuItemsVisibilityManager b. Copy the following method, with proper documentation (don't change signature/anything else) [SubscribesTo(classstr(SysMenuNavigationObjectFactory), staticdelegatestr(SysMenuNavigationObjec
Read more

Speed up your execution performance by using SysGlobalCaches

Image
  Ever come across a situation where you needed to  a. Using a multi-threaded batch to import a journal header and lines, from a staging table. The table already contains the Journal Ids which you need to assign to the header and allocate the lines under that header. b. You need to continuously check after each line being imported, if the journal with the Id has been created. If not, it will create the header and create the lines under it;  If yes, it will directly create the lines for the header (Find or create). c. As you could rightly guess, this architecture has an inherent sluggishness associated with it -- each time you keep on checking if the header has been created or not, it does mean a lot of performance effects, as a consequence. Also as you can understand it's a multithreaded code, which means each thread has no direct relation with the other -- which does mean there is no way I can talk between the threads/pass on any information. SysGlobalCaches to the rescue: I perso
Read more