Use of form events in Dynamics 365 for Operations

Form datasource from xFormRun

 [FormEventHandler(formStr(SomeForm), FormEventType::Initialized)]  
 public static void SomeForm_OnInitialized(xFormRun sender, FormEventArgs e)  
 {  
 FormDataSource MyRandomTable_ds = sender.dataSource(formDataSourceStr(SomeForm, MyRandomTableDS));  
 ...  
 }  

Get FormRun from form datasource

 [FormDataSourceEventHandler(formDataSourceStr(MyForm, MyRandomTableDS), FormDataSourceEventType::Written)]  
 public static void MyRandomTableDS_OnWritten(FormDataSource sender, FormDataSourceEventArgs e)  
 {  
 FormRun formRun = sender.formRun() as FormRun;  
 formRun.myCustomMethod();  
 }  

Get FormRun from form control

 [FormControlEventHandler(formControlStr(MyForm, MyButton), FormControlEventType::Clicked)]  
 public static void MyButton_OnClicked(FormControl sender, FormControlEventArgs e)  
 {  
 FormRun formRun = sender.formRun() as FormRun;  
 formRun.myCustomMethod();  
 }  

Access form control from xFormRun

 [FormEventHandler(formStr(SomeForm), FormEventType::Initialized)]  
 public static void SomeForm_OnInitialized(xFormRun sender, FormEventArgs e)  
 {  
 sender.design().controlName(formControlStr(SomeForm, MyControl)).visible(false);  
 }  

Get current record in form control event

 [FormControlEventHandler(formControlStr(SomeForm, SomeButton), FormControlEventType::Clicked)]  
 public static void SomeButton_OnClicked(FormControl sender, FormControlEventArgs e)  
 {  
 SomeTable callerRec = sender.formRun().dataSource(1).cursor();  
 }