iContextualSubject Interface (PRIM_DC.IContextualSubject)
Interface that allows a visual host reusable part to determine its current context
Ancestors - None

Details

The PRIM_DC.IContextualSubject is implemented by reusable parts acting as a Visual Host field visualization.
The OnContextChanged method is executed whenever there is a change to any facet of the hosting Field or Grid Column.

Example

The following example uses the iMonitorSubject and iContextualSubject interfaces to support use as a field visualization, in this case an autocomplete feature for SURNAME.
Function Options(*DIRECT)
Begin_Com Role(*EXTENDS #PRIM_PANL *implements #Prim_dc.iMonitorSubject #Prim_dc.iContextualSubject) Defaultpty(Value) Displayposition(1) Height(19) Layoutmanager(#TableLayout_1) Left(0) Tabposition(1) Tabstop(False) Top(0) Width(418)
Define_Com Class(#Surname.Visualedit) Name(#Surname) Displayposition(1) Height(19) Marginleft(0) Parent(#COM_OWNER) Tabposition(1) Width(418)
Define_Com Class(#PRIM_TBLO) Name(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Row) Name(#Row_1) Displayposition(1) Parent(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Column) Name(#Column_1) Displayposition(1) Parent(#TableLayout_1)
Define_Com Class(#PRIM_TBLO.Item) Name(#Item_1) Column(#Column_1) Manage(#Surname) Parent(#TableLayout_1) Row(#Row_1)

• Default property of the Value to allow data values to beset/retrieved
  Define_Pty Name(Value) Get(*auto #Surname) Set(*auto #Surname)
  Mthroutine Name(OnContextChanged) Options(*redefine)
  
• If being hosted in a field
  If (#Context *Is #prim_evp)
  
• Match the edit to the component field state
  #Surname.ReadOnly := (#Context *As #prim_evp).ReadOnly
  #Surname.ShowError := (#Context *As #prim_evp).ShowError
  Endif
  Endroutine
  Evtroutine Handling(#Surname.Changed)
  Signal Event(ValueChanged)
  Endroutine
  Evtroutine Handling(#Surname.AutoCompleting) Value(#Value)
  
• Find the first record matching the entered value
  Select Fields(#Surname) From_File(pslmst2) With_Key(#Value) Generic(*yes)
  #Value := #Surname
  Leave
  Endselect
  Endroutine
  End_Com

  Methods

  Name	Description
  OnContextChanged	The data class context has changed Context

  See also

  All Component Classes
  Technical Reference