Dynamics properties in components - DynProps

DynVarsEh is declared in a module class TDynVarsEh which implements a dynamic collection of scalar variables. Property of the type declared in the component can store a collection of named dynamic set of variables.

Property type TDynVarsEh is declared with the following components and classes:

• TDBGridEh.DynProps
• TColumnEh.DynProps
• TDBEditEh.DynProps
• TDBDateTimeEditEh.DynProps
• TDBComboBoxEh.DynProps
• TDBNumberEditEh.DynProps
• TDBCheckBoxEh.DynProps

Collection TDynVarsEh generated from class TCollection. In Design-Time can create the elements of the type TDynVarEh with the following properties:

public    
    property AsBoolean: Boolean;
    property AsCurrency: Currency;
    property AsDateTime: TDateTime;
    property AsFloat: Double;
    property AsInteger: LongInt;
    property AsRefObject: TObject;
    property AsString: String;
    property IsNull: Boolean;
published
    property Name: String;
    property Value: Variant;

In Run-Time collection items can be created dynamically by assigning values.

When reading a collection of values DBEditEh1.DynProps ['Var1'].Value, if the item in the collection named 'Var1' is present in the list, it returns the value of the variable. If the element name is not present, it returns the value Unassigned.

When assigning values, the algorithm checks for the item in the collection.

DBEditEh1.DynProps ['Var1'].Value: = 'StrValue1';

If the item named 'Var1' isn’t in the list, a new element is created in the collection and is assigned with the specified value.