I constructed class system
TTableSpec=class(Tobject)
private
FName : string;
FDescription : string;
FCan_add : Boolean;
FCan_edit : Boolean;
FCan_delete : Boolean;
FFields : array[1..100] of TFieldSpec;
public
property Name: String read FName;
property Description: String read FDescription;
property Can_add : Boolean read FCan_add;
property Can_edit : Boolean read FCan_edit;
property Can_delete : Boolean read FCan_delete;
property Fields : array read FFields;
end;
Thus in TableSpec Fields property shall be the list of fields (I used TFieldSpec array). How to organize the list of fields (using or without using an array) as as a result of compilation I receive an error
[Error] Objects.pas(97): Identifier expected but 'ARRAY' found
[Error] Objects.pas(97): READ or WRITE clause expected, but identifier 'FFields' found
[Error] Objects.pas(98): Type expected but 'END' found
[Hint] Objects.pas(90): Private symbol 'FFields' declared but never used
[Fatal Error] FirstTask.dpr(5): Could not compile used unit 'Objects.pas'
To set the values in an array property, the user needs a control that allows selection of multiple values. When the user submits the form, the selected values are written to array elements. A form can set values in an array property through a grouped set of checkboxes or a multiple-selection list box.
To declare an array of objects in TypeScript, set the type of the variable to {}[] , e.g. const arr: { name: string; age: number }[] = [] . Once the type is set, the array can only contain objects that conform to the specified type, otherwise the type checker throws an error. Copied!
I agree the answer regarding INDEXED properties, given by Andreas, is the solution the poster is looking for.
For completeness, for future visitors, I'd like to point out that a property can have an array type, as long as the type is named. The same applies to records, pointers, and other derived types.
type
tMyColorIndex = ( Red, Blue, Green );
tMyColor = array [ tMyColorIndex ] of byte;
tMyThing = class
private
fColor : tMyColor;
public
property Color : tMyColor read fColor;
end;
Your line
property Fields : array read FFields;
is invalid syntax. It should be
property Fields[Index: Integer]: TFieldSpec read GetField;
where GetField
is a (private) function that takes an integer (the Index
) and returns the corresponding TFieldSpec
, e.g.,
function TTableSpec.GetField(Index: Integer): TFieldSpec;
begin
result := FFields[Index];
end;
See the documentation on array properties.
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