Question

Hi I need some help in creating a template function (as they are known in c++ if I’m correct). I’m using Delphi XE2, and I’m writing a database application using an MS Access database.

The problem is that there is a lot of functions that I write that does the same thing on different tables. So I thought that I can create template functions and then just use different parameters for the different tables.

For example, there is the Locate function that locates a specific record in a table or query. Now I would like to make a template function of this but I do not know how to do this.

I want to put the function in the public section of my datamodule, so I was thinking in the line of this

function find(tableName: TADOTable, fieldName: String, fieldValue: String):Boolean

Then…

function TDataModule.find(tableName: TADOTable, fieldName: String, fieldValue:String): Boolean;
var SearchOptions : TLocateOptions;
 begin
  SearchOptions := [loCaseInsensitive]; 
  find := DataModule.tableName.Locate('fieldName', fieldValue, SearchOptions);
 end;

But this do not want compile…

It there any way to make some kind of template function where I can pass any table as a parameter or would it be beter to create a class for every single table, with getter and setter functions?

Answer 1

function TDataModule2.LocateData(AADOTable: String; AKeyFields: String; 
  AKeyValues: Variant; Options: TLocateOptions): Boolean;
var
  oComp: TComponent;
begin
  Result := False;
  oComp := FindComponent(AADOTable);
  if (oComp is TADOTable) and (oComp as TADOTable).Active then
    Result := (oComp as TADOTable).Locate(AKeyFields, AKeyValues, Options);
end;