TGIS_FieldRule class

DK11 for Delphi | GisFieldRules.TGIS_FieldRule | Classes | Constructors | Methods | Properties

Class responsible for complete rule based editing of the attribute field.

Available also on: .NET | Java | ActiveX | Python.

// Delphi
type
  TGIS_FieldRule = class
  end;

// C++ Builder
class PASCALIMPLEMENTATION TGIS_FieldRule

1. Create an alias for value 'Tom' of first field :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.ValueAliases.Aliases.Add( TGIS_FieldValueAlias.Create( 'Tommy', 'Tom' ) ) ;
  fld.Rules := r ;
end ;

2. Create a “not null” check for a value after editing :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.ValueChecks.Checks.Add(
    TGIS_FieldValueCheck.Create( TGIS_FieldValueCheckMode.AfterEdit,
                                 TGIS_FieldValueCheckFormula.Required,
                                 '',
                                 'Cannot be null'
                                )
  ) ;
  fld.Rules := r ;
end ;

3. Create a default value for a field :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.Values.DefaultValue := 'unknown' ;
  fld.Rules := r ;
end ;

4. Create a list of available values for a field :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.Values.Mode := TGIS_FieldValuesMode.SelectList ;
  r.Values.Items.Add( 'Ala'  ) ;
  r.Values.Items.Add( 'Tom'  ) ;
  r.Values.Items.Add( 'Boby' ) ;
  fld.Rules := r ;
end ;

5. Create a validator of a field value :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.ValueChecks.Checks.Add(
    TGIS_FieldValueCheck.Create( TGIS_FieldValueCheckMode.AfterEdit,
                                 TGIS_FieldValueCheckFormula.Regex,
                                 '[a-zA-Z0-9_.+-]+@[a-zA-Z0-9-]+\.[a-zA-Z0-9-.]+',
                                 'Invalid email'
                                )
  ) ;
  fld.Rules := r ;
end ;

6. Create a value formatter that can be used in attributes control to display e.g. '10 cm' :

var
  r   : TGIS_FieldRule ;
  fld : TGIS_FieldInfo ;
begin
  fld := layer.FieldInfo(0) ;
  r := TGIS_FieldRule.Create ;
  r.ValueFormat := '%s cm' ;
  fld.Rules := r ;
end ;

7. Save field rules to a file :

  TGIS_FieldRulesOperations.SaveFldx( 'myrules' + GIS_FLDX_EXT, layer ) ;

8. Load field rules from a file :

  TGIS_FieldRulesOperations.ParseFldx( 'myrules' + GIS_FLDX_EXT, layer ) ;

• FieldRules sample