TTMSFNCObjectInspector

Hierarchy

1) The Name column, showing the name of the property

2) The Value column, showing the value / class name of the property

3) An assignable property, shown in red. Can be used to assign an object to a property of a specific class. Typically used for non-visual components, such as TPopupMenu or TTMSFNCBitmapContainer.

4) An expandable property. The object inspector lists the full hierarchy of the object. Assigning an object The TTMSFNCObjectInspector not only supports visual and non-visual components but supports any kind of object. You can easily create your own class and pass this as an object to the object inspector. To do so, create a class inside your unit. For this purpose, we have created a TTestClass with a set of properties of different types.

Assigning an object

The TTMSFNCObjectInspector not only supports visual and non-visual components but supports any kind of object. You can easily create your own class and pass this as an object to the object inspector. To do so, create a class inside your unit. For this purpose, we have created a TTestClass with a set of properties of different types.

type
 TTestProperty = (tpValue1, tpValue2, tpValue3);
 TTestClass = class
 private
 FB: TDate;
 FC: TTestProperty;
 FA: string;
 FObject: TComponent;
 published
 property A: string read FA write FA;
 property B: TDate read FB write FB;
property C: TTestProperty read FC write FC;
 property AssignableObject: TComponent read FObject write FObject;
 end;

The property A is a string property that simply shows an editable field with plain text.

The AssignableObject property is colored in red, which indicates it can be assigned with an instance of an object that is found on the main form, of that specific class type.

The property B is a TDate property that can show an inplace date picker editor.

The property C is a propert of type TTestProperty, which shows a combobox with the possible values.

Reading / Writing properties

With the above sample, the values that are present on the object are all listed inside the object inspector. Sometimes, it might be necessary to hide values from the user, or change the value that is writing to the object property, therefore the object inspector exposes a set of events for reading.

The event OnReadProperty can be used to hide or show the value inside the object inspector. For example, if we want to hide property B, we can write the following code:

procedure TForm1.TMSFNCObjectInspector1ReadProperty(Sender, AObject: TObject;
 APropertyInfo: PPropInfo; APropertyName: string; APropertyType: TTypeKind;
 var ACanRead: Boolean);
begin
 ACanRead := (APropertyName <> 'B');
end;

If you want to display the property, but want to change the value instead, you can use the OnReadPropertyValue event. Below is a sample that shows how to change the default value shown in the object inspector. This can be helpful to predefine a value for a specific property, or manipulate the value that is being read from the property itself.

procedure TForm1.TMSFNCObjectInspector1ReadPropertyValue(Sender,
 AObject: TObject; APropertyInfo: PPropInfo; APropertyName: string;
 APropertyType: TTypeKind; var APropertyValue: string; var ACanRead: Boolean);
begin
 if APropertyName = 'A' then
 APropertyValue := 'Hello World';
end;

Whenever a property value is being changed, the OnWritePropertyValue is being triggered. This event can be used to change the value, or prevent to value from being written to the property. Below is a sample that demonstrates how to change the value being written to the property.

procedure TForm1.TMSFNCObjectInspector1WritePropertyValue(Sender,
 AObject: TObject; APropertyInfo: PPropInfo; APropertyName: string;
 APropertyType: TTypeKind; var APropertyValue: string; var ACanWrite: Boolean);
begin
 if APropertyName = 'A' then
 APropertyValue := 'Changed Value';
end;

Collection / list editor

Whenever a collection / list is detected, the object inspector can show the collection or list inside a popup editor. Below is a sample when we add a TStringList to TTestClass.

type
 TTestProperty = (tpValue1, tpValue2, tpValue3);

 TTestClass = class
 private
 FB: TDate;
 FC: TTestProperty;
 FA: string;
 FObject: TComponent;
 FMyStrings: TStringList;
 public
 constructor Create;
 destructor Destroy; override;
 published
 property A: string read FA write FA;
 property B: TDate read FB write FB;
 property C: TTestProperty read FC write FC;
 property AssignableObject: TComponent read FObject write FObject;
 property MyStrings: TStringList read FMyStrings;
 end;

Click on the MyStrings value column to start the editor. The editor will show the values inside the editor. At the left side a memo is shown which can be used to change the value.

When editing a TCollection, the memo is replaced by a TTMSFNCObjectInspector instance, that allows editing the properties of the TCollectionItem instance, selected from the list at the right side. The changes that are being made to the properties are directly applied to the collection.

Datasource

The TTMSFNCObjectInspector is also capable of showing the fields and fields data from the active record. It also changes the value and posts it directly to the dataset as well as updates automatically when a value in the dataset field changes. Below is a sample that demonstrates this with the biolife.xml file assigned to a TClientDataSet.

Changing a field value will automatically post the value to the dataset. There are equivalent events that can be used to read or write the field value: OnReadDBField and OnReadDBFieldValue and OnWriteDBFieldValue. These events are only triggered when a DataSource is assigned.