Xiaotingia - Facts and Figures

Xiaotingia - Facts and Figures Name: Xiaotingia; pronounced zhow-TIN-gee-ah Habitat: Woodlands of Asia Historical Period: Late Jurassic (155 million years ago) Size and Weight: About two feet long and five pounds Diet: Insects Distinguishing Characteristics: Small size; long tail; primitive feathers About Xiaotingia In order to understand the importance of Xiaotingia, you need a short lesson about a much more famous animal, Archaeopteryx. When the exquisitely preserved fossils of Archaeopteryx were discovered in Germanys Solnhofen fossil beds in the mid-19th century, naturalists identified this flying, feathered creature as the first true bird, the key missing link in avian evolution. Thats the image that has persisted ever since in the popular imagination, even though better-informed paleontologists now know that Archaeopteryx possessed a weird mix of bird-like and dinosaur-like characteristics, and probably should have been classified as a feathered dinosaur (rather than a primitive bird) all along. So what does all of this have to do with Xiaotingia? Well, this very Archaeopteryx-like critter, discovered in Chinas Liaoning fossil beds, predated its more prominent cousin by five million years, living about 155 rather than 150 million years ago. More important, the research team that examined Xiaotingia identified it right off the bat as a small maniraptoran theropod that shared important features in common with raptor dinosaurs like Microraptor and Velociraptor, rather than a prehistoric birdthe implication being that if Xiaotingia wasnt a true bird, then neither was Archaeopteryx, which was only recently descended from it. This has caused a large amount of consternation in the Archaeopteryx was a bird camp, but hasnt impressed those more dubious paleontologists who doubted Archaeopteryxs credentials in the first place!

How to Display and Edit MEMO Fields in Delphis TDBGrid

How to Display and Edit MEMO Fields in Delphis TDBGrid   If you are developing database applications with tables containing MEMO fields, youll notice that, by default, the TDBGrid component does not show the contents of a MEMO field inside a DBGrid cell. This article provides an idea of how to solve this TMemoFields issue (with a few more tricks)... TMemoField Memo fields are used to represent lengthy text or combinations of text and numbers. When building database applications using Delphi, the TMemoField object is used to represent a memo field in a dataset. TMemoField encapsulates the fundamental behavior common to fields that contain text data or arbitrary length. In most databases, the size of the Memo field is limited by the size of the database. While you can display the contents of a MEMO field in a TDBMemo component, by design the TDBGrid will only display (Memo) for the contents of such fields. In order to actually display some text (from the MEMO field) in the appropriate DBGrid cell, youll only need to add a simple line of code ... For the purpose of the next discussion, lets say you have a database table named TestTable with at least one MEMO field named Data. OnGetText To show the contents of a MEMO field in the DBGrid, you need to attach a simple line of code in the fields  OnGetText  event. The easiest way to create the OnGetText event handler is to use the Fields editor at design time to create a persistent field component for the memo field: Connect your TDataset descendant component (TTable, TQuery, TADOTable, TADOQuery ....) to the TestTable database table.Double click the dataset component to open the Fields editorAdd the MEMO field to the list of persistent fieldsSelect the MEMO field in the Fields editorActivate the Events tab in the Object InspectorDouble click the OnGetText event to create the event handler Add the next line of code (italicized below): procedure TForm1.DBTableDataGetText( Sender: TField; var Text: String; DisplayText: Boolean); begin Text : Copy(DBTableData.AsString, 1, 50); Note: the dataset object is called DBTable, the MEMO field is called DATA, and therefore, by default, the TMemoField connected to the MEMO database field is called DBTableData. By assigning  DBTableData.AsString  to the  Text  parameter of the OnGetText event, we tell Delphi to display ALL the text from the MEMO field in a DBGrid cell.You can also  adapt the DisplayWidth  of the memo field to a more appropriate value. Note: since MEMO fields can be quite BIG, it is a good idea to show only a part of it. In the above code, only the first 50 characters are displayed. Editing on a separate form By default, the TDBGrid does not allow editing of MEMO fields. If you want to enable in place editing, you could add some code to react on a user action that shows a separate window that allows editing using a TMemo component.For the sake of simplicity well open an editing window when ENTER is pressed on a MEMO field in a DBGrid.Lets use the  KeyDown  event of a DBGrid component: procedure TForm1.DBGrid1KeyDown( Sender: TObject; var Key: Word; Shift: TShiftState); begin if Key VK_RETURN then begin if DBGrid1.SelectedField DBTableData then with TMemoEditorForm.Create(nil) do try DBMemoEditor.Text : DBTableData.AsString; ShowModal; DBTable.Edit; DBTableData.AsString : DBMemoEditor.Text; finally Free; end; end; end; Note 1: the TMemoEditorForm is a secondary form containing only one component: DBMemoEditor (TMemo).Note 2: the TMemoEditorForm was removed from the Auto-create forms list in the Project Options dialog window. Lets see what happens in the DBGrid1s KeyDown event handler: When a user presses the ENTER key (we are comparing the Key parameter to the VK_RETURN  virtual key code) [Key VK_RETURN],If the currently selected field in the DBGrid is our MEMO field (DBGrid1.SelectedField DBTableData),We create the TMemoEditorForm [TMemoEditorForm.Create(nil)],Send the value of the MEMO field to the TMemo component [DBMemoEditor.Text : DBTableData.AsString],Display the form modally [ShowModal],When a user finishes with editing and closes the form, we need to put the dataste into the Edit mode [DBTable.Edit],In order to be able to assign the edited value back to our MEMO field [DBTableData.AsString : DBMemoEditor.Text]. Note: if you are looking for more TDBGrid related articles and usage tips, be sure to visit: TDBGrid to the MAX tips collection.