Chapter 6 Lesson C Creating Custom Forms

Lesson C Objectives Convert data blocks to control blocks Link data blocks to control blocks Create a form that has multiple canvases Create tab canvases Create stacked canvases

CONVERTING A DATA BLOCK TO A CONTROL BLOCK

Converting a Data Block to a Control Block We can create a control block: Manually and drawing the layout by hand Create a data block using the Data Block Wizard and Layout Wizard, then convert it to a control block.

Converting a Data Block to a Control Block There are two steps required to convert a data block to a control block: 1.Change the data block’s Database Data Block property value to No 2.Change the Required property value of the text item that represents the data block table’s primary key to No

Linking a Data Block to a Control Block It is often advantageous to create a form that contains a mix of data blocks and control blocks Often the blocks are linked with a master-detail relationship

Creating the Data Block When linking a data block to a control block, the Data Block Wizard cannot be used to create the master-detail relationship Instead, the data block should be created without any relationship

Linking the Control Block and the Data Block In order to establish the link between the data and control blocks, the data block’s WHERE Clause property is set. The general syntax for this is: fieldname = :control_block.text_item_name

Refreshing the Data Block Values In order to refresh the values of the data block to match the control block, the following commands are used: GO_BLOCK('ENROLLED_STUDENTS'); EXECUTE_QUERY; The GO_BLOCK built-in navigates to the block, while EXECUTE_QUERY refreshes the data.

CREATING FORMS WITH MULTIPLE CANVASES

Creating Forms with Multiple Canvases A well-designed form does not present too much information to the user at one time Using multiple canvases helps to divide information into smaller pieces There are two options for creating forms with multiple canvases: The single-form approach The multiple-form approach

Creating Forms with Multiple Canvases 1.The Single-form Approach This approach makes it easy to share data between the forms. However, since only one form design file (.fmb) exists, only one programmer can work on the canvases at a time. 2.The multiple-form approach involves the creation of a form design file for each canvas This approach allows multiple developers to work on a project and facilitates the reuse of forms However, it is more difficult to share information among the canvases.

Working with Multiple Canvases and Data Blocks When a form contains multiple canvases, it is necessary to specify the canvas on which a data block will appear When each block item is added, the canvas should also be specified It is common to create multiple data blocks when working with multiple canvases This allows the data items to be grouped in small manageable units It is also needed if there are two items with the same name, since items must have unique names within a data block

Specifying the Block Navigation Order When a form contains multiple canvases, the canvas that appears first is the canvas whose block items appear first under the Data Blocks node in the Object Navigator window Note that the order of the canvases is irrelevant; only the order of the blocks matters

Referencing Different Canvases, Form Blocks, and Block Items Forms Builder always displays the canvas containing the item with the form focus Therefore, the GO-ITEM built-in can be used to display a different canvas by placing the focus on an item in that canvas It is a good idea to always preface the item name with the block name using the format: block_name.item_name If two items have the same name but reside in different blocks, and the GO-ITEM built-in references only the item name, a runtime error will occur

CREATING AND CONFIGURING TAB CANVASES IN FORMS

Creating and Configuring Tab Canvases in Forms A tab canvas displays multiple canvases that the user can navigate between by clicking a labeled tab at the top of the canvas They are convenient for organizing a lot of form items or allowing users to navigate through a series of steps

Creating a Tab Canvas Each tab canvas contains tab pages Steps: Creating the form Creating a new content canvas in the form Creating a tab canvas on the content canvas Configuring the tab pages

Creating Form Items on a Tab Canvas Form items are placed on a tab page just like on any other canvas