Adobe 38043740 Developing Applications - Page 739

DEVELOPING COLDFUSION 9 APPLICATIONS 734 Requesting and Presenting Information Reviewing the code The following table describes the highlighted code and its function: Code Description Creates a grid named employee_grid and populate it with the results of the query empdata. If you specify a cfgrid tag with a query attribute defined and no corresponding cfgridcolumn attributes, the grid contains all the columns in the query. Allows the user to select only one cell; does not allow editing. Other modes are row, column, and edit. Puts the contents of the Emp_ID column in the query results in the first column of the grid. Puts the contents of the LastName column in the query results in the second column of the grid. Puts the contents of the Dept_ID column in the query results in the third column of the grid. Creating an editable grid You can build grids to allow users to edit data within them. Users can edit individual cell data, as well as insert, update, or delete rows. To enable grid editing, you specify selectmode="edit" in the cfgrid tag. You can let users add or delete grid rows by setting the insert or delete attributes in the cfgrid tag to Yes. Setting the insert and delete attribute to Yes causes the cfgrid tag to display Insert and Delete buttons as part of the grid. You can use a grid in two ways to change your ColdFusion data sources: • Create a page to which you pass the cfgrid form variables. In that page, perform cfquery operations to update data source records based on the form values returned by the cfgrid tag. • Pass grid edits to a page that includes the cfgridupdate tag, which automatically extracts the form variable values and passes that data directly to the data source. Using the cfquery tag gives you complete control over interactions with your data source. The cfgridupdate tag provides a much simpler interface for operations that do not require the same level of control. Controlling cell contents You can control the data that a user can enter into a cfgrid cell in the following ways: • By default, a cell is not editable. Use the cfgrid attribute selectmode="edit" to edit cell contents. • Use the cfgridcolumntype attribute to control sorting order, to make the fields check boxes, or to display an image. • Use the cfgridcolumnvalues attribute to specify a drop-down list of values from which the user can choose. You can use the valuesDisplay attribute to provide a list of items to display that differs from the actual values that you enter in the database. You can use the valuesDelimiter attribute to specify the separator between values in the valuesvaluesDisplay lists. • Although the cfgrid tag does not have a validate attribute, it does have an onValidate attribute that lets you specify a JavaScript function to perform validation. For more information on controlling the cell contents, see the attribute descriptions for the cfgridcolumn tag in the CFML Reference. Last updated 1/20/2012