Adobe 38043740 Developing Applications - Page 834

DEVELOPING COLDFUSION 9 APPLICATIONS 829 Requesting and Presenting Information To update or delete data dynamically, do the following: • Specify selectmode="edit" in the cfgrid tag. This lets the user edit the grid. • Specify an onChange attribute in the cfgrid tag. The attribute must use a bind expression to specify a CFC method, JavaScript function, or URL of a page that updates the data source. The bind expression has the same format as the bind expression described in "Dynamically filling form data" on page 825; however, it must take the following bind parameters that the grid automatically passes. These parameters send information about the grid and its state to the onChange function. Parameter name cfgridaction cfgridrow cfgridchanged Description The action performed on the grid. 'U' for update, or 'D' for delete. A structure or JavaScript Object whose keys are the column names and values are the original values of the updated or deleted row. A structure or JavaScript Object with a single entry, whose key is the name of the column with the changed value, and whose value is the new value of the field. If the grid action is delete, this structure exists but is empty. When you update data dynamically, you can also use the onError attribute to specify the name of a JavaScript function to handle any errors that result in a CFC or URL returning an HTTP error status. The method must take two parameters: the HTTP error code and a text message that describes the error. The following example shows an onError handler function: function errorhandler(id,message) { alert("Error while updating \n Error code: "+id+" \nMessage: "+message);} The following example displays the members of a department and lets users edit the data in the fields. When the focus leaves the edited field an onChange event triggers and the form calls the editData CFC function to update the data source. Last updated 1/20/2012