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EXTENDING DREAMWEAVER CS4

Menus and menu commands

12 The dialog box remains visible until one of the scripts in the menu commands file calls the window.close()

function.

A simple menu command example

This simple menu command example shows how Undo and Redo menu commands might work. The Undo menu

command reverses the effect of a user’s editing operation, and the Redo item reverses an Undo operation and restores

the effect of the user’s last editing operation.

You implement this example by creating the menu commands, writing the JavaScript code, and placing the command

file in the Menu folder.

Create a menu command

To create a menu called MyMenu that contains the Undo and Redo menu commands, add the following HTML menu

tags. Add the tags after the last closing

</menu> in menus.xml.

<menuitem name="MyUndo" key="Cmd+Z" file="Menus/MyMenu.htm" arguments="'undo'"

id="MyMenu_Edit_Undo" />

<menuitem name="MyRedo" key="Cmd+Y" file="Menus/MyMenu.htm" arguments="'redo'"

id="MyMenu_Edit_Redo" />

</menu>

The key attribute defines keyboard shortcuts that the user can type to load the menu command. The file attribute

specifies the name of the menu command file that Dreamweaver executes when Dreamweaver loads the command.

The value of the

arguments attribute defines the arguments that Dreamweaver passes when it calls the

receiveArguments() function.

The following figure shows these menu commands:

JavaScript code for the menu

When the user selects either Undo or Redo on the MyMenu menu, Dreamweaver calls the MyMenu.htm command

file, which is specified by the

file attribute of the menuitem tag. Create the MyMenu.htm command file in the

Dreamweaver Configuration/Menus folder and add the three menu command API functions,

canAcceptCommand(),

receiveArguments(), and setMenuText(), to implement the logic associated with the Undo and Redo menu items.

The following sections describe these functions.

canAcceptCommand()

Dreamweaver calls the canAcceptCommand() function for each menu item in the MyMenu menu to determine

whether it should be enabled or disabled. In the MyMenu.htm file, the

canAcceptCommand() function checks the

value of

arguments[0] to determine whether Dreamweaver is processing a Redo menu item or an Undo menu item.

If the argument is

"undo", the canAcceptCommand() function calls the enabler function dw.canUndo() and returns

the returned value, which is either

true or false. Likewise, if the argument is "redo", the canAcceptCommand()

function calls the enabler function

dw.canRedo() and returns its value to Dreamweaver. If the canAcceptCommand()

function returns the value

false, Dreamweaver dims the menu item for which it called the function. The following

example shows the code for the

canAcceptCommand() function:

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