Event

NSB/App Studio programs run within a special version of a web browser. As a result, they can inherit a lot of the properties of the environment they run in. You can access these properties from within your app.

It is not a complete list: there are additional items in the full HTML documentation. In addition, some browsers may have additional members not shown here.

The event object gets created when an event occurs in your program. Events are usually the result of some interaction on the screen by the user: a click, a mouse move or a field selected. You can assign the name of a function in your program to each of these events. In your function, you can examine the values in the Event object to find out more about what just happened.

You can set an event for an element as follows:

  document.body.onmousedown=bodyMouseDown

When there is a click anywhere in the body, the function bodyMouseDown will be called in your program. You can then examine the event object to find out more information:

  Function bodyMouseDown()
    MsgBox event.type & " at " & event.clientX & "," & event.clientY
  End Function

list of events

onblur	An element loses focus
onchange	The content of a field changes
onclick	Mouse clicks an object
ondblclick	Mouse double-clicks an object
onerror	An error occurs when loading a document or an image
onfocus	An element gets focus
onkeydown
onkeypress	A keyboard key is pressed or held down
onkeyup	A keyboard key is released
onmousedown	A mouse button is pressed
onmousemove	The mouse is moved
onmouseout	The mouse is moved off an element
onmouseover	The mouse is moved over an element
onmouseup	A mouse button is released
onresize	A window or frame is resized
onselect	Text is selected
onunload	}

event properties

altKey	Returns whether or not the "ALT" key was pressed when an event was triggered
button	Returns which mouse button was clicked when an event was triggered
clientX	Returns the horizontal coordinate of the mouse pointer when an event was triggered
clientY	Returns the vertical coordinate of the mouse pointer when an event was triggered
ctrlKey	Returns whether or not the "CTRL" key was pressed when an event was triggered
keyCode	Returns the number of the key that was pressed.
metaKey	Returns whether or not the "meta" key was pressed when an event was triggered
relatedTarget	Returns the element related to the element that triggered the event
screenX	Returns the horizontal coordinate of the mouse pointer when an event was triggered
screenY	Returns the vertical coordinate of the mouse pointer when an event was triggered
shiftKey	Returns whether or not the "SHIFT" key was pressed when an event was triggered
bubbles	Returns a Boolean value that indicates whether or not an event is a bubbling event
cancelable	Returns whether or not an event can have its default action prevented
currentTarget	Returns the element whose event listeners triggered the event
eventPhase	Returns which phase of the event flow is currently being evaluated
target	Returns the element that triggered the event
timeStamp	Returns the time stamp, in milliseconds, from the epoch (system start or event trigger)
type	Returns the name of the event
touches[n].clientX	The x-coordinate of the touch’s location relative to the window’s viewport.
touches[n].clientY	The y-coordinate of the touch’s location relative to the window’s viewport.
touches[n].identifier	The unique identifier for this touch object.
touches[n].pageX	The x-coordinate of the touch’s location in page coordinates.
touches[n].pageY	The y-coordinate of the touch’s location in page coordinates.
touches[n].screenX	The x-coordinate of the touch’s location in screen coordinates.
touches[n].screenY	The y-coordinate of the touch’s location in screen coordinates.
touches[n].target	The target of this touch.

Example

You can set an event for an element as follows:

  document.body.onmousedown=bodyMouseDown

When there is a click anywhere in the body, the function bodyMouseDown will be called in your program. You can then examine the event object to find out more information:

  Function bodyMouseDown()
    MsgBox event.type & " at " & event.clientX & "," & event.clientY
  End Function