View source for API:DoesWindowExist

{{LuaApi|group=Window}}
Returns whether a window with the given name exists.

<pre>
exists = DoesWindowExist(windowName)
</pre>

== Arguments ==
;windowName : <code>string</code> – Name of the window.

== Returns ==
;exists : <code>boolean</code> – <code>true</code> if the window exists and is not waiting to be destroyed.

== Details ==
* A window that has been passed to <code>DestroyWindow</code> is removed later, not at once. Until then it can still be found by name, but <code>DoesWindowExist</code> already returns <code>false</code> for it.
* This is the usual way to avoid the ''Window %s does not exist'' errors of the other window functions.
* Exactly one argument must be passed. With a missing or non-string argument the function raises the generic ''Invalid Parameters'' message and returns nothing.

== Errors ==
None besides the generic ''Invalid Parameters'' message.

== Example ==
From <code>default/easystem_eventtext/source/system_eventtext.lua</code>:
<pre>
if( EA_System_EventText.loading or ( DoesWindowExist( "LoadingWindow" ) and WindowGetShowing( "LoadingWindow" ) ) )
</pre>

== See also ==
* [[API:WindowGetShowing|WindowGetShowing]]
* [[API:WindowSetShowing|WindowSetShowing]]