~~Title: OnBeforeFolderChange ~~
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The **OnBeforeFolderChange** event can be implemented by a [[:scripting:script_add-ins|script add-in]] to receive notification before a new folder is read in a tab. Use the **OnAfterFolderChange** event if you want notification //after// a folder has been read.


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$$ (#)**Method Name:**
$$ OnBeforeFolderChange
$$ (#)**Argument Type:**
$$ **[[..:scripting_objects:beforefolderchangedata|BeforeFolderChangeData]]** 
$$ (#)**Return Type:**
$$ //bool// or //string//
$$ (#)**Description:**
$$ The **BeforeFolderChangeData.tab** property identifies the tab, and the **path** property identifies the folder about to be read. The **initial** property indicates if this is the first folder read into this tab - if **True**, it means the tab was previously empty or newly opened.

You can return two different types from this event:
  * //bool//: If you return **True**, the folder read will be blocked and the tab will be unchanged. If you return **False** the read will be allowed to continue (this is the default). 
  * //string//: You can return a //string// (or a **[[..:scripting_objects:path|Path]]** object) to change the folder path to be read. \\
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