IsAppChangedOnServer
- Last UpdatedOct 29, 2026
- 2 minute read
The function IsAppChangedOnServer checks whether the project files available on the server are newer than the files currently on the client.
|
Function |
Group |
Execution |
String Exp. |
Windows |
Windows Embedded |
IoT View |
Thin Clients |
Mobile Access |
|---|---|---|---|---|---|---|---|---|
|
IsAppChangedOnServer |
System Info |
Synchronous |
Yes |
Supported |
Supported |
Not supported |
Supported |
Not supported |
Syntax
IsAppChangedOnServer("optTagUpdateTrigger")
IsAppChangedOnServer ( { "optTagUpdateTrigger" } )
optTagUpdateTrigger
The name of a project tag that will server as a trigger. When the value of the specified tag changes, the function is executed. Unlike most other functions, once this function is called, it is kept in memory until the project is stopped.
To execute the function at regular intervals, use one of the system tags like Day or Month.
This parameter is optional; if no value is specified, the function is executed immediately and not kept in memory.
Note: If this parameter is enclosed in quotes, the string literal will be used. Otherwise, the value of the tag/expression will be used.
Returned value
This function returns one of the following possible values:
|
Value |
Description |
|---|---|
|
0 |
FALSE (that is, the project files on the server have not changed) |
|
1 |
TRUE (that is, the project files on the server have changed) |
If this function returns TRUE, you can use the function ReloadAppFromServer to update the client.
Notes
For this function, the server is the computer or device that hosts the downloadable project files (for example, screens) for your thin clients. It might be different from the project runtime server (also known as the data server), depending on how you deploy your project. For more information, see Thin Clients (including Mobile Access).
If the Enforce Web functionality equivalence in local project screens option is selected in the project settings, this function cannot be called in VBScript Global Procedures, VBScript scripts (script groups), or other background tasks. This is because the function behaves differently depending on whether you view project screens locally (that is, on the same computer that hosts the project runtime) or remotely. For more information, see Preferences tab.
Examples
Immediately check whether the project files have changed:
IsAppChangedOnServer()
When the value of the tag CheckVersion changes, check whether the project files have changed:
IsAppChangedOnServer("CheckVersion")