Want to put validation(Maximum Characters) on custom metadata

Hi Guys,

I am working on one project where i want to put validation on particular metadata like:

     The maximum character can be 10

     The value of an integer field can be between 1 and 10000

I know we can write one custom component(Filter- validateStandard) and stop it but the error will come after checkin action.

My requirement is I will call checkin service from SOAP or from new ADF user interface or UCM old interface and I want to implement maximum character validation for particular field.

Is there any process put any custom script on Rule?

I have created one Rule and add the metadata and put the below custom script on default section:

<$maxLength=10$>

<$customFieldLength = getValue("#active", fieldName & ":maxLength")$>

But it's not working. Am I doing any wrong? I have got the above hint from Idoc Script ref guide: https://docs.oracle.com/cd/E29542_01/doc.1111/e26694/idoc_script_reference.htm#WCCDV10607