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Eric Norman commented on SLING-2803: ------------------------------------ If I recall correctly, sometimes errors occur before the post processor gets a chance to run. So I would think doing validation as a pre processor would catch a larger universe of errors and give the developer a better chance of providing a meaningful error back to the user. If you are doing validation in a post processor, there could have been other exceptions raised before it gets to that point. However, doing a generic validation technique could be complex to do right since the request parameters can be expressed in many different ways. In the sling projects where I have done validation, I have always registered my own servlet/script for the POST method that pre-validates the expected request parameters. If there are any errors, I collect the info and forward back to the original html page to display the form again with the errors reported. If there are no validation errors, I would just forward the request to the default sling post servlet to do the rest of the work. Trying to do validation for the generic post servlet is a more challenging problem since I can imagine situations where a submitted value is valid for a node/resource type but not valid for a specific use case. For example, perhaps in a field in a form is sending a date value that the user picks from a calendar. The validator resource type could validate that the supplied value has the right syntax for a calendar value, but perhaps in some usage of that resource type, the calendar value must be in future. My point is that I wouldn't want to have to make new resource types to modify the validation behavior for different contexts. > Create a Validation module capable of validating POST requests or Resources > --------------------------------------------------------------------------- > > Key: SLING-2803 > URL: https://issues.apache.org/jira/browse/SLING-2803 > Project: Sling > Issue Type: New Feature > Reporter: Radu Cotescu > > Several Sling users have asked in the past [1] about a Validation mechanism > in Sling that's able to validate data coming from the user. However, such a > module is still missing. > This issue is meant to track the work progress on such a module. > Ideally the module should be able to validate both request parameters and > Resources, by obtaining their properties via a ValueMap and provide feedback > in case of a validation error. > [1] - http://sling.markmail.org/search/?q=validation -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira