Error Handling

Error Handling in Applications

Error handling is critical aspect of developing applications in any programming language. Error handling is a mechanism where applications can notify error conditions to end users. A-Stack is a collection of number of atomic domain languages, the error handling varies based on language the application is using. Error handling in A-Stack can be classified into three broad categories -

• Error handling in NewFacetInstances
• Error handling as part of process code in non-workflow definition language.
• Error handling in Workflow Definition Language

Trapping Errors in NewFacetInstances

A-Stack provides <OnError> event as part of Facet life-cycle which can be used 

Trapping Errors in Queries

A-Stack Error handling mechanism can be used to trap errors 

<Query>
  <SetLocalData key="ErrorHandler">
    <Value>
      <SetResponseData>
        <Key>
          Message.Value.Error
        </Key>
        <Value>
          [:$Error:]
        </Value>
      </SetResponseData>
    </Value>
  </SetLocalData>
  <Find Format="Version">
    <VendorInfo1>
      <vendorId>
        <NE>
        </NE>
      </vendorId>
    </VendorInfo1>
  </Find>
</Query>