Quick heads-up, in case anybody else runs into this problem.
Background:
I've been working with passing an ExternalQuestion to MechanicalTurk, and have learned (the hard way) that the 'ExternalURL' component, set up as a "xs:anyURI" in the MTurk AWS schema, does not allow ampersands '&' except if escaped via '&'.
That was not at all obvious. The AWS exception gives is:
<CreateHITResponse>
<OperationRequest>
<RequestId>...</RequestId>
</OperationRequest>
<HIT>
<Request>
<IsValid>False</IsValid>
<Errors>
<Error>
<Code>AWS.MechanicalTurk.XMLParseError</Code>
<Message>There was an error parsing the XML question or answer data in your request. Please make sure the data is well-formed and validates against the appropriate schema. (1291006584155 s)</Message>
</Error>
</Errors>
</Request>
</HIT>/
</CreateHITResponse>Solution:
Replace any instance of & in the ExternalQuestion URI (IE, www.yoursite.com/mturk/a.php?foo=true&bar=false) with & (IE, www.yoursite.com/mturk/a.php?foo=true&bar=false).
That'll fix it.
Reference:
ebay developer docs (strangely enough), External Question documentation.
Tags: #technical