Re: [basex-talk] Setting the context item via the native protocol

On 03/14/2012 07:44 PM, Charles Duffy wrote:

Howdy --

Right now, I'm aware of two ways to set the context item via the native protocol:

(1) Insert a "declare context item" header into the document

• Disadvantage: Should only work when XQUERY3 is true
• Disadvantage: Modifies line/column references for errors received
• Disadvantage: Hard to ensure that user-provided XML document will

evaluate to itself in XQuery (security risk)

Bigger disadvantage: ContextItemDecl is allowed only in the second portion of the prolog, so inserting this unambiguously would require parsing the 3rd-party document. Ugh.

(2) Use the "CS" ["Context Set"] command

• Disadvantage: Requires a database to be open (why?)
• Disadvantage: Hard to ensure that user-provided XML document will

evaluate to itself in XQuery (security risk)

I really should have tested before considering this feasible:

CS <root/>

[BASX0007] Query must yield database nodes.