Expressions

This section examines the XQuery Expression system properties as well as useful examples

this.responsecount

Number of responses for the given proposition

this.impressioncount

Number of impression for the given proposition. Note - this should be used with care. The impression counted equates to number of times a proposition has been sent to the client , but not necessarily displayed.

$var//request/<input parameter>

TBC

$var//lastresponse/row/<proposition property>

Retrieve the last response details , for example,

$var//lastresponse/row/propid = "ABC"

returns the last response proposition id and returns 'true' if the value equals 'ABC'

$var//lastimpression/row/<proposition property>

Retrieve the last impression details , for example,

$var//lastimpression/row/propid = "ABC"

returns the last impression proposition id details and returns 'true' if the value equals 'ABC'

Expression Example 1

let $doc :=.

let $doc2 :=

if ($doc//request/operation = "response")

then 1

else

(if (this.responsecount = 0)

then 1 else -1 )

let $return_val := $doc2

return $return_val

This translates to

return '1' if this is a response operation

else

return '1' if there are no responses

else

return '-1' (false)

'this.' is a key word which will allow to access a number of special variables:

responsecount - number of responses for the given proposition

impressioncount - number of impression for the given proposition. Note - this should be used with care. The impression counted equates to number of times a proposition has been sent to the client , but not necessarily displayed.

Expression Example 2

let $doc :=.

let $doc2 := if (($doc//request/EventId = "Event1")

and (this.responsecount = 0)

and ($doc//lastresponse/row/propid = "ABC"))

then 1

else -1 return $doc2

This translates to

return '1' if this is "Event1"

and there are no responses

and the last response involved proposition "ABC"

else

return '-1' (false)

Expression Example 3

let $doc :=. let $doc2 := if ($doc//request/operation = "response")

then 1

else if (($doc//request/EventId = "Event2") and (this.responsecount = 0) and ($doc//lastresponse/row/propid = "XYZ"))

then 1

else -1

return $doc2

Journey Qualifier

• A value of '-1' will filter Journey stages.

• A value of 0 will filter propositions

let $doc :=.

(: Response check :)

let $doc2 := if ($doc//request/operation = "response")

then 1

(: Journey check :)

else if (($doc//request/EventId = "EventId1") and (this.responsecount = 0))

then

(: Proposition check :)

if ($doc//lastresponse/row/propid = "ABC") then 1 else 0

else -1

return $doc2

Input Friendly format

let $doc :=. (: Response check :) let $doc2 := if ($doc//request/operation = "response") then 1 (: Journey check :) else if (($doc//request/EventId = "EventId1") and (this.responsecount = 0)) then (: Proposition check :) if ($doc//lastresponse/row/propid = "ABC") then 1 else 0 else -1 return $doc2