[basex-talk] JSON output in PHP client
I've been playing a bit with BaseX the last couple of days - and very
excited about the product while doing so - but now I am having problems
outputting JSON from a PHP script.
I have this XQuery:
declare option output:method json;
declare option output:json format=jsonml;
json type=object
{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResults
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/testResults
}
/json
In the BaseX GUI this yields:
[json, {type:object},
[testResults,
[testId,
[_id,
Bio-1]],
[grade,
[user_grade,
7]]],
[testResults,
[testId,
[_id,
Bio-2]],
[grade,
[user_grade,
1
Which is what I expected after reading about the JSONML format. (Not too
happy with that format, but that's another story).
Running exactly the same XQuery form within a PHP script however yields
this:
json type=object
testResults
testId
_idBio-1/_id
/testId
grade
user_grade7/user_grade
/grade
/testResults
testResults
testId
_idBio-2/_id
/testId
grade
user_grade1/user_grade
/grade
/testResults
/json
(script is attached; note that the $ signs have been escaped there so
that PHP will not try to evaluate them)
In other words, the result is being output as XML with an enclosing
json root tag, not as JSON.
What is happening here? And how can I have BaseX return JSON from PHP?
Paul Swennenhuis
?php
/*
* This example shows how queries can be executed in an iterative manner.
* Documentation: http://basex.org/api
*
* (C) BaseX Team 2005-11, BSD License
*/
include(BaseXClient.php);
try {
// create session
$session = new Session(localhost, 1984, admin, a33445);
try {
// create query instance
// make sure to escape $ signs!
$input = XQ
declare option output:json format=jsonml;
json type=object
{
for \$user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResult
testId{\$user/test/_id}/testId
grade{\$user/user_info/user_grade}/grade
/testResult
}
/json
XQ;
//print $input;
$query = $session-query($input);
// bind variable
//$query-bind($name, number);
print $query-execute().\n;
// close query instance
$query-close();
} catch (Exception $e) {
// print exception
print $e-getMessage();
}
// close session
$session-close();
} catch (Exception $e) {
// print exception
print $e-getMessage();
}
?
Re: [basex-talk] JSON output in PHP client
Hi Paul,
Which is what I expected after reading about the JSONML format. (Not too
happy with that format, but that's another story).
I agree; JSONML is a quasi-standard we have adopted, which is mainly useful
for converting arbitrary XML to JSON. If you can decide how your XML format
looks like, I would recommend the standard conversion format:
declare option output:method json;
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResults
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/testResults
}/json
Running exactly the same XQuery form within a PHP script however yields
this:
The query results are currently sent to all clients in their standard
format (i.e., ignoring all serialization parameters). That's why you'll
need to convert your JSON within XQuery:
json:serialize(
json type=array objects='_'{
...
}/json
)
If I remember what was the reason for that design decision, I'll give you
an update soon..
Hope this helps,
Christian
Re: [basex-talk] JSON output in PHP client
Hi Christian,
Thanks for the quick answer.
Unfortunately your proposed solution (json:serialize) does not work in
this case; BaseX returns a BXJS0002 error:
JSON serializer: found, _ expected.
The modified query reads:
json:serialize(
json type=array objects='_'{
for \$user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResult
testId{\$user/test/_id}/testId
grade{\$user/user_info/user_grade}/grade
/testResult
}
/json
)
Paul
Hi Paul,
Which is what I expected after reading about the JSONML format. (Not too
happy with that format, but that's another story).
I agree; JSONML is a quasi-standard we have adopted, which is mainly
useful for converting arbitrary XML to JSON. If you can decide how
your XML format looks like, I would recommend the standard conversion
format:
declare option output:method json;
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResults
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/testResults
}/json
Running exactly the same XQuery form within a PHP script however yields
this:
The query results are currently sent to all clients in their standard
format (i.e., ignoring all serialization parameters). That's why
you'll need to convert your JSON within XQuery:
json:serialize(
json type=array objects='_'{
...
}/json
)
If I remember what was the reason for that design decision, I'll give
you an update soon..
Hope this helps,
Christian
Re: [basex-talk] JSON output in PHP client
I should have run your query before sending you an answer. The
following query should work:
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json
)
Which is what I expected after reading about the JSONML format. (Not too
happy with that format, but that's another story).
I agree; JSONML is a quasi-standard we have adopted, which is mainly useful
for converting arbitrary XML to JSON. If you can decide how your XML format
looks like, I would recommend the standard conversion format:
declare option output:method json;
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
testResults
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/testResults
}/json
Running exactly the same XQuery form within a PHP script however yields
this:
The query results are currently sent to all clients in their standard format
(i.e., ignoring all serialization parameters). That's why you'll need to
convert your JSON within XQuery:
json:serialize(
json type=array objects='_'{
...
}/json
)
If I remember what was the reason for that design decision, I'll give you an
update soon..
Hope this helps,
Christian
Re: [basex-talk] JSON output in PHP client
Still no luck:
JSON serializer: testId is typed as string and cannot be nested
I think I am going to move the JSON conversion to within PHP or
Javascript, and keep the XQueries clean and readable.
Paul
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json
)
Re: [basex-talk] JSON output in PHP client
Hi Paul,
no need to despair ;)
The default JSON converter is the direct one (which would require
testId/ to be declared an object), not JsonML. If you you want to use
JsonML you can do so by using
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json,
map { 'format': 'jsonml' }
)
For some more information you can take a look at
https://docs.basex.org/wiki/JSON_Module
Cheers,
Dirk
On 11/07/14 12:13, Paul Swennenhuis wrote:
Still no luck:
JSON serializer: testId is typed as string and cannot be nested
I think I am going to move the JSON conversion to within PHP or
Javascript, and keep the XQueries clean and readable.
Paul
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json
)
--
Dirk Kirsten, BaseX GmbH, http://basex.org
|-- Firmensitz: Blarerstrasse 56, 78462 Konstanz
|-- Registergericht Freiburg, HRB: 708285, Geschäftsführer:
| Dr. Christian Grün, Dr. Alexander Holupirek, Michael Seiferle
`-- Phone: 0049 7531 28 28 676, Fax: 0049 7531 20 05 22
Re: [basex-talk] JSON output in PHP client
Ah, yes, that did the trick. I read about the options but had forgotten
about it.
Thanks.
I will run some performance tests to decide for json:serialize or PHP
internal conversion which might be considerably slower.
Paul
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json,
map { 'format': 'jsonml' }
)
Re: [basex-talk] JSON output in PHP client
Hi Paul, and thanks Dirk.
One last note: If you plan to stick with JsonML, you can serialize
arbitrary XML data, such as..
json:serialize(
xml{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
result
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/result
}/xml,
map { 'format': 'jsonml' }
)
C.
On Fri, Jul 11, 2014 at 12:48 PM, Paul Swennenhuis p...@swennenhuis.nl wrote:
Ah, yes, that did the trick. I read about the options but had forgotten
about it.
Thanks.
I will run some performance tests to decide for json:serialize or PHP
internal conversion which might be considerably slower.
Paul
json:serialize(
json type=array objects='_'{
for $user in
collection(saveresult)//user[_id=1f2cda8f-a18a-44ba-8d17-73626d472306]
return
_
testId{$user/test/_id}/testId
grade{$user/user_info/user_grade}/grade
/_
}/json,
map { 'format': 'jsonml' }
)
