value relation widget - drive down lists (filter expression)

[josemvm]

What is the bug?

i had the drive down lists working on both side (qgis desktop form and lizmap form), now they only work on the qgis desktop side.

qgis desktop:

lizmap:
`

i'm using this filter expression "cod_tipo" = current_value ('tipo_abrev') as you can see it in the qgis server logs as below:

09:41:14 INFO Server[375409]: FILTER: "cod_tipo" = current_value ('tipo_abrev')

Steps to reproduce the issue

...

Lizmap version

3.4.6, plugin 3.6.3

QGIS desktop version

3.16.10

QGIS server version

3.16.10

Operating system

Ubuntu 20.04

Browsers

Firefox

Browsers version

93.0

Relevant log output

this is the log when i open the form:
`
09:41:14 INFO Server[375409]: ******************** New request ***************
09:41:14 INFO Server[375409]: Request URL: http://127.0.0.1/cgi-bin/qgis_mapserv.fcgi?service=LIZMAP&request=GetServerSettings&map=%2Fvar%2Fwww%2Fhtml%2Flizmap_web_client%2Flizmap%2Finstall%2Fma%2Ftipo_subtipo.qgs
09:41:14 INFO Server[375409]: Environment:
09:41:14 INFO Server[375409]: ------------------------------------------------
09:41:14 INFO Server[375409]: SERVER_NAME: 127.0.0.1
09:41:14 INFO Server[375409]: REQUEST_URI: /cgi-bin/qgis_mapserv.fcgi?service=LIZMAP&request=GetServerSettings&map=%2Fvar%2Fwww%2Fhtml%2Flizmap%5Fweb%5Fclient%2Flizmap%2Finstall%2Fma%2Ftipo%5Fsubtipo%2Eqgs
09:41:14 INFO Server[375409]: SCRIPT_NAME: /cgi-bin/qgis_mapserv.fcgi
09:41:14 INFO Server[375409]: REMOTE_ADDR: 127.0.0.1
09:41:14 INFO Server[375409]: SERVER_PORT: 80
09:41:14 INFO Server[375409]: QUERY_STRING: service=LIZMAP&request=GetServerSettings&map=%2Fvar%2Fwww%2Fhtml%2Flizmap%5Fweb%5Fclient%2Flizmap%2Finstall%2Fma%2Ftipo%5Fsubtipo%2Eqgs
09:41:14 INFO Server[375409]: REQUEST_METHOD: GET
09:41:14 INFO Server[375409]: HTTP_ACCEPT: */*
09:41:14 INFO Server[375409]: HTTP_USER_AGENT: Lizmap
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.requestReady
09:41:14 INFO Lizmap[375409]: Request headers provided
09:41:14 INFO Lizmap[375409]: No lizmap user groups in request headers
09:41:14 INFO Server[375409]: MAP:/var/www/html/lizmap_web_client/lizmap/install/ma/tipo_subtipo.qgs
09:41:14 INFO Server[375409]: REQUEST:GetServerSettings
09:41:14 INFO Server[375409]: SERVICE:LIZMAP
09:41:14 WARNING [375409]: Service CADASTRE is not registered
09:41:14 INFO Lizmap[375409]: Sending JSON response : {'qgis': {'version': '3.16.10', 'name': 'Hannover', 'version_int': 31610}, 'gdalogr': {'name': 'GDAL 3.0.4, released 2020/01/28', 'version_int': '3000400'}, 'services': ['WMS', 'WFS', 'WCS', 'WMTS', 'ATLAS', 'EXPRESSION', 'LIZMAP'], 'lizmap': {'name': 'Lizmap', 'version': '3.6.3'}}
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.responseComplete
09:41:14 INFO Server[375409]: Request finished in 3 ms
09:41:14 INFO Server[375409]: ******************** New request ***************
09:41:14 INFO Server[375409]: Request URL: http://127.0.0.1/cgi-bin/qgis_mapserv.fcgi?service=WMS&request=GetCapabilitiesAtlas&map=%2Fvar%2Fwww%2Fhtml%2Flizmap_web_client%2Flizmap%2Finstall%2Fma%2Ftipo_subtipo.qgs
09:41:14 INFO Server[375409]: Environment:
09:41:14 INFO Server[375409]: ------------------------------------------------
09:41:14 INFO Server[375409]: SERVER_NAME: 127.0.0.1
09:41:14 INFO Server[375409]: REQUEST_URI: /cgi-bin/qgis_mapserv.fcgi?service=WMS&request=GetCapabilitiesAtlas&map=%2Fvar%2Fwww%2Fhtml%2Flizmap%5Fweb%5Fclient%2Flizmap%2Finstall%2Fma%2Ftipo%5Fsubtipo%2Eqgs
09:41:14 INFO Server[375409]: SCRIPT_NAME: /cgi-bin/qgis_mapserv.fcgi
09:41:14 INFO Server[375409]: REMOTE_ADDR: 127.0.0.1
09:41:14 INFO Server[375409]: SERVER_PORT: 80
09:41:14 INFO Server[375409]: QUERY_STRING: service=WMS&request=GetCapabilitiesAtlas&map=%2Fvar%2Fwww%2Fhtml%2Flizmap%5Fweb%5Fclient%2Flizmap%2Finstall%2Fma%2Ftipo%5Fsubtipo%2Eqgs
09:41:14 INFO Server[375409]: REQUEST_METHOD: GET
09:41:14 INFO Server[375409]: HTTP_ACCEPT: */*
09:41:14 INFO Server[375409]: HTTP_USER_AGENT: Lizmap
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.requestReady
09:41:14 INFO Lizmap[375409]: Request headers provided
09:41:14 INFO Lizmap[375409]: No lizmap user groups in request headers
09:41:14 INFO Server[375409]: MAP:/var/www/html/lizmap_web_client/lizmap/install/ma/tipo_subtipo.qgs
09:41:14 INFO Server[375409]: REQUEST:GetCapabilities
09:41:14 INFO Server[375409]: SERVICE:ATLAS
09:41:14 INFO Server[375409]: VERSION:1.0.0
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.responseComplete
09:41:14 INFO Server[375409]: Request finished in 1 ms
09:41:14 INFO Server[375409]: ******************** New request ***************
09:41:14 INFO Server[375409]: Request URL: http://127.0.0.1/cgi-bin/qgis_mapserv.fcgi?
09:41:14 INFO Server[375409]: Environment:
09:41:14 INFO Server[375409]: ------------------------------------------------
09:41:14 INFO Server[375409]: SERVER_NAME: 127.0.0.1
09:41:14 INFO Server[375409]: REQUEST_URI: /cgi-bin/qgis_mapserv.fcgi
09:41:14 INFO Server[375409]: SCRIPT_NAME: /cgi-bin/qgis_mapserv.fcgi
09:41:14 INFO Server[375409]: REMOTE_ADDR: 127.0.0.1
09:41:14 INFO Server[375409]: SERVER_PORT: 80
09:41:14 INFO Server[375409]: QUERY_STRING:
09:41:14 INFO Server[375409]: CONTENT_TYPE: application/x-www-form-urlencoded
09:41:14 INFO Server[375409]: REQUEST_METHOD: POST
09:41:14 INFO Server[375409]: HTTP_ACCEPT: */*
09:41:14 INFO Server[375409]: HTTP_USER_AGENT: Lizmap
09:41:14 WARNING [375409]: Warning: error parsing post data as XML: at line 1, column 1: error occurred while parsing element. Assuming urlencoded query string sent in the post body.
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.requestReady
09:41:14 INFO Lizmap[375409]: Request headers provided
09:41:14 INFO Lizmap[375409]: No lizmap user groups in request headers
09:41:14 INFO Server[375409]: FIELDS:abrev,subtipo
09:41:14 INFO Server[375409]: FILTER: "cod_tipo"  =  current_value ('tipo_abrev')
09:41:14 INFO Server[375409]: FORM_FEATURE:{"type":"Feature","geometry":null,"properties":[]}
09:41:14 INFO Server[375409]: LAYER:subtipo
09:41:14 INFO Server[375409]: MAP:/var/www/html/lizmap_web_client/lizmap/install/ma/tipo_subtipo.qgs
09:41:14 INFO Server[375409]: REQUEST:getFeatureWithFormScope
09:41:14 INFO Server[375409]: SERVICE:EXPRESSION
09:41:14 INFO Lizmap[375409]: Request headers provided
09:41:14 INFO Lizmap[375409]: No lizmap user groups in request headers
09:41:14 INFO Lizmap[375409]: Request headers provided
09:41:14 INFO Lizmap[375409]: No lizmap user login in request headers
09:41:14 INFO WfsOutputExtension[375409]: WfsOutputExtension.responseComplete
09:41:14 INFO Server[375409]: Request finished in 12 ms

[josemvm]

@nboisteault please check your mailbox

[nboisteault]

Thanks @josemvm . Do you remember when issue first occurred? Lizmap, QGIS Server, lizmap plugin update?

[josemvm]

@nboisteault d don't remember when issue first occurred.
i did the plugin downgrade to 3.6.1 (desktop and server) but problem remains...

thanks

[josemvm]

@nboisteault do you think these issues #2526 and #2540 can be related to this regression (or not)?...

[rldhont]

The attributes of the FORM_FEATURE is empty. So the evaluation of current_value ('tipo_abrev') is Null.

The regression is probably in the way lizmap build FORM_FEATURE based on HTML form.

[rldhont]

@josemvm can you update the expression by removing the space between current_value and ( ?

The expression becomes current_value ('tipo_abrev').

[rldhont]

@nboisteault @mdouchin the regexp to get the field name used in current_value expression method as to be enhanced and tested:

preg_match_all('/\\bcurrent_value\\(\\s*\'([^)]*)\'\\s*\\)/', $exp, $matches);

lizmap-web-client/lizmap/modules/lizmap/classes/qgisExpressionUtils.class.php

Line 62 in 4b2a5e0

preg_match_all('/\\bcurrent_value\\(\\s*\'([^)]*)\'\\s*\\)/', $exp, $matches);

[nboisteault]

@rldhont @mdouchin I take it.

[Gustry]

This kind of regex is indeed very fragile, especially because expression is nearly a free-text area for users, between line breaks, expression comments, spaces etc...
But I understand the need, not sure how we can do.

[josemvm]

@rldhont your suggestion solves the problem!