Problems with QtXQuery in qt 5.12.8

Question

I am trying to read xml tags from a document using QtXQuery. Works out fine besides a '\n'-char that is attached to each query-result. Moreover using the last()-statement on a collection returns the expected number of items in the collection with a trailing repetition + '\n'. Why QXmlQuery seem to add a ` \n` to results? (and how to solve it?) suggest to use a QStringList and only take the first item into account, yet this does not seem to work with my setup as using a QStringList on query.evaluateTo(&qsl) fails to return any results. So: my question is if this is a bug in libqt5xmlPatterns5 or if my implementation is the reason for this behavior? Am I missing some details on how to use QtXmlQuery? So here is the piece of code:

get_tag_value:

static lib_int_err_t get_tag_value(QString *result, QUrl schema_file, QString xml_file_name, QString var_name, QString query_str)
{
    lib_int_err_t ret_code = LIE_OK;
    QFile *xml_f= new QFile(xml_file_name);
    xml_f->open(QIODevice::ReadOnly);
    if(result!=nullptr){
        result->clear();
        QXmlSchema xmlschema;
        // QStringList *results = new QStringList();
        xmlschema.load(schema_file);
        QXmlQuery query(QXmlQuery::XQuery10, xmlschema.namePool());
        query.bindVariable(var_name, xml_f);
        query.setQuery(query_str);
        query.evaluateTo(result);
        // result->append(results->first());
        ret_code = LIE_OK;
    }
    else{
        ret_code = LIE_XML_MALFORMED;
    }
    xml_f->close();
    return ret_code;

}

The input query string:

'declare copy-namespaces no-preserve, inherit; declare variable $" + var_name + " external; doc($" + var_name + ")" + "//procLib/last()" '

The schema used for data description:

 <xs:element name="toolConfig">
     <xs:complexType>
         <xs:sequence>
             <xs:element name="processingLibsSettings">
                 <xs:complexType>
                     <xs:sequence>
                         <xs:element name="interfaceSchemaDef" type="xs:string" minOccurs="1" maxOccurs="1"/>
                         <xs:element name="interfaceSchemaPath" type="xs:string" minOccurs="1" maxOccurs="1"/>
                         <xs:element name="processingLibsInstances">
                             <xs:complexType>
                                 <xs:sequence maxOccurs="unbounded">
                                     <xs:element name="procLib" minOccurs="0">
                                         <xs:complexType>
                                             <xs:sequence>
                                                 <xs:element name="procLibConfigName" type="xs:string"/>
                                                 <xs:element name="procLibConfigPath" type="xs:string"/>
                                                 <xs:element name="procLibName" type="xs:string"/>
                                                 <xs:element name="procLibPath" type="xs:string"/>
                                             </xs:sequence>
                                         </xs:complexType>
                                     </xs:element>
                                 </xs:sequence>
                             </xs:complexType>
                         </xs:element>
                     </xs:sequence>
                 </xs:complexType>
             </xs:element>
             <xs:element name="installDir" type="xs:string"/>
         </xs:sequence>
     </xs:complexType>
 </xs:element>

score 0 · Accepted Answer · answered Apr 03 '21 at 15:15

0

Solved this with a workaround:

results=results.remove('\n');
results=results.split(' ')[0];

not really nice, but it works...

answered Apr 03 '21 at 15:15

cpt-nil

1
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Problems with QtXQuery in qt 5.12.8

1 Answers1