QtXML : read all the nodes of a xml file

Hi,

I have a simple XML document, to test QtXML:

Code:

---

<?xml version = "1.0" encoding="UTF-8" standalone="yes" ?>
<player>
	<name>John</name>
	<informations>
		<date format="JJ/MM/AAAA">31/08/2016</date>
		<points>100</points>
	</informations>
 
	<name>Jack</name>
	<informations>
		<date format="JJ/MM/AAAA">31/08/2016</date>
		<points>100</points>
	</informations>
</player>

---

When I try to read the XML nodes, I can't leave the first child : <name>John

Below is the code :

Code:

---

if (m_xmlFile->open(QIODevice::ReadOnly)) {
   if (!m_domDoc->setContent(m_xmlFile)) {
QDomElement dom_elt = m_domDoc->documentElement();
    QDomNode noeud = dom_elt.firstChild();
//    QDomNode n1 = dom_elt.parentNode();
    QDomElement elt = noeud.toElement();
    QString strElt;
    if (!elt.isNull())
        strElt = elt.tagName();
    else
        strElt="ERROR";
    QMessageBox::information(this, "", strElt);
 
    while (!noeud.isNull()) {
        QMessageBox::information(this, "while", "...");
        QDomElement noeud_element = noeud.toElement();
        if(!noeud_element.isNull()) {
            QMessageBox::information(this, "nom de la balise XML","noeud:"+noeud_element.tagName()
                                     +";texte:"+noeud_element.text());
        }
        noeud.nextSibling();
    }
}
}

---

the message information is always :
noeud: name;texte:john
infinite loop

Why the code doesn't go further ? What I have to add ?
thank you

QDomNode::nextSibling() is a const method, it can't change the "noeud" object.
It returns the "next sibling".

If you don't need the DOM tree for document manipulation, you could alternatively look at QxmlStreamReader.

Cheers,
_

Change line 21 to:

Code:

---

noeud = noeud.nextSibling();

---

A comment about your XML: What you have proposed is not a very useful structure for representing player information. All of the elements are at the same level. There is no real way to tell which "<informations>" element belongs to which player except for the way you have (probably) hand-coded the XML example. If a program wrote this same data, it might do it in a completely different order - all of the <name> elements first, followed by all of the <informations> elements - or maybe in some completely different order. It all depends on the particular DOM implementation. For example, some DOM implementations, like xerces-c, put the attributes in alphabetical order. Qt's DOM implementation doesn't. If you write code that depends on elements being in a certain order, you might end up with problems in a future Qt release.

Your player information is really hierarchical, not flat. Your game has a set of players; each player has a name and score information. So a better way to represent this in XML is to make the document element <players> and add <player> elements for each person:

Code:

---

<?xml version = "1.0" encoding="UTF-8" standalone="yes" ?>
<players>
	<player>
		<name>John</name>
		<informations>
			<date format="JJ/MM/AAAA">31/08/2016</date>
			<points>100</points>
		</informations>
	</player>
	<player>	
		<name>Jack</name>
		<informations>
			<date format="JJ/MM/AAAA">31/08/2016</date>
			<points>100</points>
		</informations>
	</player>
</players>

---

Thank you guys for your reply.
I understood what you wrote d_stranz, and i agree.
The XML structure you proposed helped me, thank you very much !