[solved] Getting single elements from XML-File

[Rocken]

I want to extract several single elements from this XML-structure:
@
<?xml version="1.0" ?>
<program>

<meta>
<name>somename</name>
<description>descriptiontext</description>
<date></date>
</meta>

<parameters>
<parameter id = "z">
<description>some useful parameter</description>
<type id="integer">
<default>5</default>
<min>0</min>
<max>10</max>
</type>
</parameter>

<parameter id="fast">
<description>should it be fast?</description>
<type id = "bool">
<default>1</default>
</type>

</parameter>
</parameters>

<code>
important text
</code>
</program>
@

This means, that i want to read "program/meta/name", "programm/meta/description", "program/code".
Each into a separate textbox (QML). Is this possible without creating a XMLlistmodel for each item i want to extract?

[GentooXativa]

The easyest way is using XmlListModel and changing their query for each "section" imho

[Rocken]

I expected that.
Thanks for your reply

[Rocken]

In my application the user can select a file from a folderlistmodel an in the onSourceChanged signal handler I give my XmlListModel the path to the xml-file.
How can I change the query to access the other "sections" of the xml-file like described above?
I think that this is not possible with signals because everything is linked together
Is it better to solve the whole XML thing in C++ and not in QML?

@ Browser{
onSourceChanged: {
model.source = source
}
}

 XmlListModel {
    id: model
    source: ""
    query: "/program/meta"

    XmlRole { name: "name"; query: "name/string()" }
    XmlRole { name: "descr"; query: "description/string()" }
}

ListView {
    delegate: Text { text: name + " :  " + descr }
}

@
I want to add an other ListView or Text component to get the field in "program/code" (from post 1) as well.

[GentooXativa]

Try this:

@
XmlListModel {

    property string currentQuery

    id: model
    source: "your_file_or_url.xml"

    query: ""

    XmlRole { name: "name"; query: "name/string()" }
    XmlRole { name: "descr"; query: "description/string()" }

    // and add all the variables who can be extracted with XmlRole, when they doesnt found just return a undefined data

    onCurrentQueryChanged: {
           model.query = mode.currentQuery
           model.reload();
    }
}

ListView {
    delegate: Text { text: name + " :  " + descr }
}

@

Now use your selector to send the
@
model.currentQuery = "/program/meta"
or
model.currentQuery = "/program/parameters/parameter"
or
model.currentQuery = "/program/code"
@

So with only one model you can extract all the information.

[Rocken]

Thanks for your answer,
but I want to display these querys at one time.
Something like this:
@
model.currentQuery = "/program/meta"
then / and
model.currentQuery = "/program/parameters/parameter"
then/ and
model.currentQuery = "/program/code"
@

..to fill out a form and to display the querys (have only one entry) in text elements
@
Text { text: "Name: " + name }
Text { text: "Description: " + descr }
Text { text: "Code: " + code }
...
@

Maybe this is only possible with the help of some string properties? If I change the query, some text elements would certainly only show undefined data. Maybe Qts DOM / SAX handler can get these data on an easier way.

[GentooXativa]

U made something like this, but using the OfflineStorage database to store the results after collect it.

[Rocken]

Thanks, I will try this.
I hope this is not an overkill. Since I just want to get 4-5 elements from this xml file.
But maybe this ist not as simple as I thought.

[GentooXativa]

This is a example i made long time ago for a personal project:
@

XmlListModel {
id: xmlProductsModel

property bool debug : true

source: "http://fakeaddress.com/rss.xml"
query: "/rss/products/product"

XmlRole { name: "id"; query: "id/string()" }
XmlRole { name: "brand"; query: "brand/string()" }
XmlRole { name: "comment"; query: "comment/string()" }
XmlRole { name: "description"; query: "description/string()" }
XmlRole { name: "price"; query: "precio/string()" }
XmlRole { name: "imageUrl"; query: "imageFile/string()" }
XmlRole { name: "categoryId"; query: "catId/string()" }

/**
 * When the model is loaded, insert it into the database and the sqlite model
 */

onStatusChanged : {
    if (xmlProductsModel.status == XmlListModel.Ready) {
        var db = openDatabaseSync("Database", "1.0", "TestDatabase", 3000000);

        db.transaction( function(tx) {
            tx.executeSql('DELETE FROM "products"');
            for (var i = 0; i < count; i++) {

                if(debug) console.debug("Adding new product: (" + get(i).id + ") " + get(i).description );

                tx.executeSql('INSERT INTO products(id, id_cat_prod, brand, description, price, comment, image)'
                      + 'values(?, ?, ?, ?, ?, ?, ?)', [get(i).id, get(i).categoryId, get(i).brand,
                                                        get(i).description, get(i).price, get(i).comment, get(i).imageUrl ]);
            }
        })
        model.updatedSuccessful()
        xmlProductsModel.destroy();
    }
}

}
@

[Rocken]

This seems to work best for me:
"How to Read and Write in XML Files with Qt/C++":https://sites.google.com/a/embeddedlab.org/community/technical-articles/qt/qt-posts/howtoreadandwriteinxmlfileswithqtc

I only have to write a connection to my GUI written in QML. But this shouldn't be a problem.