Read XML files and select info

MirreCap

Hello everyone,
I am currently developing a project in my master's thesis and need some help. I'm new to Qt Creator 4.8.2 and XML files and so I'm still trying to understand how it works. Right now I have a problem that I can not solve. I'm working with QXmlSimpleReader Class to read this xml file:

<?xml version="1.0" encoding="UTF-8"?>
<hdevelop file_version="1.2" halcon_version="18.11.1.1">
<procedure name="clips_orientation">
<interface>
<oo>
<par name="Clips" base_type="iconic" dimension="0"/>
<par name="Regions" base_type="iconic" dimension="0"/>
<par name="ConnectedRegions" base_type="iconic" dimension="0"/>
<par name="SelectedRegions" base_type="iconic" dimension="0"/>
</oo>
<oc>
<par name="Phi" base_type="ctrl" dimension="0"/>
<par name="Area" base_type="ctrl" dimension="0"/>
<par name="Row" base_type="ctrl" dimension="0"/>
<par name="Column" base_type="ctrl" dimension="0"/>
</oc>
</interface>
<body>
<l>read_image (Clips, clips.png')</l>
<l>draw_circle (WindowHandle, Row1, Column1, Radius)</l>
<l>gen_circle (Circle, Row1, Column1, Radius)</l>
<l>reduce_domain (Clips, Circle, ImageReduced)</l>
<l>threshold (ImageReduced, Regions, 3, 60)</l>
<l>connection (Regions, ConnectedRegions)</l>
<l>select_shape (ConnectedRegions, SelectedRegions, 'area', 'and', 4500, 6300)</l>
<l>orientation_region (SelectedRegions, Phi)</l>
<l>area_center (SelectedRegions, Area, Row, Column)</l>
<l>return ()</l>
</body>
<docu id="clips_orientation">
<parameters>
<parameter id="Area"/>
<parameter id="Clips"/>
<parameter id="Column"/>
<parameter id="ConnectedRegions"/>
<parameter id="Phi"/>
<parameter id="Regions"/>
<parameter id="Row"/>
<parameter id="SelectedRegions"/>
</parameters>
</docu>
</procedure>
</hdevelop>

I need to read the file and return:

All <parameter id=> of the <parameters>-> Area, Clips, Column, ConnectedRegions, Phi, Regions, Row, SelectedRegions
The first word of each line of the <body>-> read_image, draw_circle, gen_circle, reduce_domain, threshold, connection, select_shape, orientation_region and area_center.
From now on thank you very much to who can pay attention to my problem and continuation of good programming.
Best regards, Miguel

mrjj

@MirreCap said in Read XML files and select info:

QXmlSimpleReader

Hi
they show how to use it here
http://www.informit.com/articles/article.aspx?p=1405553&seqNum=3

Basically, you subclass QXmlDefaultHandler and fill out the parsing handlers.

JonB

@MirreCap
For your choice of QXmlSimpleReader, are you wedded to it, I'll just point out https://doc.qt.io/qt-5/qxmlstreamreader.html#details:

QXmlStreamReader is a faster and more convenient replacement for Qt's own SAX parser (see QXmlSimpleReader).

QXmlSimpleReader uses the event/callback-driven approach to parsing, which is "cumbersome" for your own code. If you can, do yourself a favour and at least move to the more convenient QXmlStreamReader.

Using QDomDocument + XQuery/QXmlQuery is even easier, but I have a feeling I have seen this/these are "no longer maintained" and you're supposed to use QXmlStreamReader. Which is a shame/backward step for those of us who like XML.

http://3gfp.com/wp/2014/07/three-ways-to-parse-xml-in-qt/ compares these 3 approaches.