XML parser not working

Programming Questions

joshuakoo..

in Programming Questions • 1 year ago

Dear all interested readers,

I've been reading alot of forum posts about XML parsing with 2.0, but I don't seem to get why the next code is not working:

XML xml;

void setup() {
size(200, 200);
xml = new XML(this, "http://robotfunk.com/temp/getall.php?keyword[]=&keyword[]=crisis");
int numSites = xml.getChildCount();
for (int i = 0; i < numSites; i++) {
    XML kid = xml.getChild(i);
    String url = kid.getString("artikel");
    String site = kid.getContent();
    println(url + " : " + site);
}
}

What am I doing wrong? I am using a right link, but I get a NPE at:

String url = kid.getString("artikel");

-

Hope that someone knows how to help.

Kind regards,

Joshua

Replies(6)

calsign

Re: XML parser not working

1 year ago

There is probably the case where the element "artikel" doesn't exist...
Surrounding it with a try / catch() statement works as far as I can tell (strangely, a null test doesn't):

try {
XML kid = xml.getChild(i);
String url = kid.getString("artikel");
String site = kid.getContent();
println(url + " : " + site);
} catch(NullPointerException e) {}

joshuakoo..

I don't get it. I worked with SimpleML, and it worked. I got only the part <Artikel>, and not all the rest.

http://robotfunk.com/temp/getall.php?keyword[]=&keyword[]=crisis gives an XML output. You can check it with your browser when you check the source.

joshuakoo..

Re: XML parser not working

1 year ago

@Philo: Your comment has disapeared. Maybe I clicked the delete button. Not sure.

Can you explain me how to solve this problem? I understand that I have to filter the "result" again, but how should I do this? Hope you can help me a bit.

Kind regards,

Joshua

PhiLho

Re: XML parser not working

1 year ago

Sorry, I deleted my answer, because I discovered it was totally wrong...

It was about v.1.5.1's XMLElement, but you use v.2.0a's XML.
It was an opportunity to finally download and try this version, now it is judged mature enough to be shown in the official download page!
I prefer to see the source code, so I did an svn update, but since the repository mixes source code of Processing, of the site itself and of books (I would have preferred separate repositories for all this...), it took forever to download all this (SVN isn't particularly fast!).
I am looking right now into this new XML class, much better since it now uses the standard Java way of handling XML.
As I wrote, it is a good opportunity to update my knowledge of Processing.

I see already that getString() isn't the correct method to use, as it is for getting the value of an attribute.

PhiLho

Re: XML parser not working

1 year ago

OK, the new library is nice because it allows to specify a path to get a given node, avoiding to make manual digging in the XML hierarchy.
So the final code is very simple:

XML xml;
void setup()
{
size(200, 200);
xml = new XML(this, "http://robotfunk.com/temp/getall.php?keyword[]=&keyword[]=crisis");
// println(xml);
XML[] urls = xml.getChildren("result/url");
// println(urls);
XML[] artikels = xml.getChildren("result/artikel");
// println(artikels);
for (int i = 0; i < urls.length; i++)
{
// Assumes we have an URL per article!
println("URL: " + urls[i].getContent() + "\nArtikel: " + artikels[i].getContent());
}
println("Done");
exit();
}

joshuakoo..

Re: XML parser not working

1 year ago

Thank you so much! I understand now what was missing. Will never forget this. Thank you once again.

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