Processing 1.0 - Processing Discourse - XMLElement inside multithreaded class?

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Index › Programming Questions & Help › Syntax Questions › XMLElement inside multithreaded class

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XMLElement inside multithreaded class? (Read 407 times)

verwirrt

XMLElement inside multithreaded class?
May 30^th, 2008, 5:05pm

hi again.

i wonder how to get XMLElement to work inside a class.
i had it inside a function and it worked just fine. but since the xml-thingy takes quite a while to load i wanted to multithread it so i can display a loading screen or something thelike.

unfortunately if i put it inside a class it doesn't work anymore. i think it's because in the previous version i had xmlartisttag = new XMLElement(this, getthisartist); and inside a class the "this" won't work...but xmlartisttag = new XMLElement(getthisartist); will start the application but will then "crash" because it can't parse.

inside multithreaded class:
Quote:

class CL_artisttagloader extends Thread{
XMLElement xmlartisttag;

public void run() {
for (int i = 0; i < artistnum; i++)
{

Curstatus = "Searching Tags for "+personalcharts[i].artist;

String getthisartist = convertencoding(personalcharts[i].artist);
getthisartist = "http://ws.audioscrobbler.com/1.0/artist/"+getthisartist+"/toptags.xml";

println(getthisartist);
try {
xmlartisttag = new XMLElement(getthisartist);
} catch (Exception e)
{
println(e);
}

int numartisttag = xmlartisttag.getChildCount();
println(numartisttag);
if (numartisttag >= 1) {
XMLElement artisttag = xmlartisttag.getChild(0);
XMLElement kidartisttag = artisttag.getChild("name");
personalcharts[i].tag = kidartisttag.getContent();
println(personalcharts[i].artist+" "+personalcharts[i].tag);
}
}
sortbytag(artistnum);

}

}

old version that worked fine (but alas without multithreading):
Quote:

void artisttagloader(int numartists){
for (int i = 0; i < numartists; i++)
{

Curstatus = "Searching Tags for "+personalcharts[i].artist;

String getthisartist = convertencoding(personalcharts[i].artist);
getthisartist = "http://ws.audioscrobbler.com/1.0/artist/"+getthisartist+"/toptags.xml";

println(getthisartist);
xmlartisttag = new XMLElement(this, getthisartist);

int numartisttag = xmlartisttag.getChildCount();
if (numartisttag >= 1) {
XMLElement artisttag = xmlartisttag.getChild(0);
XMLElement kidartisttag = artisttag.getChild("name");
personalcharts[i].tag = kidartisttag.getContent();
println(personalcharts[i].artist+" "+personalcharts[i].tag);
}
}
sortbytag(numartists);

}

tried using revision 136 but it somehow doesn't work. copied the revision 136 xml libraries over to my revision 135 but it didn't help.

JohnG

Re: XMLElement inside multithreaded class?
Reply #1 - May 30^th, 2008, 6:13pm

Try something like:
Code:

class CL_artisttagloader extends Thread{
XMLElement xmlartisttag;
PApplet parent;
  CL_artisttagloader(Papplet _parent)
  {
    parent=_parent;
  }
 
  public void run() {
	for (int i = 0; i < artistnum; i++)
	{
    
	    Curstatus = "Searching Tags for "+personalcharts[i].artist;
	    
	    String getthisartist = convertencoding(personalcharts[i].artist);
	    getthisartist = "http://ws.audioscrobbler.com/1.0/artist/"+getthisartist+"/toptags.xml";
	    
	    println(getthisartist);
	    try {
		xmlartisttag = new XMLElement(parent,getthisartist);
	     } catch (Exception e)
		    {
			println(e);  
		    }
 
	    int numartisttag = xmlartisttag.getChildCount();
	    println(numartisttag);
	    if (numartisttag >= 1) {
		  XMLElement artisttag = xmlartisttag.getChild(0);
		  XMLElement kidartisttag = artisttag.getChild("name");
		  personalcharts[i].tag = kidartisttag.getContent();
		  println(personalcharts[i].artist+"  "+personalcharts[i].tag);
		}
	   }
	   sortbytag(artistnum);
    
	  }
 
  
  } 

// and now you need to create your CL_artisttagloader with:

CL_artisttagloader loader;

void setup()
{
  //normal setup...
  CL_artisttagloader(this);
}

verwirrt

Re: XMLElement inside multithreaded class?
Reply #2 - May 30^th, 2008, 7:19pm

thanks for the quick answer. sounds logical too. but i'm unsure as howto integrate the "Thread" into the setup.
Before i initialized (at least tried to Wink

) with:
Quote:

import processing.xml.*;
import java.lang.Thread;
Thread artisttagloaderThread;
void setup(){

Thread artisttagloaderThread = new CL_artistloader();

}

and then the class.

now i tried:
Quote:

import processing.xml.*;
import java.lang.Thread;

CL_artisttagloader loader;
//Thread artisttagloaderThread; <- old version

void setup(){

loader = new CL_artisttagloader(this);
//error message: perhaps you wanted to use the overloaded version "CL_artisttagloader(?? _parent);" instead?

//Thread artisttagloaderThread = new CL_artistloader(); <-- old version

}

//+++++++++++++++++++++++++++++++++++++++++++++++++

class CL_artisttagloader extends Thread{
XMLElement xmlartisttag;

PApplet parent;
CL_artisttagloader(Papplet _parent)
{
parent=_parent;
}

public void run() {
for (int i = 0; i < artistnum; i++)
{

Curstatus = "Searching Tags for "+personalcharts[i].artist;

String getthisartist = convertencoding(personalcharts[i].artist);
getthisartist = "http://ws.audioscrobbler.com/1.0/artist/"+getthisartist+"/toptags.xml";

println(getthisartist);
try {
xmlartisttag = new XMLElement(parent, getthisartist);
} catch (Exception e)
{
println(e);
}

int numartisttag = xmlartisttag.getChildCount();
println(numartisttag);
if (numartisttag >= 1) {
XMLElement artisttag = xmlartisttag.getChild(0);
XMLElement kidartisttag = artisttag.getChild("name");
personalcharts[i].tag = kidartisttag.getContent();
println(personalcharts[i].artist+" "+personalcharts[i].tag);
}
}
sortbytag(artistnum);

}

}

but i get the error message "perhaps you wanted to use the overloaded version "CL_artisttagloader(?? _parent);" instead?"
i tried several things but i'm kinda stupid O_o

eskimoblood Senior Member Offline Posts: 341	Re: XMLElement inside multithreaded class? Reply #3 - May 30^th, 2008, 9:20pm There are a lot of bugs in your thread class. The first one: Papplet _parent should be PApplet _parent. And then a some of the variable will be used without initializing them (personalcharts, artistnum, Curstatus, xmlartisttag).
	Andreas Köberle {eskimoblood}

verwirrt YaBB Newbies Offline Posts: 5	Re: XMLElement inside multithreaded class? Reply #4 - May 30^th, 2008, 9:37pm thanks! sorry, i pasted only the important parts, that's why those variables aren't initialized..my script is way too long to post here

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