how to differentiate xml tags that belong to layer1 and those that belong layer2 if they use the same tag name?

Question

in my xml file,
i have same tag name used at different place (layer1 and layer2),
how can i differenciate tags named "<tile gid ="int">" from layer1 and layer2 ?
i need to process them differently depending if they belong to layer1 or layer2...
here's a small sample of my parser and my xml file:

// =================
// xml parser sample
// =================
XmlResourceParser xrp = (XmlResourceParser) ctx.getResources().getXml(R.xml.castle);
  while (xrp.getEventType() != XmlResourceParser.END_DOCUMENT) 
  {
    if (xrp.getEventType() == XmlResourceParser.START_TAG) 
    {
      String s = xrp.getName();
      if (s.equals("tile")) 
      {
        int a = xrp.getAttributeIntValue(null, "gid", 0);
        // process a
      }
    }
  }


// ===============
// xml file sample:
// ===============
<layer name="layer1">
  <data>
    <tile gid="1"/>
    <tile gid="2"/>
    ...
  </data>
</layer>
<layer name="layer2">
  <data>
    <tile gid="1"/>
    <tile gid="2"/>
    ...
  </data>
</layer>

Answer 1

Disclaimer: Don't know anything about android, but usually this kind of a situation is a a good fit for XML namespaces

Answer 2

Your parser code will have to remember which sort of layer it's currently in at the time of the START_TAG event for a tile tag.

One way to do this is to create a field String currentLayer; and somewhere in your code have code segments resembling

if (xrp.getEventType() == XmlResourceParser.END_TAG) 
{
  String s = xrp.getName();
  if (s.equals("layer")) 
  {
    currentLayer = null;  // or something ...
  }
}

and

if (xrp.getEventType() == XmlResourceParser.START_TAG) 
{
  String s = xrp.getName();
  if (s.equals("layer")) 
  {
    currentLayer = xrp.getAttributeValue(null, "name", 0);
  }
}

Then in your code dealing with the tile tag, you'll use that field to decide which action to take with something resembling

if (xrp.getEventType() == XmlResourceParser.START_TAG) 
{
  String s = xrp.getName();
  if (s.equals("tile")) 
  {
    int a = xrp.getAttributeIntValue(null, "gid", 0);
    if ("layer1".equals(currentLayer) {
        // process layer1 tile.
    }
    else if ("layer2".equals(currentLayer) {
        // process layer2 tile.
    }
    else {
        // handle occurrence of tile outside layer.
    }
  }
}

This is not necessarily the best approach, especially if it leads to huge nested if-else constructs, but this might get you started.

A better approach might be to have a field for a delegate that handles tiles, set it to an appropriate "tile-processor" object (which you'll have to define as a separate class) during the start event handling for the layer tag and use it in the handling of the tile tag. But that's harder to put in code snippets.