XML : Data filtering

[somnathbanik]

Hi,
I have an xml like below

 <channel>
    <item>
          <type> On </type>
          <title> item1 <</title>
           <imagePath> http://... </imagePath>
     </item>
<item>
          <type> On </type>
          <title> item2 <</title>
           <imagePath> http://... </imagePath>
     </item>
<item>
          <type> Off </type>
          <title> item3 <</title>
           <imagePath> http://... </imagePath>
     </item>
<item>
          <type> Off </type>
          <title> item4 <</title>
           <imagePath> http://... </imagePath>
     </item>
<item>
          <type> On </type>
          <title> item5 <</title>
           <imagePath> http://... </imagePath>
     </item>
</channel>

I am using XmlListModel to parse the XML and display the xml content in a delegate like below

XmlModel {id: feedModel}
    ListView {
        id: list
        width: mainwindow.width ; height: mainwindow.height
        model: feedModel
        delegate: NewsDelegate {}
    }

With this above code I can perfectly display all the items in the listview. Now what I am trying to do is, I just want to display the items that are having On in there <type> tag.
I put a check in the delegate file and can display item that are having On in there <type> tag, with the below code

                Image {
                    id: thumb
                   source: if(type == "On"){imagePath}   // display only one  category item
                    x: 1; y: 1; smooth: true
                }

But when I do this it displays the 1st, 2nd and the 5th items leaving the 3rd and 4th place blank (empty). I mean in the listview the 3rd and 4th place remains empty, and the 5th item doesn't comes after the 2nd item.


Any idea why this is happening or how can I resolve this. please suggest me

[hamishwillee]

I can guess why this happens, but not how to fix it.

According to the documentation the model creates an item for every element matching the XPATH in the "quer"y statement. You haven't declared a query so you're getting all elements - creating an item for each. When you set the source of the image to nothing you still get the item.

I'm not sure of the solution because I don't know enough about XPATH. I'd see if there is any way in XPATH to look at the content of type and then use this to specify the parent items. If not, next best guess would be to try filtering the list to remove any items which don't match your requirement as a post process. Lastly, you might try setting these items to have zero height or to be invisible.

Good luck. Please post your end solution here.

See this bit:

[hamishwillee]

Further to my last response, try the advice in the query element using a query similar to that defined here: http://stackoverflow.com/questions/4...lement-filters

[somnathbanik]

I can guess why this happens, but not how to fix it.

According to the documentation the model creates an item for every element matching the XPATH in the "quer"y statement. You haven't declared a query so you're getting all elements - creating an item for each. When you set the source of the image to nothing you still get the item.

I'm not sure of the solution because I don't know enough about XPATH. I'd see if there is any way in XPATH to look at the content of type and then use this to specify the parent items. If not, next best guess would be to try filtering the list to remove any items which don't match your requirement as a post process. Lastly, you might try setting these items to have zero height or to be invisible.

Good luck. Please post your end solution here.

See this bit:

Thank you for your reply, it clears me a lot. You are right. My query: "/rss/channel/item" creates a model for each <item> tag, and even if I don't display any image it ocupies the blank space. Is there any way I could put a check in the XmlListModel so that it can only reads those item which has the <type> tag On, or its can't happen as because the query reads from item to item.


Even I tried to make the unwanted item to be Invisible, but it invisible all the items along with the one i am looking for.
i use the the visible:
here is the code

 Image {
                    id: thumb
                   source: if(type == "On"){imagePath}   // display only one  category item
                    x: 1; y: 1; smooth: true
                }

could you please help me to put a code how can I invisible the items that are not On, so the I can see only the On items continuously without any blank space.

[somnathbanik]

Further to my last response, try the advice in the query element using a query similar to that defined here: http://stackoverflow.com/questions/4...lement-filters

You are great , this solve this issue. Here is my query query: "/rss/channel/item[type='On']"


Thank you Hamish