Take a look into this post where I used the random function for medias, but this can also be used for content nodes. The only thing you have to do is to limit the output via position or so.

Thomas

Thanks Thomas thats great - Only slight hiccup I can see is making sure the same image isn't displayed twice?  As its generating a random number it generate the same number twice, thus showing the same image?  Any ideas on how to get round that?

As I remember is the random function initialized by umbraco and stored in the umbraco cache. So the functions shouldn't return doubled values. But I could be wrong. Take a look into the GetRandom function of umbraco.library:

public static Random GetRandom(int seed)
{
    Random random = (Random) HttpContext.Current.Cache.Get("RandomNumber");
    if (random == null)
    {
        if (seed == 0)
        {
            random = new Random();
        }
        else
        {
            random = new Random(seed);
        }
        HttpContext.Current.Cache.Insert("RandomNumber", random);
    }
    return random;
}

Anyone else with experience for the random function?

Take a look here: http://msdn.microsoft.com/en-us/library/system.random%28VS.80%29.aspx

@thomas: this won't help if he needs more random pics on the same page, using that function it's still possible to get two identical values...

@Lee: i've done similar things (using new Random().Next()), store any number of values in a string (using an xslt extension), which could look like '-15--56--89-' and use this string to compare against the node being processed. Don't have the example at hand, but shout if you need more info.

Cheers,

/Dirk

Hi Dirk - Excellent thanks!  If you have got an example it would be great, I'm slowly trying to get my head round this XSLT stuff :(

Did anyone get anywhere with this? I have the same requirement and I can't find a decent solution.

Hi David

Could this be of any use? http://our.umbraco.org/wiki/reference/xslt/snippets/getting-a-series-of-unique-random-numbers

/Jan

David -

Have a look at http://umbraco.miketaylor.eu/2010/08/26/random-sequence/

This uses an XSLT extension to create an XML fragment containing a series of numbers in a random order.

You can then loop through this sequence in your XSLT like this:

...
<xsl:variable name="allNodes" select="{{ select statement here }}" />
<xsl:for-each select="randSeq:RandomSequence(count($allNodes))">
   <xsl:variable name="thisNum" select="text()" />
   <xsl:variable name="thisNode" select="$allNodes[position() = $thisNum]" />

   <!-- do something with $thisNode -->

</xsl:for-each>

Hope that helps,

Mike

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