[xsl] to group or not to group

[Maximilian Gärber <max@xxxxxxxxxx>]

Hi,

I need to group articles (order items) based on certain features. I have 
an indicator IsGrouped=true that
tells me which features to look at. Below is a sample that shows what I 
want to accomplish.

I don't know how to start, so any help would be really appreciated.


<Product>

....<FeatureDefinitionList>

........<FeatureDefinition>
............<Id>10519</Id>
............<Key>FK1</Key>
............<IsGrouped>true</IsGrouped>
........</FeatureDefinition>

<!-- further feature definitions ... -->
....</FeatureDefinitionList>

....<ArticleList>

........<Article>
............<Id>100</Id>
............<ArticleFeatureList>
................<ArticleFeature>
....................<FeatureDefinitionId>10519</FeatureDefinitionId>
....................<FeatureValue>AAAA</FeatureValue>
................</ArticleFeature>
............<ArticleFeatureList>
........</Article>

........<Article>
............<Id>101</Id>
............<ArticleFeatureList>
................<ArticleFeature>
....................<FeatureDefinitionId>10519</FeatureDefinitionId>
....................<FeatureValue>AAAA</FeatureValue>
................</ArticleFeature>
............<ArticleFeatureList>
........</Article>

........<Article>
............<Id>102</Id>
............<ArticleFeatureList>
................<ArticleFeature>
....................<FeatureDefinitionId>10519</FeatureDefinitionId>
....................<FeatureValue>BBBB</FeatureValue>
................</ArticleFeature>
............<ArticleFeatureList>
........</Article>

....</ArticleList>




-----------------------
Desired Output:

<Product>

....<ArticleGroup>
........<GroupKey>FK1</GroupKey><GroupValue>AAAA</GroupValue>

............<Article>
................<Id>100</Id>
............</Article>

............<Article>
................<Id>101</Id>
............</Article>

....</ArticleGroup>

....<ArticleGroup>
........<GroupKey>FK1</GroupKey><GroupValue>BBBB</GroupValue>

............<Article>
................<Id>102</Id>
............</Article>

....</ArticleGroup>

</Product>