How to change List to attribute (with ListIndexer transformer loop or another way)?

Hi,

I know that
there are a lot of questions in the forum about that but I’m not able to find
how I can use it correctly. So, for extract my attributes from a list I’m using
ListIndexer after the aggregator (10 listIndexer if I have 10 lines aggregated)
to add a prefix to my attribute (index 0 with prefix for example x0_ and so on).
That works but I think that is not a good way to do that (especially if the
data change and I need to add more ListIndexer).

Is-there a
way to do that with loop or another method (a dynamic way to extract the
attributes)

P.s: I
have many attributes, so expose elements will be more complicated.

Thanks

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Try the ListExploder transformer - that gives you a feature for every list member of every element

thanks. ListExploder will give me the same numbers of geometry before doing aggregate. Example : if I have 10 lines in the same position, then I want to have one line with all attributes of the 10 lines (without doing concatenate).

@miladahmad

Your requirement only needs indeed a listexploder, it gives u a _element_index after exploding.You can concatenate on that.

Be careful extracting listelements or exploding lists after aggregating if sorting the list is involved. (at least up to 2016 version something)

If u sort the list, elements can end up on the wrong geomtry. Sorting should be done prior to aggregating.

Best to use part extractor or deaggregator.

Hi @miladahmad, you can rename list elements to attribute names with a common format containing corresponding index using the BulkAttributeRenamer. Also, if you have exposed the list elements in a transformer interface beforehand, the new names will also be exposed.

thanks for all.

@gio : ListExploder give me many geometries which I do not want. ListAttributEexploder give me a strange things. Also, I do not want to use concatenate (if I want to concatenate then I can do it directly with the aggregator). What I need is one line with many fields of all the lines example : index_1_attribute1,

index_2_attribute1, index_3_attribute1, etc.

I thought it should be easier with python or loop (but I'm not good enough to do it)

I will try the solution of @takashi and then I will write again.

thanks a lot for your help. It's works and It's exactly what i need.

ah, you want to merge the attributes of the overlaps to one record (1 line)

problem is dynamicaly exposing the creted attribute.

Bulkattribute renamer does not rename a existing attribute in @takashi 's example. Just adding listelement index to a string.

You would need a attribute exploder to get the actual attribute name.

And there is the problem, you cant use them (attributes) in the replacer.

ah, you want to merge the attributes of the overlaps to one record (1 line)

problem is dynamicaly exposing the creted attribute.

Bulkattribute renamer does not rename a existing attribute in @takashi 's example. Just adding listelement index to a string.

You would need a attribute exploder to get the actual attribute name.

And there is the problem, you cant use them (attributes) in the replacer.

it works. it give me x0_ActualAttribute1, x1_ActualAttribute1, x2_ActualAttribute1, etc. the bulkAttributeRenamer parameter from Takashi is the secret :)

@takashi: