Dynamically expand ALL lists and records from json - powerquery

Question

I want to expand all lists and records in a json response.
Columns are like e.g. (this is dynamically, it also can be 10 records and 5 lists):
Text, Text, [List], [List], Text, [Record], [Record], String, [Record]
I wrote a function for getting all columns with the specific type
Cn.GetAllColumnsWithType = (table as table, typ as type) as list =>
let
ColumnNames = Table.ColumnNames(table),
ColumnsOfType = List.Select(ColumnNames, (name) =>
List.AllTrue(List.Transform(Table.Column(table, name), (cell) => Type.Is(Value.Type(cell), typ))))
in
ColumnsOfType;
and a function to expand all lists from a table
Cn.ExpandAllListsFromTable = (table as table, columns as list) =>
let
expandedListTable = List.Accumulate(columns, table, (state, columnToExpand) =>
Table.ExpandListColumn(state, columnToExpand))
in
expandedListTable;
all lists are now records and i want to dynamically expand all these records.
I think i need a foreach to iterate through the list (which are only records cause of Cn.GetAllColumnsWithType),
Table.ExpandRecordColumn each element with it's Table.ColumnNames and add it to the table but i don't know how to do it.
Maybe you can help me out cause it's driving me crazy.
Cheers
Edit:
I recently opened a thread but there i wanted to expand a specific one like
#"SelectItems" = Table.SelectColumns(records,{"$items"}),
#"$items1" = #"SelectItems"{0}[#"$items"],
but now i want to do it all dynamically.

Answer 1

Chris Webb wrote a function to do this for Table-type columns:
http://blog.crossjoin.co.uk/2014/05/21/expanding-all-columns-in-a-table-in-power-query/
I've shared a tweaked version of that that I made for Record-type columns:
https://gist.github.com/Mike-Honey/0a252edf66c3c486b69b

Answer 2

You do not need a function for that. Assuming that the previous step in M was named Removed Other Columns, and that the column to expand is named Data, then make regular Expand step and replace its code of #"Expanded Data" with the following code:
#"Expanded Data"
= Table.ExpandTableColumn(
#"Removed Other Columns",
"Data",
List.Union(List.Transform(#"Removed Other Columns"[Data], each Table.ColumnNames(_)))
)
It expands all columns without referencing their names.