From 7db9a6e48b3e50a47e58e851797016217105d749 Mon Sep 17 00:00:00 2001
From: David Anthoff <anthoff@berkeley.edu>
Date: Thu, 23 Nov 2017 17:43:35 -0800
Subject: [PATCH 1/2] Add support for get_columns_copy interface

---
 src/TableTraitsUtils.jl | 47 +++++++++++++++++++++++------------------
 1 file changed, 27 insertions(+), 20 deletions(-)

diff --git a/src/TableTraitsUtils.jl b/src/TableTraitsUtils.jl
index db59651..1459480 100644
--- a/src/TableTraitsUtils.jl
+++ b/src/TableTraitsUtils.jl
@@ -108,38 +108,45 @@ function _default_array_factory(t,rows)
 end
 
 function create_columns_from_iterabletable(source, sel_cols = :all; array_factory::Function=_default_array_factory)
-    iter = getiterator(source)
+    if supports_get_columns_copy(source)
+        data = get_columns_copy(source)
 
-    T = eltype(iter)
-    if !(T<:NamedTuple)
-        error("Can only collect a NamedTuple iterator.")
-    end
+        columns = [data[i] for i in 1:length(data)]
+        column_names = fieldnames(data)
+    else
+        iter = getiterator(source)
 
-    column_types = TableTraits.column_types(iter)
-    column_names = TableTraits.column_names(iter)
+        T = eltype(iter)
+        if !(T<:NamedTuple)
+            error("Can only collect a NamedTuple iterator.")
+        end
 
-    rows = Base.iteratorsize(typeof(iter))==Base.HasLength() ? length(iter) : 0
+        column_types = TableTraits.column_types(iter)
+        column_names = TableTraits.column_names(iter)
 
-    columns = []
-    for (i, t) in enumerate(column_types)
-        if sel_cols == :all || i in sel_cols
-            push!(columns, array_factory(t, rows))
-        else
-            push!(columns, nothing)
+        rows = Base.iteratorsize(typeof(iter))==Base.HasLength() ? length(iter) : 0
+
+        columns = []
+        for (i, t) in enumerate(column_types)
+            if sel_cols == :all || i in sel_cols
+                push!(columns, array_factory(t, rows))
+            else
+                push!(columns, nothing)
+            end
         end
-    end
 
-    if Base.iteratorsize(typeof(iter))==Base.HasLength()
-        _fill_cols_with_length((columns...), iter)
-    else
-        _fill_cols_without_length((columns...), iter)
+        if Base.iteratorsize(typeof(iter))==Base.HasLength()
+            _fill_cols_with_length((columns...), iter)
+        else
+            _fill_cols_without_length((columns...), iter)
+        end
     end
 
     if sel_cols == :all
         return columns, column_names
     else
         return columns[sel_cols], column_names[sel_cols]
-    end
+    end    
 end
 
 end # module

From 77e9b65198713111c537a0e389123cb16396abef Mon Sep 17 00:00:00 2001
From: David Anthoff <anthoff@berkeley.edu>
Date: Mon, 22 Jan 2018 21:31:06 -0800
Subject: [PATCH 2/2] Add array_conversion argument

---
 src/TableTraitsUtils.jl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/TableTraitsUtils.jl b/src/TableTraitsUtils.jl
index 192b25b..17ae866 100644
--- a/src/TableTraitsUtils.jl
+++ b/src/TableTraitsUtils.jl
@@ -110,11 +110,11 @@ function _default_array_factory(t,rows)
     end
 end
 
-function create_columns_from_iterabletable(source, sel_cols = :all; array_factory::Function=_default_array_factory)
-    if supports_get_columns_copy(source)
+function create_columns_from_iterabletable(source, sel_cols = :all; array_factory::Function=_default_array_factory, array_conversion::Union{Function,Void}=nothing)
+    if array_conversion!=nothing && supports_get_columns_copy(source)
         data = get_columns_copy(source)
 
-        columns = [data[i] for i in 1:length(data)]
+        columns = [array_conversion(data[i]) for i in 1:length(data)]
         column_names = fieldnames(data)
     else
         iter = getiterator(source)