Add escape

Author: belloq

README.md

@@ -38,7 +38,7 @@ Product.to_struct("<ProductItem><ID>2</ID><Name>Product2</Name></ProductItem>")
 ## TODO
 - [ ] default values
 - [ ] value parser callback
-- [ ] escape html characters
+- [x] escape html characters
 - [ ] cdata
 - [ ] prefixes
 - [ ] override tag name of sub-items in has_many

lib/xml_mapper.ex

@@ -33,7 +33,8 @@ defmodule XMLMapper do
         generate({root_tag(), __MODULE__, []}, xml_content, false, 0)
       end
       def generate({name, type, opts}, struct, indent) when is_map(struct) and indent == 0 do
-        generate({name, type, opts}, List.flatten([Map.get(struct, name)]), Code.ensure_loaded?(type), indent + 1)
+        content = XMLMapper.Value.escape(Map.get(struct, name))
+        generate({name, type, opts}, List.flatten([content]), Code.ensure_loaded?(type), indent + 1)
       end
       def generate(_tuple, [nil], is_module, _indent) when is_module == true do
         ""

lib/xml_mapper/value.ex

@@ -0,0 +1,31 @@
+defmodule XMLMapper.Value do
+  def escape(string) when is_binary(string) do
+    string
+    |> escape(string, 0, 1, [])
+    |> IO.iodata_to_binary
+  end
+  def escape(data), do: data
+
+  escapes = [
+    {?<, "&lt;"},
+    {?>, "&gt;"},
+    {?&, "&amp;"},
+    {?", "&quot;"},
+    {?', "&apos;"}
+  ]
+
+  for {char, swap} <- escapes do
+    def escape(<<unquote(char), rest::bits>>, string, start, length, acc) do
+      skipped = binary_part(string, start, length - 1)
+      escape(rest, string, start + length, 1, [acc, skipped | unquote(swap)])
+    end
+  end
+
+  def escape(<<_char, rest::bits>>, string, start, length, acc) do
+    escape(rest, string, start, length + 1, acc)
+  end
+
+  def escape(<<>>, string, start, length, acc) do
+    [acc | binary_part(string, start, length - 1)]
+  end
+end

test/xml_mapper/escape_test.exs

@@ -0,0 +1,9 @@
+defmodule XMLMapper.EscapeTest do
+  use ExUnit.Case, async: true
+
+  test "escape" do
+    assert XMLMapper.Value.escape("Lorem & ipsum") == "Lorem & ipsum"
+    assert XMLMapper.Value.escape("Lorem & <ipsum> 'dolor' \"sit\"") == "Lorem &amp; &lt;ipsum&gt; &apos;dolor&apos; &quot;sit&quot;"
+    assert XMLMapper.Value.escape(42) == 42
+  end
+end

test/xml_mapper/xml_build_test.exs

@@ -15,10 +15,18 @@ defmodule XmlBuildTest do
     assert SimpleTwo.to_xml(%{id: 1, name: "Test"}) == ~s|<?xml version="1.0" encoding="UTF-8"?><SimpleTwo><Id>1</Id><Name>Test</Name></SimpleTwo>|
   end
 
+  test "Simple struct - escape" do
+    assert SimpleTwo.to_xml(%{id: 1, name: "Test & test"}) == ~s|<?xml version="1.0" encoding="UTF-8"?><SimpleTwo><Id>1</Id><Name>Test &amp; test</Name></SimpleTwo>|
+  end
+
   test "Nested struct" do
     assert SimpleThree.to_xml(%{id: 1, name: "Test", sub_element: %{id: 2, name: "Sub"}}) == ~s|<?xml version="1.0" encoding="UTF-8"?><SimpleThree><Id>1</Id><Name>Test</Name><SimpleTwo><Id>2</Id><Name>Sub</Name></SimpleTwo></SimpleThree>|
   end
 
+  test "Nested struct - escape" do
+    assert SimpleThree.to_xml(%{id: 1, name: "Test", sub_element: %{id: 2, name: "Sub & <sub>"}}) == ~s|<?xml version="1.0" encoding="UTF-8"?><SimpleThree><Id>1</Id><Name>Test</Name><SimpleTwo><Id>2</Id><Name>Sub &amp; &lt;sub&gt;</Name></SimpleTwo></SimpleThree>|
+  end
+
   test "Renamed tags struct" do
     assert SimpleFour.to_xml(%{id: 1, name: "Test"}) == ~s|<?xml version="1.0" encoding="UTF-8"?><SIMPLEFour><ID>1</ID><Name>Test</Name></SIMPLEFour>|
   end