Add ability to override the encoding (#29)

* Add ability to override the encoding * Fix option handling for multiple options. * Add example for `generate/2`
joshnuss · Nov 14, 2018 · 88f1c7f · 88f1c7f
1 parent 3a400fd
commit 88f1c7f
Show file tree

Hide file tree

Showing 3 changed files with 46 additions and 2 deletions.
diff --git a/README.md b/README.md
@@ -125,6 +125,27 @@ Outputs
 <html>Hello, world!</html>
 ```
 
+### Encoding
+
+While the output is always UTF-8 and has to be converted in another place, you can override the encoding statement in the xml declaration
+with the `encoding` option:
+
+```elixir
+import XmlBuilder
+
+[XmlBuilder.element(:oldschool, [])]
+|> XmlBuilder.document()
+|> XmlBuilder.generate(encoding: "ISO-8859-1")
+|> :unicode.characters_to_binary(:unicode, :latin1)
+```
+
+Outputs
+
+```xml
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<oldschool/>
+```
+
 ### Formatting
 
 With indentation: `XmlBuilder.generate(doc, format: :indent)`

diff --git a/lib/xml_builder.ex b/lib/xml_builder.ex
@@ -210,12 +210,17 @@ defmodule XmlBuilder do
 
       iex> XmlBuilder.generate({:name, nil, [{:first, nil, "Steve"}]})
       "<name>\\n  <first>Steve</first>\\n</name>"
+
+      iex> XmlBuilder.generate(:xml_decl, encoding: "ISO-8859-1")
+      ~s|<?xml version="1.0" encoding="ISO-8859-1"?>|
   """
   def generate(any, options \\ []),
     do: format(any, 0, options) |> IO.chardata_to_string
 
-  defp format(:xml_decl, 0, _options),
-    do: ~s|<?xml version="1.0" encoding="UTF-8"?>|
+  defp format(:xml_decl, 0, options) do
+    encoding = Keyword.get(options, :encoding, "UTF-8")
+    ~s|<?xml version="1.0" encoding="#{encoding}"?>|
+  end
 
   defp format({:doctype, {:system, name, system}}, 0, _options),
     do: ['<!DOCTYPE ', to_string(name), ' SYSTEM "', to_string(system), '">']

diff --git a/test/xml_builder_test.exs b/test/xml_builder_test.exs
@@ -61,6 +61,24 @@ defmodule XmlBuilderTest do
       expectation = "<level1>\n\t<level2>test_value</level2>\n</level1>"
       assert XmlBuilder.generate(input(), whitespace: "\t") == expectation
     end
+
+    test "encoding defaults to UTF-8" do
+      expectation = ~s|<?xml version="1.0" encoding="UTF-8"?>|
+      assert XmlBuilder.generate(:xml_decl) == expectation
+    end
+
+    test "encoding option is used" do
+      expectation = ~s|<?xml version="1.0" encoding="ISO-8859-1"?>|
+      assert XmlBuilder.generate(:xml_decl, encoding: "ISO-8859-1") == expectation
+    end
+
+    test "encoding option works with other options" do
+      xml = [XmlBuilder.element(:oldschool, [])]
+      |> XmlBuilder.document()
+      |> XmlBuilder.generate(format: :indent, encoding: "ISO-8859-1")
+      expectation = ~s|<?xml version="1.0" encoding="ISO-8859-1"?>\n<oldschool/>|
+      assert xml == expectation
+    end
   end
 
   test "element with content" do