Merge pull request #57 from danschultzer/support-css-input

Support css input for inline style parsing

CHANGELOG.md

@@ -1,5 +1,9 @@
 # Changelog
 
+## v0.3.12 (TBA)
+
+* `Premailex.HTMLInlineStyles.process/3` now supports passing in CSS as an argument
+
 ## v0.3.11 (2020-10-08)
 
 * Fixed bug where the inline styles where applied to more than the first match causing in some cases styles to be missing for subsequent parent elements

lib/premailex/html_inline_styles.ex

@@ -9,23 +9,40 @@ defmodule Premailex.HTMLInlineStyles do
   Processes an HTML string adding inline styles.
 
   Options:
-    * `css_selector` - the style tags to be processed for inline styling, defaults to `style,link[rel="stylesheet"][href]`
-    * `optimize` - list or atom option for optimizing the output. The following values can be used:
+    * `:css_selector` - the style tags to be processed for inline styling, defaults to `style,link[rel="stylesheet"][href]`
+    * `:optimize` - list or atom option for optimizing the output. The following values can be used:
       * `:none` - no optimization (default)
       * `:all` - apply all optimization steps
       * `:remove_style_tags` - Remove style tags (can be combined in a list)
   """
-  @spec process(String.t(), Keyword.t()) :: String.t()
-  def process(html, options \\ []) do
-    css_selector = Keyword.get(options, :css_selector, "style,link[rel=\"stylesheet\"][href]")
+  @spec process(String.t() | HTMLParser.html_tree(), [CSSParser.rule_set()], Keyword.t()) :: String.t()
+  def process(html_or_html_tree, css_rule_sets_or_options \\ nil, options \\ nil)
+  def process(html, css_rule_sets_or_options, options) when is_binary(html) do
+    html
+    |> HTMLParser.parse()
+    |> process(css_rule_sets_or_options, options)
+  end
+  def process(html_tree, css_rule_sets_or_options, nil) do
+    case Keyword.keyword?(css_rule_sets_or_options) do
+      true  -> process(html_tree, nil, css_rule_sets_or_options)
+      false -> process(html_tree, css_rule_sets_or_options, [])
+    end
+  end
+  def process(html_tree, nil, options) do
+    css_selector  = Keyword.get(options, :css_selector, "style,link[rel=\"stylesheet\"][href]")
+    css_rule_sets = load_styles(html_tree, css_selector)
+    options       = Keyword.put_new(options, :css_selector, css_selector)
+
+    process(html_tree, css_rule_sets, options)
+  end
+  def process(html_tree, css_rules_sets, options) do
     optimize_steps = Keyword.get(options, :optimize, :none)
-    tree = HTMLParser.parse(html)
+    optimize_options = Keyword.take(options, [:css_selector])
 
-    tree
-    |> load_styles(css_selector)
-    |> apply_styles(tree)
+    css_rules_sets
+    |> apply_styles(html_tree)
     |> normalize_styles()
-    |> optimize(optimize_steps, css_selector: css_selector)
+    |> optimize(optimize_steps, optimize_options)
     |> HTMLParser.to_string()
   end
 
@@ -37,8 +54,19 @@ defmodule Premailex.HTMLInlineStyles do
     |> Enum.reduce([], &Enum.concat(&1, &2))
   end
 
-  defp apply_styles(styles, tree) do
-    Enum.reduce(styles, tree, &add_rule_set_to_html(&1, &2))
+  defp apply_styles(styles, html_tree) do
+    html_tree
+    |> HTMLParser.all("body")
+    |> case do
+      []   -> html_tree
+      body -> body
+    end
+    |> List.wrap()
+    |> Enum.reduce(html_tree, fn body_or_html_tree, html_tree ->
+      Util.traverse_until_first(html_tree, body_or_html_tree, fn tree ->
+        Enum.reduce(styles, tree, &add_rule_set_to_html(&1, &2))
+      end)
+    end)
   end
 
   defp load_css({"style", _, content}) do
@@ -138,12 +166,13 @@ defmodule Premailex.HTMLInlineStyles do
   defp optimize(tree, [:all], options), do: optimize(tree, [:remove_style_tags], options)
 
   defp optimize(tree, steps, options) do
-    maybe_remove_style_tags(tree, steps, options)
+    maybe_remove_style_tags(tree, steps, Keyword.get(options, :css_selector))
   end
 
-  defp maybe_remove_style_tags(tree, steps, options) do
+  defp maybe_remove_style_tags(tree, _steps, nil), do: tree
+  defp maybe_remove_style_tags(tree, steps, css_selector) do
     case Enum.member?(steps, :remove_style_tags) do
-      true -> HTMLParser.filter(tree, Keyword.get(options, :css_selector))
+      true -> HTMLParser.filter(tree, css_selector)
       false -> tree
     end
   end

test/premailex/html_inline_styles_test.exs

@@ -108,7 +108,7 @@ defmodule Premailex.HTMLInlineStylesTest do
     {:ok, input: @input}
   end
 
-  test "process/1", %{input: input} do
+  test "process/3", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input)
 
     assert parsed =~
@@ -148,46 +148,77 @@ defmodule Premailex.HTMLInlineStylesTest do
     assert parsed =~ "<div class=\"match-order-test-4 same-match\" style=\"color:yellow;\">"
   end
 
-  test "process/1 with css_selector", %{input: input} do
+  test "process/3 with css_selector", %{input: input} do
     parsed =
       Premailex.HTMLInlineStyles.process(input, css_selector: "link[rel=\"stylesheet\"][href]")
 
     assert parsed =~
              "<p style=\"color:#333333;font-family:Arial, sans-serif;font-size:16px;font-weight:bold;line-height:22px;margin:0;padding:0;\">First paragraph"
   end
 
-  test "process/1 with optimize: :all", %{input: input} do
+  test "process/3 with optimize: :all", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input, optimize: :all)
     refute parsed =~ "<style>"
     refute parsed =~ "<link href"
   end
 
-  test "process/1 with optimize: :remove_style_tags", %{input: input} do
+  test "process/3 with optimize: :remove_style_tags", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input, optimize: :remove_style_tags)
     refute parsed =~ "<style>"
     refute parsed =~ "<link href"
   end
 
-  test "process/1 with optimize: [:remove_style_tags]", %{input: input} do
+  test "process/3 with optimize: [:remove_style_tags]", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input, optimize: [:remove_style_tags])
     refute parsed =~ "<style>"
     refute parsed =~ "<link href"
   end
 
-  test "process/1 with optimize: [:unknown]", %{input: input} do
+  test "process/3 with optimize: [:unknown]", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input, optimize: [:unknown])
     assert parsed =~ "<style>"
     assert parsed =~ "<link href"
   end
 
-  test "process/1 with optimize: [:none]", %{input: input} do
+  test "process/3 with optimize: [:none]", %{input: input} do
     parsed = Premailex.HTMLInlineStyles.process(input, optimize: :none)
     assert parsed =~ "<style>"
     assert parsed =~ "<link href"
   end
 
-  test "process/1 with no loaded styles" do
+  test "process/3 with no loaded styles" do
     parsed = Premailex.HTMLInlineStyles.process("<span style=\"width: 100%;\">Hello</span>")
     assert parsed =~ "<span style=\"width: 100%;\">Hello</span>"
   end
+
+  test "process/3 accepts html tree as first argument" do
+    html_tree = Premailex.HTMLParser.parse(@input)
+    parsed = Premailex.HTMLInlineStyles.process(html_tree)
+
+    assert parsed =~ "<style>"
+    assert parsed =~ "<link href"
+    assert parsed =~ "<body style=\"color:#333333;font-family:Arial, sans-serif;font-size:14px;line-height:22px;\">"
+
+    parsed = Premailex.HTMLInlineStyles.process(html_tree, [optimize: :all])
+
+    refute parsed =~ "<style>"
+    refute parsed =~ "<link href"
+    assert parsed =~ "<body style=\"color:#333333;font-family:Arial, sans-serif;font-size:14px;line-height:22px;\">"
+    end
+
+  test "process/3 accepts css rule set as second argument" do
+    css_rule_set = Premailex.CSSParser.parse("*{color:red;}")
+    parsed = Premailex.HTMLInlineStyles.process(@input, css_rule_set)
+
+    assert parsed =~ "<style>"
+    assert parsed =~ "<link href"
+    assert parsed =~ "<body style=\"color:red;\">"
+
+    css_rule_set = Premailex.CSSParser.parse("*{color:red;}")
+    parsed = Premailex.HTMLInlineStyles.process(@input, css_rule_set, [optimize: :all])
+
+    assert parsed =~ "<style>"
+    assert parsed =~ "<link href"
+    assert parsed =~ "<body style=\"color:red;\">"
+  end
 end