@spec traverse(html_tree(), needle(), function()) ::
  html_tree() | {:halt, html_tree()}

Traverses tree searching for needle, and will call provided function on any occurances.

If the function returns {:halt, any}, traverse will stop, and result will be {:halt, html_tree}.

Examples

iex> Premailex.Util.traverse({"div", [], [{"p", [], ["First paragraph"]}, {"p", [], ["Second paragraph"]}]}, "p", fn {name, attrs, _children} -> {name, attrs, ["Updated"]} end)
{"div", [], [{"p", [], ["Updated"]}, {"p", [], ["Updated"]}]}

iex> Premailex.Util.traverse({"div", [], [{"p", [], ["First paragraph"]}, {"p", [], ["Second paragraph"]}]}, {"p", [], ["Second paragraph"]}, fn {name, attrs, _children} -> {name, attrs, ["Updated"]} end)
{"div", [], [{"p", [], ["First paragraph"]}, {"p", [], ["Updated"]}]}

iex> Premailex.Util.traverse({"div", [], [{:comment, "This is a comment"}, {"p", [], ["Paragraph"]}]}, :comment, fn {:comment, _comment} -> {:comment, "Updated"} end)
{"div", [], [{:comment, "Updated"}, {"p", [], ["Paragraph"]}]}

@spec traverse_reduce(list(), needle(), function()) :: {html_tree(), integer()}

Traverse all trees in array searching for needle, and will call function with element and number times needle has been found so far.

Examples

iex> Premailex.Util.traverse_reduce([{"p", [], ["First paragraph"]}, {"p", [], ["Second paragraph"]}], "p", fn({name, attrs, _children}, acc) -> {name, attrs, ["Updated " <> to_string(acc)]} end)
{[{"p", [], ["Updated 0"]}, {"p", [], ["Updated 1"]}], 2}

@spec traverse_until_first(html_tree(), needle(), function()) :: html_tree()

Traverses tree until first match for needle.

Examples

iex> Premailex.Util.traverse_until_first({"div", [], [{"p", [], ["First paragraph"]}, {"p", [], ["Second paragraph"]}]}, "p", fn {name, attrs, _children} -> {name, attrs, ["Updated"]} end)
{"div", [], [{"p", [], ["Updated"]}, {"p", [], ["Second paragraph"]}]}