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lib/phoenix/router/path.ex

defmodule Phoenix.Router.Path do
def split(path), do: String.split(path, "/")
def join([]), do: ""
def join(split_path), do: Elixir.Path.join(split_path)
def split_from_conn(conn) do
conn.path_info |> join |> split
end
@doc """
Returns the AST binding of the given variable with var_name
var_name - The String or Atom variable name to be bound
# Examples
iex> Phoenix.Router.Path.var_ast("my_var")
{:var!, [context: Phoenix.Router.Path, import: Kernel], [:my_var]}
iex> Phoenix.Router.Path.var_ast(:my_var)
{:var!, [context: Phoenix.Router.Path, import: Kernel], [:my_var]}
"""
def var_ast(var_name) when is_binary(var_name) do
var_ast(binary_to_atom(var_name))
end
def var_ast(var_name) do
quote do: var!(unquote(var_name))
end
@doc """
Splits parameterized String path into list of arguments for defmatch route.
Named params beginning with ":" are injected into the argument list as
an AST binding matching the param name.
Examples
iex> Path.matched_arg_list_with_ast_bindings("users/:user_id/comments/:id")
["users", {:var!, [context: Phoenix.Router.Path, import: Kernel], [:user_id]},
"comments", {:var!, [context: Phoenix.Router.Path, import: Kernel], [:id]}]
iex> Path.matched_arg_list_with_ast_bindings("/pages")
["pages"]
iex> Path.matched_arg_list_with_ast_bindings("/")
[""]
Generated as:
def match(:get, ["users", user_id, "comments", id])
"""
def matched_arg_list_with_ast_bindings(path) do
path
|> ensure_no_leading_slash
|> split
|> Enum.chunk(2, 1, [nil])
|> Enum.map(fn [part, next] -> part_to_ast_binding(part, next) end)
|> Enum.filter(fn part -> part end)
end
defp part_to_ast_binding(<<"*" <> _splat_name>>, nil), do: nil
defp part_to_ast_binding(<<":" <> param_name>>, <<"*" <> splat_name>>) do
{:|, [], [var_ast(param_name), var_ast(splat_name)]}
end
defp part_to_ast_binding(<<":" <> param_name>>, _next) do
var_ast(param_name)
end
defp part_to_ast_binding(part, <<"*" <> splat_name>>) do
{:|, [], [part, var_ast(splat_name)]}
end
defp part_to_ast_binding(part, _next), do: part
@doc """
Returns Keyword List of parameters from URL matched with
AST of associationed bindings for inclusion in defmatch route
Examples
iex> Path.params_with_ast_bindings("users/:user_id/comments/:id")
[{"user_id", {:var!, [context: Phoenix.Router.Path, import: Kernel], [:user_id]}},
{"id", {:var!, [context: Phoenix.Router.Path, import: Kernel], [:id]}}]
"""
def params_with_ast_bindings(path) do
Enum.zip(param_names(path), matched_param_ast_bindings(path))
end
def matched_param_ast_bindings(path) do
path
|> split
|> Enum.map(fn
<<":" <> param>> -> var_ast(param)
<<"*" <> param>> -> quote do: Phoenix.Router.Path.join(unquote(var_ast(param)))
_part ->
end)
|> Enum.filter(&is_tuple(&1))
end
@doc """
Returns List of atoms of contained named parameters in route
Examples
iex> Phoenix.Router.Path.param_names("users/:user_id/comments/:id")
["user_id", "id"]
iex> Phoenix.Router.Path.param_names("/pages/about")
[]
"""
def param_names(path) do
Regex.scan(~r/[\:\*]{1}\w+/, path)
|> List.flatten
|> Enum.map(&String.strip(&1, ?:))
|> Enum.map(&String.strip(&1, ?*))
end
@doc """
Builds String Path replacing named params with keyword list of values
# Examples
iex> Path.build("users/:user_id/comments/:id", user_id: 1, id: 123)
"/users/1/comments/123"
iex> Path.build("pages/about", [])
"/pages/about"
"""
def build(path, []), do: ensure_leading_slash(path)
def build(path, param_values) do
path
|> param_names
|> replace_param_names_with_values(param_values, path)
|> ensure_leading_slash
end
defp replace_param_names_with_values(param_names, param_values, path) do
Enum.reduce param_names, path, fn param_name, path_acc ->
value = param_values[binary_to_atom(param_name)] |> to_string
String.replace(path_acc, ~r/[\:\*]{1}#{param_name}/, value)
end
end
@doc """
Adds leading forward slash to string path if missing
# Examples
iex> Path.ensure_leading_slash("users/1")
"/users/1"
iex> Path.ensure_leading_slash("/users/2")
"/users/2"
"""
def ensure_leading_slash(path = <<"/" <> _rest>>), do: path
def ensure_leading_slash(path), do: "/" <> path
@doc """
Removes leading forward slash from string path if present
# Examples
iex> Path.ensure_no_leading_slash("users/1")
"users/1"
iex> Path.ensure_no_leading_slash("/users/2")
"users/2"
"""
def ensure_no_leading_slash(<<"/" <> rest>>), do: rest
def ensure_no_leading_slash(path), do: path
end