news_parse_ex

commit: 3deab222dc3a9ed0e6bbd7d7c3a5e834a6361074
parent fd59c289e863d304403c694419d17bff4927373c
Author: Haelwenn (lanodan) Monnier <contact@hacktivis.me>
Date:   Mon, 26 Dec 2022 15:40:56 +0100

XML: Return tuples for string_from_xpath/2

Diffstat:
M
lib/news_parse_ex.ex
25
++++++++++++-------------
M
lib/xml.ex
19
+++++++------------

2 files changed, 19 insertions(+), 25 deletions(-)
diff --git a/lib/news_parse_ex.ex b/lib/news_parse_ex.ex
@@ -6,24 +6,23 @@ defmodule NewsParseEx do
   alias NewsParseEx.XML
 
   def get_feed_type(doc) do
-    root_name = XML.string_from_xpath(~s[name()], doc)
-
-    if root_name != "feed" do
-      {:error, "XML root isn't <feed> but #{root_name}"}
-    end
-
-    case XML.string_from_xpath(~s[/feed/namespace::*], doc) do
-      "http://www.w3.org/2005/Atom" -> {:ok, :atom}
-      e -> {:error, e}
+    with {_, {:ok, "feed"}} <- {:root_name, XML.string_from_xpath(~s[name()], doc)},
+         {:ok, namespace} <- XML.string_from_xpath(~s[/feed/namespace::*], doc) do
+      case namespace do
+        "http://www.w3.org/2005/Atom" -> {:ok, :atom}
+        e -> {:error, e}
+      end
+    else
+      {:root_name, name} -> {:error, "XML root isn't <feed> but <#{name}>"}
     end
   end
 
-  def get_feed_title(doc, :atom), do: {:ok, XML.string_from_xpath(~s[/feed/title/text()], doc)}
-  def get_feed_id(doc, :atom), do: {:ok, XML.string_from_xpath(~s[/feed/id/text()], doc)}
+  def get_feed_title(doc, :atom), do: XML.string_from_xpath(~s[/feed/title/text()], doc)
+  def get_feed_id(doc, :atom), do: XML.string_from_xpath(~s[/feed/id/text()], doc)
 
   def get_feed_last_update(doc, :atom) do
-    XML.string_from_xpath(~s[/feed/updated/text()], doc)
-    |> DateTime.from_iso8601()
+    {:ok, updated} = XML.string_from_xpath(~s[/feed/updated/text()], doc)
+    DateTime.from_iso8601(updated)
   end
 
   def parse(str) when is_bitstring(str) do
diff --git a/lib/xml.ex b/lib/xml.ex
@@ -1,5 +1,6 @@
 # Pleroma: A lightweight social networking server
 # Copyright © 2017-2022 Pleroma Authors <https://pleroma.social/>
+# Copyright © 2022 Haelwenn (lanodan) Monnier <contact+news_parse_ex@hacktivis.me>
 # SPDX-License-Identifier: AGPL-3.0-only
 
 defmodule NewsParseEx.XML do
@@ -8,20 +9,14 @@ defmodule NewsParseEx.XML do
   def string_from_xpath(_, :error), do: nil
 
   def string_from_xpath(xpath, doc) do
-    try do
-      {:xmlObj, :string, res} = :xmerl_xpath.string('string(#{xpath})', doc)
+    {:xmlObj, :string, res} = :xmerl_xpath.string('string(#{xpath})', doc)
 
-      res =
-        res
-        |> to_string
-        |> String.trim()
+    res =
+      res
+      |> to_string
+      |> String.trim()
 
-      if res == "", do: nil, else: res
-    catch
-      _e ->
-        Logger.debug("Couldn't find xpath #{xpath} in XML doc")
-        nil
-    end
+    {:ok, res}
   end
 
   def parse_document(text) do