Nearly pretty-print subtitle XML (though not in <Text> nodes).

[libdcp.git] / src / subtitle_asset.cc

diff --git a/src/subtitle_asset.cc b/src/subtitle_asset.cc
index 22781196ac5c485ca042ba8813895e06a85db7f1..de6332e6810d17b6c143211d6eaee4af91abcb8b 100644 (file)
--- a/src/subtitle_asset.cc
+++ b/src/subtitle_asset.cc
@@ -54,18 +54,20 @@
 #include <boost/algorithm/string.hpp>
 #include <boost/lexical_cast.hpp>
 #include <boost/shared_array.hpp>
+#include <algorithm>
 
 
-using std::dynamic_pointer_cast;
-using std::string;
-using std::cout;
 using std::cerr;
+using std::cout;
+using std::dynamic_pointer_cast;
+using std::make_shared;
 using std::map;
+using std::pair;
 using std::shared_ptr;
+using std::string;
 using std::vector;
-using std::make_shared;
-using boost::optional;
 using boost::lexical_cast;
+using boost::optional;
 using namespace dcp;
 
 
@@ -799,3 +801,107 @@ SubtitleAsset::fix_empty_font_ids ()
                }
        }
 }
+
+
+struct State
+{
+       int indent;
+       string xml;
+       int disable_formatting;
+};
+
+
+static
+void
+format_xml_node (xmlpp::Node const* node, State& state)
+{
+       if (auto text_node = dynamic_cast<const xmlpp::TextNode*>(node)) {
+               state.xml += text_node->get_content();
+       } else if (auto element = dynamic_cast<const xmlpp::Element*>(node)) {
+               ++state.indent;
+
+               auto children = element->get_children();
+               auto const should_disable_formatting =
+                       std::any_of(
+                               children.begin(), children.end(),
+                               [](xmlpp::Node const* node) { return static_cast<bool>(dynamic_cast<const xmlpp::ContentNode*>(node)); }
+                               ) || element->get_name() == "Text";
+
+               if (!state.disable_formatting) {
+                       state.xml += "\n" + string(state.indent * 2, ' ');
+               }
+
+               state.xml += "<" + element->get_name();
+
+               for (auto attribute: element->get_attributes()) {
+                       state.xml += String::compose(" %1=\"%2\"", attribute->get_name().raw(), attribute->get_value().raw());
+               }
+
+               if (children.empty()) {
+                       state.xml += "/>";
+               } else {
+                       state.xml += ">";
+
+                       if (should_disable_formatting) {
+                               ++state.disable_formatting;
+                       }
+
+                       for (auto child: children) {
+                               format_xml_node(child, state);
+                       }
+
+                       if (!state.disable_formatting) {
+                               state.xml += "\n" + string(state.indent * 2, ' ');
+                       }
+
+                       state.xml += String::compose("</%1>", element->get_name().raw());
+
+                       if (should_disable_formatting) {
+                               --state.disable_formatting;
+                       }
+               }
+
+               --state.indent;
+       }
+}
+
+
+/** Format XML much as write_to_string_formatted() would do, except without adding any white space
+ *  to <Text> nodes.  This is an attempt to avoid changing what is actually displayed as subtitles
+ *  while also formatting the XML in such a way as to avoid DoM bug 2205.
+ *
+ *  namespace is a list of namespaces for the root node; it would be nicer to set these up with
+ *  set_namespace_declaration in the caller and then to extract them here but I couldn't find a way
+ *  to get all namespaces with the libxml++ API.
+ */
+string
+SubtitleAsset::format_xml (xmlpp::Document const& document, vector<pair<string, string>> const& namespaces)
+{
+       auto root = document.get_root_node();
+
+       State state = {};
+       state.xml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<" + root->get_name();
+
+       for (auto const& ns: namespaces) {
+               if (ns.first.empty()) {
+                       state.xml += String::compose(" xmlns=\"%1\"", ns.second);
+               } else {
+                       state.xml += String::compose(" xmlns:%1=\"%2\"", ns.first, ns.second);
+               }
+       }
+
+       for (auto attribute: root->get_attributes()) {
+               state.xml += String::compose(" %1=\"%2\"", attribute->get_name().raw(), attribute->get_value().raw());
+       }
+
+       state.xml += ">";
+
+       for (auto child: document.get_root_node()->get_children()) {
+               format_xml_node(child, state);
+       }
+
+       state.xml += String::compose("\n</%1>\n", root->get_name().raw());
+
+       return state.xml;
+}
+