Added RSS export.

README.adoc

@@ -5,8 +5,8 @@
  an URI to the archived version, the current date and time, title, description,
  the full text of the page and optional tags.
 
-The database can be filtered by time, tags and full text and exported to CSV or
-AsciiDoc.
+The database can be filtered by time, tags and full text and exported to CSV,
+AsciiDoc, JSON or RSS.
 
 Archiving is done using the Wayback machine from the
 https://archive.org/[Internet Archive].

cmake/remwhareadConfig.cmake.in

@@ -2,7 +2,7 @@ include(CMakeFindDependencyMacro)
 include(GNUInstallDirs)
 
 find_depencency(Poco
-  COMPONENTS Foundation Net NetSSL Data DataSQLite JSON
+  COMPONENTS Foundation Net NetSSL Data DataSQLite JSON XML
   CONFIG REQUIRED)
 find_dependency(PkgConfig REQUIRED)
 pkg_check_modules(libxdg-basedir REQUIRED IMPORTED_TARGET libxdg-basedir)

include/export/rss.hpp

@@ -0,0 +1,46 @@
+/*  This file is part of remwharead.
+ *  Copyright © 2019 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef REMWHAREAD_RSS_HPP
+#define REMWHAREAD_RSS_HPP
+
+#include <string>
+#include "export.hpp"
+
+namespace remwharead
+{
+namespace Export
+{
+    using std::string;
+
+    /*!
+     *  @brief  Export as RSS feed.
+     *
+     *  @since  0.8.0
+     *
+     *  @headerfile rss.hpp remwharead/export/rss.hpp
+     */
+    class RSS : protected ExportBase
+    {
+    public:
+        using ExportBase::ExportBase;
+
+        virtual void print() const override;
+    };
+}
+}
+
+#endif  // REMWHAREAD_RSS_HPP

include/remwharead.hpp

@@ -45,6 +45,7 @@
 #include "export/export.hpp"
 #include "export/simple.hpp"
 #include "export/json.hpp"
+#include "export/rss.hpp"
 #include "search.hpp"
 #include "sqlite.hpp"
 #include "time.hpp"

include/types.hpp

@@ -35,7 +35,8 @@ namespace remwharead
         asciidoc,
         bookmarks,
         simple,
-        json
+        json,
+        rss
     };
 }
 

man/remwharead.1.adoc

@@ -2,7 +2,7 @@
 :doctype:       manpage
 :Author:        tastytea
 :Email:         tastytea@tastytea.de
-:Date:          2019-09-03
+:Date:          2019-09-06
 :Revision:      0.0.0
 :man source:    remwharead
 :man manual:    General Commands Manual
@@ -24,7 +24,7 @@ remwharead - Saves URIs of things you want to remember in a database
  the full text of the page and optional tags.
 
 The database can be filtered by time, tags and full text and exported to CSV,
-AsciiDoc, a bookmarks file or JSON.
+AsciiDoc, a bookmarks file, JSON or RSS.
 
 Archiving is done using the Wayback machine from the
 https://archive.org/[Internet Archive].
@@ -36,7 +36,7 @@ Add tags to _URI_, delimited by commas.
 
 *-e* _format_, *--export* _format_::
 Export to _format_. Possible values are _csv_, _asciidoc_, _bookmarks_,
-_simple_ or _json_. See _FORMATS_.
+_simple_, _json_ or _rss_. See _FORMATS_.
 
 *-f* _file_, *--file* _file_::
 Save output to _file_. Default is stdout.
@@ -139,13 +139,19 @@ Export as JSON array. See https://tools.ietf.org/html/rfc8259[RFC 8259]. Each
 object contains the members _uri_, _archive_uri_, _datetime_, _tags_ (array),
 _title_, _description_ and _fulltext_.
 
+=== rss
+
+Export as http://www.rssboard.org/rss-specification[RSS] feed. Because the URL
+of the feed is unknown to *remwharead*, the generated feed is slightly out of
+specification (the element _link_ in _channel_ is empty).
+
 == SEARCH EXPRESSIONS
 
 A search expression is either a single term, or several terms separated by _AND_
 or _OR_. _AND_ takes precedence. The expression _Mountain AND Big OR Vegetable_
-finds all things that have either Mountain and Big, or Vegetable in them. You can
-use _||_ instead of _OR_ and _&&_ instead of _AND_. Note that *--search-tags*
-only matches whole tags, Pill does not match Pillow.
+finds all things that have either Mountain and Big, or Vegetable in them. You
+can use _||_ instead of _OR_ and _&&_ instead of _AND_. Note that
+*--search-tags* only matches whole tags, Pill does not match Pillow.
 
 == PROTOCOL SUPPORT
 

pkg-config/remwharead.pc.in

@@ -10,4 +10,4 @@ Version: @PROJECT_VERSION@
 Cflags: -I${includedir}
 Libs: -L${libdir} -l${name} -lPocoData -lstdc++fs
 Requires.private: libxdg-basedir, icu-uc, icu-i18n
-Libs.private: -lPocoFoundation -lPocoNet -lPocoNetSSL -lPocoDataSQLite -lPocoJSON
+Libs.private: -lPocoFoundation -lPocoNet -lPocoNetSSL -lPocoDataSQLite -lPocoJSON -lPocoXML

src/cli/main.cpp

@@ -29,6 +29,7 @@
 #include "export/bookmarks.hpp"
 #include "export/simple.hpp"
 #include "export/json.hpp"
+#include "export/rss.hpp"
 #include "search.hpp"
 
 using namespace remwharead;
@@ -191,6 +192,19 @@ int App::main(const std::vector<std::string> &args)
             }
             break;
         }
+        case export_format::rss:
+        {
+            if (file.is_open())
+            {
+                Export::RSS(entries, file).print();
+                file.close();
+            }
+            else
+            {
+                Export::RSS(entries).print();
+            }
+            break;
+        }
         default:
         {
             break;

src/cli/parse_options.cpp

@@ -143,6 +143,10 @@ void App::handle_options(const std::string &name, const std::string &value)
         {
             _format = export_format::json;
         }
+        else if (value == "rss")
+        {
+            _format = export_format::rss;
+        }
         else
         {
             cerr << "Error: Unknown format.\n";

src/lib/CMakeLists.txt

@@ -3,7 +3,9 @@ include(GNUInstallDirs)
 find_package(PkgConfig REQUIRED)
 pkg_check_modules(libxdg-basedir REQUIRED IMPORTED_TARGET libxdg-basedir)
 # Some distributions do not contain Poco*Config.cmake recipes.
-find_package(Poco COMPONENTS Foundation Net NetSSL Data DataSQLite JSON CONFIG)
+find_package(Poco
+  COMPONENTS Foundation Net NetSSL Data DataSQLite JSON XML
+  CONFIG)
 
 file(GLOB_RECURSE sources_lib *.cpp)
 file(GLOB_RECURSE headers_lib ../../include/*.hpp)
@@ -28,7 +30,8 @@ target_link_libraries(${PROJECT_NAME}
 # If no Poco*Config.cmake recipes are found, look for headers in standard dirs.
 if(PocoNetSSL_FOUND)
   target_link_libraries(${PROJECT_NAME}
-    PRIVATE Poco::Foundation Poco::Net Poco::NetSSL Poco::DataSQLite Poco::JSON
+    PRIVATE Poco::Foundation Poco::Net Poco::NetSSL Poco::DataSQLite
+    Poco::JSON Poco::XML
     PUBLIC Poco::Data)
 else()
   find_file(Poco_h NAMES "Poco/Poco.h"
@@ -42,7 +45,7 @@ else()
       "but the files seem to be in the standard directories. "
       "Let's hope this works.")
     target_link_libraries(${PROJECT_NAME}
-      PRIVATE PocoFoundation PocoNet PocoNetSSL PocoDataSQLite PocoJSON
+      PRIVATE PocoFoundation PocoNet PocoNetSSL PocoDataSQLite PocoJSON PocoXML
       PUBLIC PocoData)
   endif()
 endif()

src/lib/export/rss.cpp

@@ -0,0 +1,139 @@
+/*  This file is part of remwharead.
+ *  Copyright © 2019 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <ctime>
+#include <Poco/XML/XMLWriter.h>
+#include <Poco/SAX/AttributesImpl.h>
+#include <Poco/DateTime.h>
+#include <Poco/DateTimeFormatter.h>
+#include <Poco/Timestamp.h>
+#include "time.hpp"
+#include "version.hpp"
+#include "export/rss.hpp"
+
+namespace remwharead
+{
+    using std::cerr;
+    using std::endl;
+    using std::time_t;
+    using Poco::XML::XMLWriter;
+    using Poco::XML::AttributesImpl;
+    using Poco::DateTime;
+    using Poco::DateTimeFormatter;
+    using Poco::Timestamp;
+
+    void Export::RSS::print() const
+    {
+        try
+        {
+            XMLWriter writer(_out, XMLWriter::CANONICAL);
+            AttributesImpl attrs_rss, attrs_guid;
+            constexpr char timefmt_rfc822[] = "%w, %d %b %Y %H:%M:%S %Z";
+
+            attrs_rss.addAttribute("", "", "version", "", "2.0");
+            attrs_rss.addAttribute("", "", "xmlns:atom", "",
+                                   "http://www.w3.org/2005/Atom");
+            attrs_guid.addAttribute("", "", "isPermaLink", "", "false");
+
+            writer.startDocument();
+            writer.startElement("", "", "rss", attrs_rss);
+            writer.startElement("", "", "channel");
+
+            writer.startElement("", "", "title");
+            writer.characters("Visited things");
+            writer.endElement("", "", "title");
+
+            writer.startElement("", "", "link");
+            // FIXME: There has to be an URL here.
+            writer.endElement("", "", "link");
+
+            writer.startElement("", "", "description");
+            writer.characters("Export from remwharead.");
+            writer.endElement("", "", "description");
+
+            writer.startElement("", "", "generator");
+            writer.characters(string("remwharead ") + global::version);
+            writer.endElement("", "", "generator");
+
+            const string now = DateTimeFormatter::format(DateTime(),
+                                                         timefmt_rfc822);
+            writer.startElement("", "", "lastBuildDate");
+            writer.characters(now);
+            writer.endElement("", "", "lastBuildDate");
+
+            for (const Database::entry &entry : _entries)
+            {
+                writer.startElement("", "", "item");
+
+                writer.startElement("", "", "title");
+                writer.characters(entry.title);
+                writer.endElement("", "", "title");
+
+                writer.startElement("", "", "link");
+                writer.characters(entry.uri);
+                writer.endElement("", "", "link");
+
+                writer.startElement("", "", "guid", attrs_guid);
+                writer.characters(entry.uri + " at " +
+                                  timepoint_to_string(entry.datetime));
+                writer.endElement("", "", "guid");
+
+                const time_t time = system_clock::to_time_t(entry.datetime);
+                const string time_visited = DateTimeFormatter::format(
+                    Timestamp::fromEpochTime(time), timefmt_rfc822);
+                writer.startElement("", "", "pubDate");
+                writer.characters(time_visited);
+                writer.endElement("", "", "pubDate");
+
+                string description = entry.description;
+                if (!description.empty())
+                {
+                    description += "\n\n";
+                }
+                if (!entry.tags.empty())
+                {
+                    description += "Tags: ";
+                    for (const string &tag : entry.tags)
+                    {
+                        description += tag;
+                        if (tag != *(entry.tags.rbegin()))
+                        {
+                            description += ", ";
+                        }
+                    }
+                }
+                if (!entry.archive_uri.empty())
+                {
+                    description += "\n\nArchived version: " + entry.archive_uri;
+                }
+                writer.startElement("", "", "description");
+                writer.characters(description);
+                writer.endElement("", "", "description");
+
+                writer.endElement("", "", "item");
+            }
+
+            writer.endElement("", "", "channel");
+            writer.endElement("", "", "rss");
+            writer.endDocument();
+            _out << endl;
+        }
+        catch (std::exception &e)
+        {
+            cerr << "Error in " << __func__ << ": " << e.what() << endl;
+        }
+    }
+}