context: Prepare shared json option

For requesting machine-readable output in JSON format.

dnf5/context.cpp

@@ -173,6 +173,9 @@ class Context::Impl {
     void set_should_store_offline(bool should_store_offline) { this->should_store_offline = should_store_offline; }
     bool get_should_store_offline() const { return should_store_offline; }
 
+    void set_json_output_requested(bool json_output) { this->json_output = json_output; }
+    bool get_json_output_requested() const { return json_output; }
+
     libdnf5::Base & get_base() { return base; };
 
     std::vector<std::pair<std::string, std::string>> & get_setopts() { return setopts; }
@@ -206,6 +209,7 @@ class Context::Impl {
     const char * comment{nullptr};
 
     bool should_store_offline = false;
+    bool json_output = false;
 
     bool quiet{false};
     bool dump_main_config{false};
@@ -658,6 +662,14 @@ bool Context::get_should_store_offline() const {
     return p_impl->get_should_store_offline();
 }
 
+void Context::set_json_output_requested(bool json_output) {
+    p_impl->set_json_output_requested(json_output);
+}
+
+bool Context::get_json_output_requested() const {
+    return p_impl->get_json_output_requested();
+}
+
 libdnf5::Base & Context::get_base() {
     return p_impl->get_base();
 };

dnf5/include/dnf5/context.hpp

@@ -149,6 +149,9 @@ class Context : public libdnf5::cli::session::Session {
     void set_should_store_offline(bool should_store_offline);
     bool get_should_store_offline() const;
 
+    void set_json_output_requested(bool json_output);
+    bool get_json_output_requested() const;
+
     libdnf5::Base & get_base();
 
     std::vector<std::pair<std::string, std::string>> & get_setopts();

dnf5/include/dnf5/shared_options.hpp

@@ -63,10 +63,12 @@ void create_downloadonly_option(dnf5::Command & command);
 /// The value is stored in Context::transaction_store_path.
 void create_store_option(dnf5::Command & command);
 
-
 /// Create the `--offline` option for a command provided as an argument.
 void create_offline_option(dnf5::Command & command);
 
+/// Create the `--json` option for a command provided as an argument.
+void create_json_option(dnf5::Command & command);
+
 }  // namespace dnf5
 
 #endif  // DNF5_COMMANDS_SHARED_OPTIONS_HPP

dnf5/shared_options.cpp

@@ -139,5 +139,22 @@ void create_store_option(dnf5::Command & command) {
     });
 }
 
+void create_json_option(dnf5::Command & command) {
+    auto & ctx = command.get_context();
+    auto & parser = command.get_context().get_argument_parser();
+    auto json = parser.add_new_named_arg("json");
+    json->set_long_name("json");
+    json->set_description("Request json output format");
+    json->set_const_value("true");
+    json->set_parse_hook_func([&ctx](
+                                  [[maybe_unused]] libdnf5::cli::ArgumentParser::NamedArg * arg,
+                                  [[maybe_unused]] const char * option,
+                                  [[maybe_unused]] const char * value) {
+        ctx.set_json_output_requested(true);
+        return true;
+    });
+    command.get_argument_parser_command()->register_named_arg(json);
+}
+
 
 }  // namespace dnf5