Added plurals and context support to Translation

core/compressed_translation.cpp

@@ -43,6 +43,8 @@ struct _PHashTranslationCmp {
 };
 
 void PHashTranslation::generate(const Ref<Translation> &p_from) {
+	// This method compresses a Translation instance.
+	// Right now it doesn't handle context or plurals, so Translation subclasses using plurals or context (i.e TranslationPO) shouldn't be compressed.
 #ifdef TOOLS_ENABLED
 	List<StringName> keys;
 	p_from->get_message_list(&keys);
@@ -212,7 +214,9 @@ bool PHashTranslation::_get(const StringName &p_name, Variant &r_ret) const {
 	return true;
 }
 
-StringName PHashTranslation::get_message(const StringName &p_src_text) const {
+StringName PHashTranslation::get_message(const StringName &p_src_text, const StringName &p_context) const {
+	// p_context passed in is ignore. The use of context is not yet supported in PHashTranslation.
+
 	int htsize = hash_table.size();
 
 	if (htsize == 0) {
@@ -267,6 +271,11 @@ StringName PHashTranslation::get_message(const StringName &p_src_text) const {
 	}
 }
 
+StringName PHashTranslation::get_plural_message(const StringName &p_src_text, const StringName &p_plural_text, int p_n, const StringName &p_context) const {
+	// The use of plurals translation is not yet supported in PHashTranslation.
+	return get_message(p_src_text, p_context);
+}
+
 void PHashTranslation::_get_property_list(List<PropertyInfo> *p_list) const {
 	p_list->push_back(PropertyInfo(Variant::PACKED_INT32_ARRAY, "hash_table"));
 	p_list->push_back(PropertyInfo(Variant::PACKED_INT32_ARRAY, "bucket_table"));

core/compressed_translation.h

@@ -79,7 +79,8 @@ class PHashTranslation : public Translation {
 	static void _bind_methods();
 
 public:
-	virtual StringName get_message(const StringName &p_src_text) const override; //overridable for other implementations
+	virtual StringName get_message(const StringName &p_src_text, const StringName &p_context = "") const override; //overridable for other implementations
+	virtual StringName get_plural_message(const StringName &p_src_text, const StringName &p_plural_text, int p_n, const StringName &p_context = "") const override;
 	void generate(const Ref<Translation> &p_from);
 
 	PHashTranslation() {}

core/io/translation_loader_po.cpp

@@ -32,26 +32,34 @@
 
 #include "core/os/file_access.h"
 #include "core/translation.h"
+#include "core/translation_po.h"
 
 RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error) {
 	enum Status {
 		STATUS_NONE,
 		STATUS_READING_ID,
 		STATUS_READING_STRING,
+		STATUS_READING_CONTEXT,
+		STATUS_READING_PLURAL,
 	};
 
 	Status status = STATUS_NONE;
 
 	String msg_id;
 	String msg_str;
+	String msg_context;
+	Vector<String> msgs_plural;
 	String config;
 
 	if (r_error) {
 		*r_error = ERR_FILE_CORRUPT;
 	}
 
-	Ref<Translation> translation = Ref<Translation>(memnew(Translation));
+	Ref<TranslationPO> translation = Ref<TranslationPO>(memnew(TranslationPO));
 	int line = 1;
+	int plural_forms = 0;
+	int plural_index = -1;
+	bool entered_context = false;
 	bool skip_this = false;
 	bool skip_next = false;
 	bool is_eof = false;
@@ -63,40 +71,107 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error) {
 
 		// If we reached last line and it's not a content line, break, otherwise let processing that last loop
 		if (is_eof && l.empty()) {
-			if (status == STATUS_READING_ID) {
+			if (status == STATUS_READING_ID || status == STATUS_READING_CONTEXT || (status == STATUS_READING_PLURAL && plural_index != plural_forms - 1)) {
 				memdelete(f);
-				ERR_FAIL_V_MSG(RES(), "Unexpected EOF while reading 'msgid' at: " + path + ":" + itos(line));
+				ERR_FAIL_V_MSG(RES(), "Unexpected EOF while reading PO file at: " + path + ":" + itos(line));
 			} else {
 				break;
 			}
 		}
 
-		if (l.begins_with("msgid")) {
+		if (l.begins_with("msgctxt")) {
+			if (status != STATUS_READING_STRING && status != STATUS_READING_PLURAL) {
+				memdelete(f);
+				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgctxt', was expecting 'msgid_plural' or 'msgstr' before 'msgctxt' while parsing: " + path + ":" + itos(line));
+			}
+
+			// In PO file, "msgctxt" appears before "msgid". If we encounter a "msgctxt", we add what we have read
+			// and set "entered_context" to true to prevent adding twice.
+			if (!skip_this && msg_id != "") {
+				if (status == STATUS_READING_STRING) {
+					translation->add_message(msg_id, msg_str, msg_context);
+				} else if (status == STATUS_READING_PLURAL) {
+					if (plural_index != plural_forms - 1) {
+						memdelete(f);
+						ERR_FAIL_V_MSG(RES(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+					}
+					translation->add_plural_message(msg_id, msgs_plural, msg_context);
+				}
+			}
+			msg_context = "";
+			l = l.substr(7, l.length()).strip_edges();
+			status = STATUS_READING_CONTEXT;
+			entered_context = true;
+		}
+
+		if (l.begins_with("msgid_plural")) {
+			if (plural_forms == 0) {
+				memdelete(f);
+				ERR_FAIL_V_MSG(RES(), "PO file uses 'msgid_plural' but 'Plural-Forms' is invalid or missing in header: " + path + ":" + itos(line));
+			} else if (status != STATUS_READING_ID) {
+				memdelete(f);
+				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgid_plural', was expecting 'msgid' before 'msgid_plural' while parsing: " + path + ":" + itos(line));
+			}
+			// We don't record the message in "msgid_plural" itself as tr_n(), TTRN(), RTRN() interfaces provide the plural string already.
+			// We just have to reset variables related to plurals for "msgstr[]" later on.
+			l = l.substr(12, l.length()).strip_edges();
+			plural_index = -1;
+			msgs_plural.clear();
+			msgs_plural.resize(plural_forms);
+			status = STATUS_READING_PLURAL;
+		} else if (l.begins_with("msgid")) {
 			if (status == STATUS_READING_ID) {
 				memdelete(f);
 				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgid', was expecting 'msgstr' while parsing: " + path + ":" + itos(line));
 			}
 
 			if (msg_id != "") {
-				if (!skip_this) {
-					translation->add_message(msg_id, msg_str);
+				if (!skip_this && !entered_context) {
+					if (status == STATUS_READING_STRING) {
+						translation->add_message(msg_id, msg_str, msg_context);
+					} else if (status == STATUS_READING_PLURAL) {
+						if (plural_index != plural_forms - 1) {
+							memdelete(f);
+							ERR_FAIL_V_MSG(RES(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+						}
+						translation->add_plural_message(msg_id, msgs_plural, msg_context);
+					}
 				}
 			} else if (config == "") {
 				config = msg_str;
+				// Record plural rule.
+				int p_start = config.find("Plural-Forms");
+				if (p_start != -1) {
+					int p_end = config.find("\n", p_start);
+					translation->set_plural_rule(config.substr(p_start, p_end - p_start));
+					plural_forms = translation->get_plural_forms();
+				}
 			}
 
 			l = l.substr(5, l.length()).strip_edges();
 			status = STATUS_READING_ID;
+			// If we did not encounter msgctxt, we reset context to empty to reset it.
+			if (!entered_context) {
+				msg_context = "";
+			}
 			msg_id = "";
 			msg_str = "";
 			skip_this = skip_next;
 			skip_next = false;
+			entered_context = false;
 		}
 
-		if (l.begins_with("msgstr")) {
+		if (l.begins_with("msgstr[")) {
+			if (status != STATUS_READING_PLURAL) {
+				memdelete(f);
+				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgstr[]', was expecting 'msgid_plural' before 'msgstr[]' while parsing: " + path + ":" + itos(line));
+			}
+			plural_index++; // Increment to add to the next slot in vector msgs_plural.
+			l = l.substr(9, l.length()).strip_edges();
+		} else if (l.begins_with("msgstr")) {
 			if (status != STATUS_READING_ID) {
 				memdelete(f);
-				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgstr', was expecting 'msgid' while parsing: " + path + ":" + itos(line));
+				ERR_FAIL_V_MSG(RES(), "Unexpected 'msgstr', was expecting 'msgid' before 'msgstr' while parsing: " + path + ":" + itos(line));
 			}
 
 			l = l.substr(6, l.length()).strip_edges();
@@ -108,7 +183,7 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error) {
 				skip_next = true;
 			}
 			line++;
-			continue; //nothing to read or comment
+			continue; // Nothing to read or comment.
 		}
 
 		if (!l.begins_with("\"") || status == STATUS_NONE) {
@@ -146,23 +221,36 @@ RES TranslationLoaderPO::load_translation(FileAccess *f, Error *r_error) {
 
 		if (status == STATUS_READING_ID) {
 			msg_id += l;
-		} else {
+		} else if (status == STATUS_READING_STRING) {
 			msg_str += l;
+		} else if (status == STATUS_READING_CONTEXT) {
+			msg_context += l;
+		} else if (status == STATUS_READING_PLURAL && plural_index >= 0) {
+			msgs_plural.write[plural_index] = msgs_plural[plural_index] + l;
 		}
 
 		line++;
 	}
 
 	memdelete(f);
 
+	// Add the last set of data from last iteration.
 	if (status == STATUS_READING_STRING) {
 		if (msg_id != "") {
 			if (!skip_this) {
-				translation->add_message(msg_id, msg_str);
+				translation->add_message(msg_id, msg_str, msg_context);
 			}
 		} else if (config == "") {
 			config = msg_str;
 		}
+	} else if (status == STATUS_READING_PLURAL) {
+		if (!skip_this && msg_id != "") {
+			if (plural_index != plural_forms - 1) {
+				memdelete(f);
+				ERR_FAIL_V_MSG(RES(), "Number of 'msgstr[]' doesn't match with number of plural forms: " + path + ":" + itos(line));
+			}
+			translation->add_plural_message(msg_id, msgs_plural, msg_context);
+		}
 	}
 
 	ERR_FAIL_COND_V_MSG(config == "", RES(), "No config found in file: " + path + ".");

core/object.cpp

@@ -1432,12 +1432,22 @@ void Object::initialize_class() {
 	initialized = true;
 }
 
-StringName Object::tr(const StringName &p_message) const {
+String Object::tr(const StringName &p_message, const StringName &p_context) const {
 	if (!_can_translate || !TranslationServer::get_singleton()) {
 		return p_message;
 	}
+	return TranslationServer::get_singleton()->translate(p_message, p_context);
+}
 
-	return TranslationServer::get_singleton()->translate(p_message);
+String Object::tr_n(const StringName &p_message, const StringName &p_message_plural, int p_n, const StringName &p_context) const {
+	if (!_can_translate || !TranslationServer::get_singleton()) {
+		// Return message based on English plural rule if translation is not possible.
+		if (p_n == 1) {
+			return p_message;
+		}
+		return p_message_plural;
+	}
+	return TranslationServer::get_singleton()->translate_plural(p_message, p_message_plural, p_n, p_context);
 }
 
 void Object::_clear_internal_resource_paths(const Variant &p_var) {
@@ -1578,7 +1588,8 @@ void Object::_bind_methods() {
 
 	ClassDB::bind_method(D_METHOD("set_message_translation", "enable"), &Object::set_message_translation);
 	ClassDB::bind_method(D_METHOD("can_translate_messages"), &Object::can_translate_messages);
-	ClassDB::bind_method(D_METHOD("tr", "message"), &Object::tr);
+	ClassDB::bind_method(D_METHOD("tr", "message", "context"), &Object::tr, DEFVAL(""));
+	ClassDB::bind_method(D_METHOD("tr_n", "message", "plural_message", "n", "context"), &Object::tr_n, DEFVAL(""));
 
 	ClassDB::bind_method(D_METHOD("is_queued_for_deletion"), &Object::is_queued_for_deletion);
 

core/object.h

@@ -719,7 +719,8 @@ class Object {
 
 	virtual void get_argument_options(const StringName &p_function, int p_idx, List<String> *r_options) const;
 
-	StringName tr(const StringName &p_message) const; // translate message (internationalization)
+	String tr(const StringName &p_message, const StringName &p_context = "") const; // translate message (internationalization)
+	String tr_n(const StringName &p_message, const StringName &p_message_plural, int p_n, const StringName &p_context = "") const;
 
 	bool _is_queued_for_deletion = false; // set to true by SceneTree::queue_delete()
 	bool is_queued_for_deletion() const;