Separate output into its own module

blueprintcompiler/outputs/xml/xml_emitter.py

@@ -0,0 +1,73 @@
+# xml_emitter.py
+#
+# Copyright 2021 James Westman <james@jwestman.net>
+#
+# This file is free software; you can redistribute it and/or modify it
+# under the terms of the GNU Lesser General Public License as
+# published by the Free Software Foundation; either version 3 of the
+# License, or (at your option) any later version.
+#
+# This file 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+# SPDX-License-Identifier: LGPL-3.0-or-later
+
+from xml.sax import saxutils
+
+from blueprintcompiler.gir import GirType
+from blueprintcompiler.language.types import ClassName
+
+
+class XmlEmitter:
+    def __init__(self, indent=2):
+        self.indent = indent
+        self.result = '<?xml version="1.0" encoding="UTF-8"?>'
+        self._tag_stack = []
+        self._needs_newline = False
+
+    def start_tag(self, tag, **attrs: str | GirType | ClassName | bool | None):
+        self._indent()
+        self.result += f"<{tag}"
+        for key, val in attrs.items():
+            if val is not None:
+                self.result += f' {key.replace("_", "-")}="{saxutils.escape(self._to_string(val))}"'
+        self.result += ">"
+        self._tag_stack.append(tag)
+        self._needs_newline = False
+
+    def put_self_closing(self, tag, **attrs):
+        self._indent()
+        self.result += f"<{tag}"
+        for key, val in attrs.items():
+            if val is not None:
+                self.result += f' {key.replace("_", "-")}="{saxutils.escape(self._to_string(val))}"'
+        self.result += "/>"
+        self._needs_newline = True
+
+    def end_tag(self):
+        tag = self._tag_stack.pop()
+        if self._needs_newline:
+            self._indent()
+        self.result += f"</{tag}>"
+        self._needs_newline = True
+
+    def put_text(self, text: str | int | float):
+        self.result += saxutils.escape(str(text))
+        self._needs_newline = False
+
+    def _indent(self):
+        if self.indent is not None:
+            self.result += "\n" + " " * (self.indent * len(self._tag_stack))
+
+    def _to_string(self, val):
+        if isinstance(val, GirType):
+            return val.glib_type_name
+        elif isinstance(val, ClassName):
+            return val.glib_type_name
+        else:
+            return str(val)