Add support for xypic diagrams

We allow for xypic figures to be created with the same syntax as in
LaTeX, using the same approach as for Tikz diagrams. Indeed, we
implement this by tweaking the previous Tikz-specific API to handle
both cases.

script/src/tikz_diagrams/tikz_diagram.py → script/src/diagrams/diagram.py

@@ -1,6 +1,7 @@
 #!/usr/bin/python3.7
 
 import argparse
+import enum
 import errno
 import find_block
 import glob
@@ -15,7 +16,7 @@
 """
 Initialises logging. Logs to
 
-tikz_diagrams.log
+diagrams.log
 """
 logger = logging.getLogger(__name__)
 logger.setLevel(logging.INFO)
@@ -24,7 +25,7 @@
     "%(asctime)s %(levelname)s %(name)s %(message)s")
 log_directory = os.environ["NLAB_LOG_DIRECTORY"]
 logging_file_handler = logging.FileHandler(
-    os.path.join(log_directory, "tikz_diagrams.log"))
+    os.path.join(log_directory, "diagrams.log"))
 logging_file_handler.setFormatter(logging_formatter)
 logger.addHandler(logging_file_handler)
 
@@ -36,8 +37,12 @@ class SvgRenderingException(Exception):
     def __init__(self, message):
         super().__init__(message)
 
+class DiagramType(enum.Enum):
+    TIKZ = "tikz"
+    XYPIC = "xypic"
+
 def create_diagram_source_directory_if_needed():
-    diagram_source_directory = os.environ["NLAB_TIKZ_DIAGRAM_SOURCE_DIRECTORY"]
+    diagram_source_directory = os.environ["NLAB_DIAGRAM_SOURCE_DIRECTORY"]
     try:
         os.mkdir(diagram_source_directory)
     except OSError as osError:
@@ -75,24 +80,42 @@ def extract_error(output):
             break
     return "\n".join(error_description)
 
-def create_pdf(
-        diagram_source_directory,
-        diagram_id,
-        tikz_diagram,
-        is_commutative_diagram):
+def tikz_tex_source(diagram, is_commutative_diagram):
     tikz_diagram_template_path = os.environ["NLAB_TIKZ_DIAGRAM_TEMPLATE"]
     with open(tikz_diagram_template_path, "r") as tikz_diagram_template_file:
         tikz_diagram_template = tikz_diagram_template_file.read()
     if not is_commutative_diagram:
         libraries, tikz_diagram_without_tikz_libraries = extract_tikz_libraries(
-            tikz_diagram)
-        tex_source = string.Template(tikz_diagram_template).substitute(
+            diagram)
+        return string.Template(tikz_diagram_template).substitute(
             tikz_libraries = libraries,
             tikz_diagram = tikz_diagram_without_tikz_libraries)
     else:
-        tex_source = string.Template(tikz_diagram_template).substitute(
+        return string.Template(tikz_diagram_template).substitute(
             tikz_libraries = "\\usetikzlibrary{cd}",
-            tikz_diagram = tikz_diagram)
+            tikz_diagram = diagram)
+
+def xypic_tex_source(diagram):
+    xypic_diagram_template_path = os.environ["NLAB_XYPIC_DIAGRAM_TEMPLATE"]
+    with open(xypic_diagram_template_path, "r") as xypic_diagram_template_file:
+        xypic_diagram_template = xypic_diagram_template_file.read()
+        return string.Template(xypic_diagram_template).substitute(
+            xypic_diagram = diagram)
+
+def create_pdf(
+        diagram_source_directory,
+        diagram_id,
+        diagram,
+        diagram_type,
+	is_commutative_diagram = True):
+    if diagram_type == DiagramType.TIKZ:
+        tex_source = tikz_tex_source(diagram, is_commutative_diagram)
+    elif diagram_type == DiagramType.XYPIC:
+        tex_source = xypic_tex_source(diagram)
+    else:
+        raise ValueError(
+            "Following diagram type not handled: " +
+            diagram_type.value)
     tex_path = os.path.join(diagram_source_directory, diagram_id + ".tex")
     with open(tex_path, "w") as tex_source_file:
         tex_source_file.write(tex_source)
@@ -128,8 +151,15 @@ def remove_diagram_files(diagram_source_directory, diagram_id):
 def argument_parser():
     parser = argparse.ArgumentParser(
         description = (
-            "Creates SVG source from tikz diagram code passed into stdin"))
-    parser.add_argument(
+            "Creates SVG source from diagram code passed into stdin"))
+    subparsers = parser.add_subparsers(dest = "subcommand")
+    parser_tikz = subparsers.add_parser(
+        "tikz",
+        help = "Tikz diagrams")
+    parser_xypic = subparsers.add_parser(
+        "xypic",
+        help = "XYPic diagrams")
+    parser_tikz.add_argument(
         "-c",
         "--commutative_diagram",
         action = "store_true",
@@ -139,22 +169,30 @@ def argument_parser():
 def main():
     parser = argument_parser()
     arguments = parser.parse_args()
-    is_commutative_diagram = arguments.commutative_diagram
-    tikz_diagram = sys.stdin.read().strip()
+    diagram_type = DiagramType(arguments.subcommand)
+    diagram = sys.stdin.read().strip()
     diagram_source_directory = create_diagram_source_directory_if_needed()
     diagram_id = str(random.randint(10**8, (10**9) - 1))
     try:
-       create_pdf(
-           diagram_source_directory,
-           diagram_id,
-           tikz_diagram,
-           is_commutative_diagram)
-       svg_diagram = create_svg(diagram_source_directory, diagram_id)
+        if diagram_type == DiagramType.TIKZ:
+            create_pdf(
+                diagram_source_directory,
+                diagram_id,
+                diagram,
+                diagram_type,
+                arguments.commutative_diagram)
+        else:
+            create_pdf(
+                diagram_source_directory,
+                diagram_id,
+                diagram,
+                diagram_type)
+        svg_diagram = create_svg(diagram_source_directory, diagram_id)
     except PdfRenderingException as pdfRenderingException:
         message = (
             "An error occurred when running pdflatex on the following " +
             "diagram. \n" +
-            tikz_diagram +
+            diagram +
             "\nThe error was: " +
             str(pdfRenderingException))
         logger.warning(message)
@@ -163,17 +201,18 @@ def main():
         message = (
             "An error occurred when creating an SVG from a PDF for the " +
             "following diagram. \n" +
-            tikz_diagram)
+            diagram)
         logger.warning(
             message +
             "\nThe error was: " +
             str(svgRenderingException))
         sys.exit(message)
     except Exception as exception:
+        raise exception
         message = (
             "An unexpected error occurred when creating an SVG from a PDF " +
             "for the following diagram. \n" +
-            tikz_diagram)
+            diagram)
         logger.warning(
             message +
             "\nThe error was: " +
@@ -183,7 +222,7 @@ def main():
         remove_diagram_files(diagram_source_directory, diagram_id)
     logger.info(
         "Successfully created an SVG for the following diagram. \n" +
-        tikz_diagram)
+        diagram)
     print(svg_diagram)
 
 if __name__ == "__main__":

script/src/diagrams/xypic_diagram_template

@@ -0,0 +1,9 @@
+\documentclass[12pt]{standalone}
+
+\usepackage[all]{xy}
+
+\begin{document}
+
+$xypic_diagram
+
+\end{document}

script/src/renderer/renderer.py

@@ -26,6 +26,7 @@
 import theorem_environment_blocks
 import tikz_diagram_block
 import time
+import xypic_diagram_block
 
 """
 Initialises logging. Logs to
@@ -239,7 +240,8 @@ def _write_to_file_for_maruku(page_id, content_for_rendering):
 """
 def render(page_id, page_content):
     page_content = centre_block.handle_initial_centring(page_content)
-    page_content = tikz_diagram_block.handle_commutative_diagrams(page_content)
+    page_content = tikz_diagram_block.handle_tikz_diagrams(page_content)
+    page_content = xypic_diagram_block.handle_xypic_diagrams(page_content)
     pages_to_re_render_and_expire = []
     pages_to_render_to_include = []
     references_before_rendering = _references_before_rendering(page_id)
@@ -344,6 +346,8 @@ def initial_rendering(page_id, page_content):
         error_message = str(invalid_tex_exception)
     except tikz_diagram_block.TikzDiagramException as tikz_diagram_exception:
         error_message = str(tikz_diagram_exception)
+    except xypic_diagram_block.XyPicDiagramException as xypic_diagram_exception:
+        error_message = str(xypic_diagram_exception)
     except Exception as exception:
         error_message = "An unexpected error occurred when rendering the page"
         error = exception

script/src/renderer/tikz_diagram_block.py

@@ -17,9 +17,9 @@ def tikz_diagram_processor(tikz_diagram):
         "\\begin{tikzpicture}" +
         tikz_diagram +
         "\\end{tikzpicture}")
-    tikz_diagram_api_path = os.environ["NLAB_TIKZ_DIAGRAM_API_PATH"]
+    diagram_api_path = os.environ["NLAB_DIAGRAM_API_PATH"]
     completed_tikz_diagram_process = subprocess.run(
-        [ tikz_diagram_api_path ],
+        [ diagram_api_path, "tikz" ],
         input = tikz_diagram,
         text = True,
         capture_output = True)
@@ -40,9 +40,9 @@ def tikz_commutative_diagram_processor(tikz_diagram):
             "[row sep=huge, column sep=huge, transform shape, nodes = {scale=1.25}]" +
             tikz_diagram +
             "\\end{tikzcd}")
-    tikz_diagram_api_path = os.environ["NLAB_TIKZ_DIAGRAM_API_PATH"]
+    diagram_api_path = os.environ["NLAB_DIAGRAM_API_PATH"]
     completed_tikz_diagram_process = subprocess.run(
-        [ tikz_diagram_api_path, "-c" ],
+        [ diagram_api_path, "tikz", "-c" ],
         input = tikz_diagram,
         text = True,
         capture_output = True)
@@ -65,7 +65,7 @@ def define_tikz_commutative_diagram():
         tikz_commutative_diagram_processor,
         True)
 
-def handle_commutative_diagrams(content):
+def handle_tikz_diagrams(content):
     processor = find_block.Processor(
         [ define_tikz(), define_tikz_commutative_diagram() ])
     return processor.process(content)

script/src/renderer/xypic_diagram_block.py

@@ -0,0 +1,50 @@
+#!/usr/bin/python3
+
+"""
+For creating SVG code from a tikz diagram
+"""
+
+import find_block
+import os
+import subprocess
+
+class XyPicDiagramException(Exception):
+    def __init__(self, message):
+        super().__init__(message)
+
+def xypic_diagram_processor(xypic_diagram):
+    xypic_diagram = (
+        "\\xymatrix@" +
+        xypic_diagram +
+        "}")
+    diagram_api_path = os.environ["NLAB_DIAGRAM_API_PATH"]
+    completed_xypic_diagram_process = subprocess.run(
+        [ diagram_api_path, "xypic" ],
+        input = xypic_diagram,
+        text = True,
+        capture_output = True)
+    if completed_xypic_diagram_process.returncode != 0:
+        raise XyPicDiagramException(
+            completed_xypic_diagram_process.stderr)
+    return completed_xypic_diagram_process.stdout
+
+def define_xymatrix_default_size():
+    return find_block.Block(
+        "\\xymatrix{",
+        "}",
+        lambda diagram: xypic_diagram_processor(
+            "=5em{" + diagram),
+        True)
+
+def define_xymatrix():
+    return find_block.Block(
+        "\\xymatrix@",
+        "}",
+        xypic_diagram_processor,
+        True)
+
+def handle_xypic_diagrams(content):
+    processor = find_block.Processor(
+        [ define_xymatrix(), define_xymatrix_default_size() ])
+    return processor.process(content)
+