Add cachedir argument for export function

Use system-specific user cache directory thanks to appdirs

lokrez/export.py

@@ -1,5 +1,6 @@
 import os
 import subprocess
+import tempfile
 
 import jinja2
 
@@ -10,87 +11,95 @@ def generate_outfile(
         context,
         outfilename,
         log = None,
+        cachedir = None,
         ):
 
     # Template rendering
     # -------------------------------------------------------------------------
     log.info("Generating SVG using '{}' template".format(templatename))
 
+    log.debug(
+            "Initializing jinja2 with template dir '{}'" \
+                    .format(templatesdir)
+                    )
     jj2_env = jinja2.Environment(
-            loader = jinja2.FileSystemLoader( templatesdir )
+            loader = jinja2.FileSystemLoader(
+                str(templatesdir),
+                )
             )
 
     try:
         jj2_tpl = jj2_env.get_template(
-                os.path.join(
+                # Jinja specific path format
-                    templatename,
+                "{}/template.svg.j2".format(templatename),
-                    "template.svg.j2",
-                    )
                 )
-    except:
+    except Exception as e:
         log.error("Could not find template '{}'".format(templatename))
+        log.debug(e, exc_info=1)
         return None
 
-    extension = outfilename.split(".")[-1]
-
     # To SVG
     # -------------------------------------------------------------------------
-    if extension == "svg":
+    if outfilename.suffix == ".svg":
-        jj2_tpl.stream(context).dump( outfilename )
+        jj2_tpl.stream(context).dump( str(outfilename) )
         return outfilename
 
     # To PNG with inkscape
     # -------------------------------------------------------------------------
-    if extension == "png":
+    if outfilename.suffix == ".png":
 
-        try:
+        cachedir.mkdir(parents=True, exist_ok=True)
-            log.info("Exporting to {} using inkscape".format(extension))
-            import subprocess
 
-            jj2_tpl.stream(context).dump( "tmp.svg" )
+        with tempfile.NamedTemporaryFile(
-
+                suffix="svg",
-            inkscape_process = subprocess.Popen(
+                dir = str(cachedir),
-                    [
+                ) as tmpsvg:
-                        "inkscape",
-                        "tmp.svg",
-                        "--export-filename",
-                        outfilename,
-                        ],
-                    stdout = subprocess.PIPE,
-                    stderr = subprocess.STDOUT,
-                    universal_newlines = True,
-                    )
-
-            for line_out in iter(inkscape_process.stdout.readline, ""):
-                log.debug(line_out)
-
-            inkscape_process.stdout.close()
-
-            rv = inkscape_process.wait()
-
-            if rv != 0:
-                raise Exception(
-                        "Bad inkscape return code '{}'" \
-                                .format(inkscape_process.returncode)
-                                )
-
-            os.unlink("tmp.svg")
-
-            return outfilename
-
-        except Exception as e:
-            log.warning("Failed to export with inkscape")
             try:
-                os.unlink("tmp.svg")
+                log.info(
-            except:
+                        "Exporting to {} using inkscape" \
-                pass
+                                .format(outfilename.suffix),
-            log.debug(e)
+                                )
+                import subprocess
+
+                jj2_tpl.stream(context).dump( tmpsvg )
+
+                inkscape_process = subprocess.Popen(
+                        [
+                            "inkscape",
+                            tmpsvg.name,
+                            "--export-filename",
+                            str(outfilename),
+                            ],
+                        stdout = subprocess.PIPE,
+                        stderr = subprocess.STDOUT,
+                        universal_newlines = True,
+                        )
+
+                for line_out in iter(inkscape_process.stdout.readline, ""):
+                    log.debug(line_out)
+
+                inkscape_process.stdout.close()
+
+                rv = inkscape_process.wait()
+
+                if rv != 0:
+                    raise Exception(
+                            "Bad inkscape return code '{}'" \
+                                    .format(inkscape_process.returncode)
+                                    )
+
+
+                return outfilename
+
+            except Exception as e:
+                log.warning("Failed to export with inkscape")
+                log.debug(e)
 
     # To png, pdf or ps with cairosvg
     # -------------------------------------------------------------------------
-    if extension in [ "png", "pdf", "ps" ]:
+    if outfilename.suffix in [ ".png", ".pdf", ".ps" ]:
 
-        log.info("Exporting to {} using cairosvg".format(extension))
+        log.info("Exporting to {} using cairosvg".format(outfilename.suffix))
 
         try:
             import cairosvg
@@ -105,16 +114,16 @@ def generate_outfile(
 
         svg_str = jj2_tpl.render(context)
 
-        if extension == "png":
+        if outfilename.suffix == ".png":
             conversion_fun = cairosvg.svg2png
-        elif extension == "pdf":
+        elif outfilename.suffix == ".pdf":
             conversion_fun = cairosvg.svg2pdf
-        elif extension == "ps":
+        elif outfilename.suffix == ".ps":
             conversion_fun = cairosvg.svg2ps
 
         conversion_fun(
             bytestring = svg_str,
-            write_to = outfilename,
+            write_to = str(outfilename),
             )
 
         return outfilename
@@ -125,7 +134,7 @@ def generate_outfile(
             "Can't export to '{}' : unsupported format '{}'" \
                     .format(
                         outfilename,
-                        extension,
+                        outfilename.suffix,
                         )
                     )
     return None