resolves wireviz#320 read from stdin and write to stdout

src/wireviz/DataClasses.py

@@ -1,5 +1,5 @@
 # -*- coding: utf-8 -*-
-
+import sys
 from dataclasses import InitVar, dataclass, field
 from enum import Enum, auto
 from pathlib import Path
@@ -280,7 +280,7 @@ def __post_init__(self) -> None:
             self.gauge = g
 
             if self.gauge_unit is not None:
-                print(
+                sys.stderr.write(
                     f"Warning: Cable {self.name} gauge_unit={self.gauge_unit} is ignored because its gauge contains {u}"
                 )
             if u.upper() == "AWG":
@@ -304,7 +304,7 @@ def __post_init__(self) -> None:
                 )
             self.length = L
             if self.length_unit is not None:
-                print(
+                sys.stderr.write(
                     f"Warning: Cable {self.name} length_unit={self.length_unit} is ignored because its length contains {u}"
                 )
             self.length_unit = u

src/wireviz/Harness.py

@@ -1,11 +1,12 @@
 # -*- coding: utf-8 -*-
 
 import re
+import sys
 from collections import Counter
 from dataclasses import dataclass
 from itertools import zip_longest
 from pathlib import Path
-from typing import Any, List, Union
+from typing import Any, List, Union, Optional
 
 from graphviz import Graph
 
@@ -20,13 +21,12 @@
     Tweak,
     Side,
 )
-from wireviz.svgembed import embed_svg_images_file
+from wireviz.svgembed import embed_svg_images
 from wireviz.wv_bom import (
     HEADER_MPN,
     HEADER_PN,
     HEADER_SPN,
     bom_list,
-    component_table_entry,
     generate_bom,
     get_additional_component_table,
     pn_info_string,
@@ -543,11 +543,11 @@ def typecheck(name: str, value: Any, expect: type) -> None:
                                     f'( +)?{attr}=("[^"]*"|[^] ]*)(?(1)| *)', "", entry
                                 )
                                 if n_subs < 1:
-                                    print(
+                                    sys.stderr.write(
                                         f"Harness.create_graph() warning: {attr} not found in {keyword}!"
                                     )
                                 elif n_subs > 1:
-                                    print(
+                                    sys.stderr.write(
                                         f"Harness.create_graph() warning: {attr} removed {n_subs} times in {keyword}!"
                                     )
                                 continue
@@ -562,7 +562,7 @@ def typecheck(name: str, value: Any, expect: type) -> None:
                                 # If attr not found, then append it
                                 entry = re.sub(r"\]$", f" {attr}={value}]", entry)
                             elif n_subs > 1:
-                                print(
+                                sys.stderr.write(
                                     f"Harness.create_graph() warning: {attr} overridden {n_subs} times in {keyword}!"
                                 )
 
@@ -650,55 +650,58 @@ def svg(self):
         graph = self.graph
         return embed_svg_images(graph.pipe(format="svg").decode("utf-8"), Path.cwd())
 
-
     def output(
-        self,
-        filename: (str, Path),
-        view: bool = False,
-        cleanup: bool = True,
-        fmt: tuple = ("html", "png", "svg", "tsv"),
+            self,
+            output_dir: Optional[Union[str, Path]],
+            output_name: Optional[Union[str, Path]],
+            formats: List[str] | tuple[str]
     ) -> None:
         # graphical output
         graph = self.graph
-        svg_already_exists = Path(
-            f"{filename}.svg"
-        ).exists()  # if SVG already exists, do not delete later
-        # graphical output
-        for f in fmt:
-            if f in ("png", "svg", "html"):
-                if f == "html":  # if HTML format is specified,
-                    f = "svg"  # generate SVG for embedding into HTML
-                # SVG file will be renamed/deleted later
-                _filename = f"{filename}.tmp" if f == "svg" else filename
-                # TODO: prevent rendering SVG twice when both SVG and HTML are specified
-                graph.format = f
-                graph.render(filename=_filename, view=view, cleanup=cleanup)
-        # embed images into SVG output
-        if "svg" in fmt or "html" in fmt:
-            embed_svg_images_file(f"{filename}.tmp.svg")
-        # GraphViz output
-        if "gv" in fmt:
-            graph.save(filename=f"{filename}.gv")
-        # BOM output
-        bomlist = bom_list(self.bom())
-        if "tsv" in fmt:
-            open_file_write(f"{filename}.bom.tsv").write(tuplelist2tsv(bomlist))
-        if "csv" in fmt:
-            # TODO: implement CSV output (preferrably using CSV library)
-            print("CSV output is not yet supported")
-        # HTML output
-        if "html" in fmt:
-            generate_html_output(filename, bomlist, self.metadata, self.options)
-        # PDF output
-        if "pdf" in fmt:
+
+        if "csv" in formats:
+            # TODO: implement CSV output (preferably using CSV library)
+            sys.stderr.write("CSV output is not yet supported")
+        if "pdf" in formats:
             # TODO: implement PDF output
-            print("PDF output is not yet supported")
-        # delete SVG if not needed
-        if "html" in fmt and not "svg" in fmt:
-            # SVG file was just needed to generate HTML
-            Path(f"{filename}.tmp.svg").unlink()
-        elif "svg" in fmt:
-            Path(f"{filename}.tmp.svg").replace(f"{filename}.svg")
+            sys.stderr.write("PDF output is not yet supported")
+
+        outputs = {}
+        if "svg" in formats or "html" in formats:
+            # embed images into SVG output
+            outputs["svg"] = embed_svg_images(graph.pipe(format="svg", encoding="utf8"))
+
+        if "png" in formats:
+            outputs["png"] = graph.pipe(format="png")
+
+        # GraphViz output
+        if "gv" in formats:
+            outputs["gv"] = graph.pipe(format="gv")
+
+        if "tsv" in formats or "html" in formats:
+            bomlist = bom_list(self.bom())
+            # BOM output
+            if "tsv" in formats:
+                outputs["tsv"] = tuplelist2tsv(bomlist)
+
+            # HTML output
+            if "html" in formats and "svg" in outputs:
+                outputs["html"] = generate_html_output(outputs["svg"], output_dir, bomlist, self.metadata, self.options)
+
+        # print to stdout or write files in order
+        for f in formats:
+            if f in outputs:
+                output = outputs[f]
+                if output_dir is None or output_name is None:
+                    sys.stdout.write(output)
+                else:
+                    file = f"{output_dir}/{output_name}.{f}"
+                    if isinstance(output, (bytes, bytearray)):
+                        with open(file, "wb") as binary_file:
+                            binary_file.write(output)
+                    else:
+                        with open(file, "w") as binary_file:
+                            binary_file.write(output)
 
     def bom(self):
         if not self._bom:

src/wireviz/__init__.py

@@ -4,5 +4,5 @@
 __version__ = "0.4-dev"
 
 CMD_NAME = "wireviz"  # Lower case command and module name
-APP_NAME = "WireViz"  # Application name in texts meant to be human readable
-APP_URL = "https://github.com/formatc1702/WireViz"
+APP_NAME = "WireViz"  # Application name in texts meant to be human-readable
+APP_URL = "https://github.com/wireviz/WireViz"

src/wireviz/svgembed.py

@@ -38,15 +38,3 @@ def get_mime_subtype(filename: Union[str, Path]) -> str:
     if mime_subtype in mime_subtype_replacements:
         mime_subtype = mime_subtype_replacements[mime_subtype]
     return mime_subtype
-
-
-def embed_svg_images_file(
-    filename_in: Union[str, Path], overwrite: bool = True
-) -> None:
-    filename_in = Path(filename_in).resolve()
-    filename_out = filename_in.with_suffix(".b64.svg")
-    filename_out.write_text(
-        embed_svg_images(filename_in.read_text(), filename_in.parent)
-    )
-    if overwrite:
-        filename_out.replace(filename_in)

src/wireviz/wireviz.py

@@ -58,7 +58,7 @@ def parse(
         return_types (optional):
             One of the supported return types (see above), or a tuple of multiple return types.
             If set to None, no output is returned by the function.
-        output_formats (optional):
+        output_formats (Tuple[str], optional):
             One of the supported output types (see above), or a tuple of multiple output formats.
             If set to None, no files are generated.
         output_dir (Path | str, optional):
@@ -87,15 +87,18 @@ def parse(
 
     yaml_data, yaml_file = _get_yaml_data_and_path(inp)
     if output_formats:
-        # need to write data to file, determine output directory and filename
-        output_dir = _get_output_dir(yaml_file, output_dir)
-        output_name = _get_output_name(yaml_file, output_name)
-        output_file = output_dir / output_name
+        if str(output_dir) == "-":
+            # write to stdout
+            output_dir = None
+        else:
+            # write to directory
+            output_dir = _get_output_dir(yaml_file, output_dir)
+            output_name = _get_output_name(yaml_file, output_name)
 
     if yaml_file:
         # if reading from file, ensure that input file's parent directory is included in image_paths
         default_image_path = yaml_file.parent.resolve()
-        if not default_image_path in [Path(x).resolve() for x in image_paths]:
+        if default_image_path not in [Path(x).resolve() for x in image_paths]:
             image_paths.append(default_image_path)
 
     # define variables =========================================================
@@ -362,11 +365,11 @@ def alternate_type():  # flip between connector and cable/arrow
             harness.add_bom_item(line)
 
     if output_formats:
-        harness.output(filename=output_file, fmt=output_formats, view=False)
+        harness.output(formats=output_formats, output_dir=output_dir, output_name=output_name)
 
     if return_types:
         returns = []
-        if isinstance(return_types, str):  # only one return type speficied
+        if isinstance(return_types, str):  # only one return type specified
             return_types = [return_types]
 
         return_types = [t.lower() for t in return_types]
@@ -390,10 +393,11 @@ def _get_yaml_data_and_path(inp: Union[str, Path, Dict]) -> (Dict, Path):
             # if no FileNotFoundError exception happens, get file contents
             yaml_str = open_file_read(yaml_path).read()
         except (FileNotFoundError, OSError) as e:
-            # if inp is a long YAML string, Pathlib will raise OSError: [Errno 63]
+            # if inp is a long YAML string, Pathlib will raise OSError: [Errno 63].
             # when trying to expand and resolve it as a path.
-            # Catch this error, but raise any others
-            if type(e) is OSError and e.errno != 63:
+            # it can also raise OSError: [Errno 36] File name too long.
+            # Catch these errors, but raise any others.
+            if type(e) is OSError and e.errno != 63 and e.errno != 36:
                 raise e
             # file does not exist; assume inp is a YAML string
             yaml_str = inp
@@ -417,7 +421,7 @@ def _get_output_dir(input_file: Path, default_output_dir: Path) -> Path:
     return output_dir.resolve()
 
 
-def _get_output_name(input_file: Path, default_output_name: Path) -> str:
+def _get_output_name(input_file: Path, default_output_name: Union[None, str]) -> str:
     if default_output_name:  # user-specified output name
         output_name = default_output_name
     else:  # auto-determine appropriate output name
@@ -429,7 +433,7 @@ def _get_output_name(input_file: Path, default_output_name: Path) -> str:
 
 
 def main():
-    print("When running from the command line, please use wv_cli.py instead.")
+    sys.stderr.write("When running from the command line, please use wv_cli.py instead.")
 
 
 if __name__ == "__main__":