Raise exceptions when failing. Closes #5

songbook.py

@@ -13,6 +13,7 @@ import sys
 
 from songbook.build import buildsongbook
 from songbook import __VERSION__
+from songbook import errors
 
 
 def argument_parser(args):
@@ -65,7 +66,13 @@ def main():
                                                )
     else:
         songbook['datadir'] = os.path.dirname(songbook_path)
-    buildsongbook(songbook, basename)
+    try:
+        buildsongbook(songbook, basename)
+    except errors.SongbookError as error:
+        print(error)
+        sys.exit(1)
+
+    sys.exit(0)
 
 if __name__ == '__main__':
     main()

songbook/build.py

@@ -11,10 +11,11 @@ import os.path
 import re
 import sys
 
+from songbook import __SHAREDIR__
+from songbook import errors
 from songbook.files import recursiveFind
 from songbook.index import processSXD
 from songbook.songs import Song, SongsList
-from songbook import __SHAREDIR__
 
 EOL = "\n"
 
@@ -95,9 +96,10 @@ def clean(basename):
             ]
 
     for ext in generated_extensions:
-        os.unlink(basename + ext)
-
-    return True
+        try:
+            os.unlink(basename + ext)
+        except Exception as exception:
+            raise errors.CleaningError(basename + ext, exception)
 
 
 def makeTexFile(sb, output):
@@ -243,7 +245,7 @@ def buildsongbook(sb, basename):
 
     # First pdflatex pass
     if call(["pdflatex", "--shell-escape", texFile]):
-        sys.exit(1)
+        raise errors.LatexCompilationError(basename)
 
     # Make index
     sxdFiles = glob.glob("%s_*.sxd" % basename)
@@ -256,8 +258,7 @@ def buildsongbook(sb, basename):
 
     # Second pdflatex pass
     if call(["pdflatex", "--shell-escape", texFile]):
-        sys.exit(1)
+        raise errors.LatexCompilationError(basename)
 
     # Cleaning
-    if not clean(basename):
-        sys.exit(1)
+    clean(basename)

songbook/errors.py

@@ -0,0 +1,26 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+
+"""Songbook exceptions and errors."""
+
+class SongbookError(Exception):
+    pass
+
+class LatexCompilationError(SongbookError):
+    """Error during LaTeX compilation."""
+
+    def __init__(self, basename):
+        self.basename = basename
+
+    def __str__(self):
+        return """Error while pdfLaTeX compilation of "{basename}.tex" (see {basename}.log for more information).""".format(basename = self.basename)
+
+class CleaningError(SongbookError):
+    """Error during cleaning of LaTeX auxiliary files."""
+
+    def __init__(self, filename, exception):
+        self.filename = filename
+        self.exception = exception
+
+    def __str__(self):
+        return """Error while removing "{filename}": {exception}.""".format(filename = self.filename, exception = str(self.exception))