import os
import subprocess
from subprocess import CalledProcessError
from future.utils import raise_from
from data import Data as I
from data.decorators import data
from shutilwhich import which
from six.moves import shlex_quote
from tempdir import TempDir
from .exc import LatexBuildError
class LatexBuilder(object):
"""Base class for Latex builders."""
def build_pdf(self, source, texinputs=[]):
"""Generates a PDF from LaTeX a source.
If there are errors generating a ``LatexError`` is raised.
:param source: The LaTeX source.
:param texinputs: Include paths for TeX. An empty string causes the
default path to be added (see the tex manpage).
:returns: A :class:`~data.Data` instance containing the generated PDF.
"""
raise NotImplementedError
def is_available(self):
"""Checks if builder is available.
Builders that depend on external programs like ``latexmk`` can check
if these are found on the path or make sure other prerequisites are
met.
:return: A boolean indicating availability."""
raise NotImplementedError
class LatexMkBuilder(LatexBuilder):
"""A latexmk based builder for LaTeX files.
Uses the `latexmk
`_ script to
build latex files, which is part of some popular LaTeX distributions like
`texlive `_.
The build process consists of copying the source file to a temporary
directory and running latexmk on it, which will take care of reruns.
:param latexmk: The path to the ``latexmk`` binary (will be looked up on
``$PATH``).
:param pdflatex: The path to the ``pdflatex`` binary (will be looked up on
``$PATH``).
:param xelatex: The path to the ``xelatex`` binary (will be looked up on
``$PATH``).
:param variant: The LaTeX variant to use. Valid choices are
`pdflatex` and `xelatex`. Defaults to `pdflatex`.
"""
def __init__(self, latexmk='latexmk', pdflatex='pdflatex',
xelatex='xelatex', variant='pdflatex'):
self.latexmk = latexmk
self.pdflatex = pdflatex
self.xelatex = xelatex
self.variant = variant
@data('source')
def build_pdf(self, source, texinputs=[]):
with TempDir() as tmpdir,\
source.temp_saved(suffix='.latex', dir=tmpdir) as tmp:
# close temp file, so other processes can access it also on Windows
tmp.close()
base_fn = os.path.splitext(tmp.name)[0]
output_fn = base_fn + '.pdf'
latex_cmd = [shlex_quote(self.pdflatex),
'-interaction=batchmode',
'-halt-on-error',
'-no-shell-escape',
'-file-line-error',
'%O',
'%S', ]
if self.variant == 'pdflatex':
args = [self.latexmk,
'-pdf',
'-pdflatex={}'.format(' '.join(latex_cmd)),
tmp.name, ]
elif self.variant == 'xelatex':
args = [self.latexmk,
'-xelatex',
tmp.name, ]
else:
raise ValueError('Invalid LaTeX variant: {}'.format(
self.variant))
# create environment
newenv = os.environ.copy()
newenv['TEXINPUTS'] = os.pathsep.join(texinputs) + os.pathsep
try:
subprocess.check_call(args,
cwd=tmpdir,
env=newenv,
stdin=open(os.devnull, 'r'),
stdout=open(os.devnull, 'w'),
stderr=open(os.devnull, 'w'), )
except CalledProcessError as e:
raise_from(LatexBuildError(base_fn + '.log'), e)
return I(open(output_fn, 'rb').read(), encoding=None)
def is_available(self):
if not which(self.latexmk):
return False
if self.variant == 'pdflatex':
return bool(which(self.pdflatex))
if self.variant == 'xelatex':
return bool(which(self.xelatex))
class PdfLatexBuilder(LatexBuilder):
"""A simple pdflatex based buidler for LaTeX files.
Builds LaTeX files by copying them to a temporary directly and running
``pdflatex`` until the associated ``.aux`` file stops changing.
.. note:: This may miss changes if ``biblatex`` or other additional tools
are used. Usually, the :class:`~latex.build.LatexMkBuilder` will
give more reliable results.
:param pdflatex: The path to the ``pdflatex`` binary (will looked up on
``$PATH``).
:param max_runs: An integer providing an upper limit on the amount of times
``pdflatex`` can be rerun before an exception is thrown.
"""
def __init__(self, pdflatex='pdflatex', max_runs=15):
self.pdflatex = pdflatex
self.max_runs = 15
@data('source')
def build_pdf(self, source, texinputs=[]):
with TempDir() as tmpdir,\
source.temp_saved(suffix='.latex', dir=tmpdir) as tmp:
# close temp file, so other processes can access it also on Windows
tmp.close()
# calculate output filename
base_fn = os.path.splitext(tmp.name)[0]
output_fn = base_fn + '.pdf'
aux_fn = base_fn + '.aux'
args = [self.pdflatex, '-interaction=batchmode', '-halt-on-error',
'-no-shell-escape', '-file-line-error', tmp.name]
# create environment
newenv = os.environ.copy()
newenv['TEXINPUTS'] = os.pathsep.join(texinputs) + os.pathsep
# run until aux file settles
prev_aux = None
runs_left = self.max_runs
while runs_left:
try:
subprocess.check_call(args,
cwd=tmpdir,
env=newenv,
stdin=open(os.devnull, 'r'),
stdout=open(os.devnull, 'w'), )
except CalledProcessError as e:
raise_from(LatexBuildError(base_fn + '.log'), e)
# check aux-file
aux = open(aux_fn, 'rb').read()
if aux == prev_aux:
break
prev_aux = aux
runs_left -= 1
else:
raise RuntimeError(
'Maximum number of runs ({}) without a stable .aux file '
'reached.'.format(self.max_runs))
return I(open(output_fn, 'rb').read(), encoding=None)
def is_available(self):
return bool(which(self.pdflatex))
BUILDERS = {
'latexmk': LatexMkBuilder,
'pdflatex': PdfLatexBuilder,
'xelatexmk': lambda: LatexMkBuilder(variant='xelatex'),
}
PREFERRED_BUILDERS = ('latexmk', 'pdflatex', 'xelatexmk')
def build_pdf(source, texinputs=[], builder=None):
"""Builds a LaTeX source to PDF.
Will automatically instantiate an available builder (or raise a
:class:`exceptions.RuntimeError` if none are available) and build the
supplied source with it.
Parameters are passed on to the builder's
:meth:`~latex.build.LatexBuilder.build_pdf` function.
:param builder: Specify which builder should be used - ``latexmk``,
``pdflatex`` or ``xelatexmk``.
"""
if builder is None:
builders = PREFERRED_BUILDERS
elif builder not in BUILDERS:
raise RuntimeError('Invalid Builder specified')
else:
builders = (builder, )
for bld in builders:
bld_cls = BUILDERS[bld]
builder = bld_cls()
if not builder.is_available():
continue
return builder.build_pdf(source, texinputs)
else:
raise RuntimeError('No available builder could be instantiated. '
'Please make sure LaTeX is installed.')