Render <latex> LaTeX elements using l2p command, and embed as images (used in epub)

diff --git a/librarian/latex.py b/librarian/latex.py
new file mode 100644 (file)
index 0000000..bfc2f7c
--- /dev/null
+++ b/librarian/latex.py
@@ -0,0 +1,70 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of Librarian, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+
+from os import path, system, popen2, unlink, rename
+from tempfile import NamedTemporaryFile
+import sys
+
+class LatexFragment(object):
+    def __init__(self, code, image_format='png', dirname="/tmp", resize=None):
+        self.code = code
+        self.temp = None
+        self.format = image_format
+        self.dirname = dirname
+        self.resize = resize
+        
+    def generate(self):
+        if self.temp is not None: 
+            return
+        self.temp = NamedTemporaryFile('r', 
+                                  suffix='.'+self.format, 
+                                  prefix=path.join(self.dirname,'librarian-latex-'),
+                                  delete=False)
+        try:
+            (processor, _out) = popen2("l2p -o '%(out)s' -d 1200" 
+                                     % {'out': self.temp.name},
+                                     "w")
+            
+            processor.write(isinstance(self.code, unicode) and \
+                            self.code.encode('utf-8') or\
+                            self.code)
+            print "LATEX: %s" % isinstance(self.code, unicode) and \
+                            self.code.encode('utf-8') or\
+                            self.code
+            processor.close()
+            _out.read() # waits for the process to finish
+
+            # Resize the image if needed
+            if self.resize:
+                n, e =  path.splitext(self.path)
+                aside_name = n + "_orig" + e
+                rename(self.path, aside_name)
+                system("convert -resize x%d %s %s" % (self.resize, aside_name, self.path))
+
+        except Exception as e:
+            import pdb; pdb.set_trace()
+            if path.exists(self.temp.name):
+                unlink(self.temp.name)
+            raise e
+
+    @property
+    def filename(self, splitext=False):
+        self.generate()
+        n = path.basename(self.temp.name)
+        if splitext: 
+            return path.splitext(n)
+        return n
+
+    @property
+    def path(self):
+        return path.join(self.dirname, self.filename)
+
+    def remove(self):
+        if self.temp:
+            unlink(self.temp.name)
+            self.temp = None
+
+    __del__ = remove

diff --git a/tests/test_latex.py b/tests/test_latex.py
new file mode 100644 (file)
index 0000000..22db615
--- /dev/null
+++ b/tests/test_latex.py
@@ -0,0 +1,19 @@
+# -*- coding: utf-8 -*-
+#
+# This file is part of Librarian, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+
+from nose.tools import *
+from librarian.latex import LatexFragment
+import os
+
+def test_latex_to_png():
+    lf = LatexFragment("$ \sum_{i = 0}^{123} n_i^{3}$")
+    name1 = lf.filename
+    assert_equal(name1.find("/"), -1)
+    name = lf.path
+    assert_true(os.path.exists(name))
+    print os.stat(name)
+    assert_true(os.stat(name).st_size > 0)
+    lf.remove()