use mongodb to store the results.

Author: dzhuang

course/check.py

@@ -51,4 +51,4 @@ def latex2image_bin_check(app_configs, **kwargs):
         error = instance.check()
         if error:
             errors.append(error)
-    return errors
+    return errors

course/content.py

@@ -855,6 +855,7 @@ def expand_markup(
         repo,  # type: Repo_ish
         commit_sha,  # type: bytes
         text,  # type: Text
+        validate_only=False,  # type: bool
         use_jinja=True,  # type: bool
         jinja_env={},  # type: Dict
         ):
@@ -873,6 +874,46 @@ def expand_markup(
         template = env.from_string(text)
         text = template.render(**jinja_env)
 
+        # {{{ tex2img
+
+        from course.latex import tex_to_img_tag
+
+        def latex_not_enabled_warning(caller, *args, **kwargs):
+            return (
+                "<div class='alert alert-danger'>%s</div>" %
+                ("RELATE_LATEX_TO_IMAGE_ENABLED is set to False, "
+                 "no image will be generated."))
+
+        def jinja_tex_to_img_tag(caller, *args, **kwargs):
+            try:
+                return tex_to_img_tag(caller(), *args, **kwargs)
+            except Exception as e:
+                raise ValueError(
+                    u"<pre><div class='alert alert-danger'>"
+                    u"Error: %s: %s</div></pre>"
+                    % (type(e).__name__, str(e)))
+
+        template = env.from_string(text)
+        latex2image_enabled = getattr(
+            settings, "RELATE_LATEX_TO_IMAGE_ENABLED", False)
+
+        kwargs = {}
+        if jinja_env:
+            kwargs.update(jinja_env)
+
+        if latex2image_enabled:
+            env.globals["latex"] = jinja_tex_to_img_tag
+            text = template.render(**kwargs)
+        else:
+            if not validate_only:
+                env.globals["latex"] = latex_not_enabled_warning
+            else:
+                raise ImproperlyConfigured(
+                    _("RELATE_LATEX_TO_IMAGE_ENABLED is set to False, "
+                      "no image will be generated."))
+            text = template.render(**kwargs)
+        # }}}
+
     # }}}
 
     return text

course/latex/__init__.py

@@ -37,8 +37,16 @@
 TIKZ_PGF_RE = re.compile(r"\\begin\{(?:tikzpicture|pgfpicture)\}")
 DEFAULT_IMG_HTML_CLASS = "img-responsive"
 
+# {{{ mypy
+
+if False:
+    from typing import Text, Any, Optional  # noqa
+
+# }}}
+
 
 def tex_to_img_tag(tex_source, *args, **kwargs):
+    # type: (Text, *Any, **Any) -> Optional[Text]
     '''Convert LaTex to IMG tag'''
 
     compiler = kwargs.get("compiler", None)
@@ -49,8 +57,6 @@ def tex_to_img_tag(tex_source, *args, **kwargs):
     if not image_format:
         raise ValueError(_("'image_format' must be specified."))
 
-    output_dir = kwargs.get("output_dir")
-
     tex_filename = kwargs.get("tex_filename", None)
     tex_preamble = kwargs.get("tex_preamble", "")
     tex_preamble_extra = kwargs.get("tex_preamble_extra", "")
@@ -71,12 +77,13 @@ def tex_to_img_tag(tex_source, *args, **kwargs):
 
     if html_class_extra:
         if isinstance(html_class_extra, list):
-            html_class_extra = " ".join (html_class_extra)
+            html_class_extra = " ".join(html_class_extra)
         elif not isinstance(html_class_extra, six.string_types):
             raise ValueError(
                 _('"html_class_extra" must be a string or a list'))
-        html_class = "%s %s" %(DEFAULT_IMG_HTML_CLASS, html_class_extra)
-    else: html_class = DEFAULT_IMG_HTML_CLASS
+        html_class = "%s %s" % (DEFAULT_IMG_HTML_CLASS, html_class_extra)
+    else:
+        html_class = DEFAULT_IMG_HTML_CLASS
 
     texdoc = TexDoc(
         tex_source, preamble=tex_preamble,
@@ -88,22 +95,23 @@ def tex_to_img_tag(tex_source, *args, **kwargs):
 
     if (compiler == "latex"
         and image_format == "png"
-        and re.search(TIKZ_PGF_RE, tex_source)):
+        and
+            re.search(TIKZ_PGF_RE, tex_source)):
         image_format = "svg"
 
-    tex2img_class = get_tex2img_class(compiler, image_format)
+    assert isinstance(compiler, six.text_type)
+
+    tex2img_class = get_tex2img_class(compiler, image_format)  # type: ignore
 
     if not alt:
         alt = texdoc.document
 
     if alt:
-        from django.utils.html import escape
-        alt = "alt='%s'" % alt.strip().replace("\n","")
+        alt = "alt='%s'" % alt.strip().replace("\n", "")
 
     latex2img = tex2img_class(
         tex_source=texdoc.as_latex(),
         tex_filename=tex_filename,
-        output_dir=output_dir
         )
 
     return (