--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/eric6/UI/Previewers/PreviewerHTML.py Sun Apr 14 15:09:21 2019 +0200
@@ -0,0 +1,750 @@
+# -*- coding: utf-8 -*-
+
+# Copyright (c) 2014 - 2019 Detlev Offenbach <detlev@die-offenbachs.de>
+#
+
+"""
+Module implementing a previewer widget for HTML, Markdown and ReST files.
+"""
+
+from __future__ import unicode_literals
+
+try: # Only for Py2
+ import StringIO as io # __IGNORE_EXCEPTION__
+ str = unicode
+except (ImportError, NameError):
+ import io # __IGNORE_WARNING__
+
+import os
+import threading
+import re
+import shutil
+import tempfile
+import sys
+
+from PyQt5.QtCore import pyqtSlot, pyqtSignal, Qt, QUrl, QSize, QThread
+from PyQt5.QtGui import QCursor
+from PyQt5.QtWidgets import QWidget, QVBoxLayout, QLabel, QCheckBox, \
+ QSizePolicy, QToolTip
+
+from E5Gui.E5Application import e5App
+
+import Utilities
+import Preferences
+
+
+class PreviewerHTML(QWidget):
+ """
+ Class implementing a previewer widget for HTML, Markdown and ReST files.
+ """
+ def __init__(self, parent=None):
+ """
+ Constructor
+
+ @param parent reference to the parent widget (QWidget)
+ """
+ super(PreviewerHTML, self).__init__(parent)
+
+ self.__layout = QVBoxLayout(self)
+
+ self.titleLabel = QLabel(self)
+ self.titleLabel.setWordWrap(True)
+ self.titleLabel.setTextInteractionFlags(Qt.NoTextInteraction)
+ self.__layout.addWidget(self.titleLabel)
+
+ self.__previewAvailable = True
+
+ try:
+ from PyQt5.QtWebEngineWidgets import QWebEngineView
+ self.previewView = QWebEngineView(self)
+ self.previewView.page().linkHovered.connect(self.__showLink)
+ self.__usesWebKit = False
+ except ImportError:
+ try:
+ from PyQt5.QtWebKitWidgets import QWebPage, QWebView
+ self.previewView = QWebView(self)
+ self.previewView.page().setLinkDelegationPolicy(
+ QWebPage.DelegateAllLinks)
+ self.__usesWebKit = True
+ except ImportError:
+ self.__previewAvailable = False
+ self.titleLabel.setText(self.tr(
+ "<b>HTML Preview is not available!<br/>"
+ "Install QtWebEngine or QtWebKit.</b>"))
+ self.titleLabel.setAlignment(Qt.AlignHCenter)
+ self.__layout.addStretch()
+ return
+
+ sizePolicy = QSizePolicy(QSizePolicy.Preferred, QSizePolicy.Expanding)
+ sizePolicy.setHorizontalStretch(0)
+ sizePolicy.setVerticalStretch(0)
+ sizePolicy.setHeightForWidth(
+ self.previewView.sizePolicy().hasHeightForWidth())
+ self.previewView.setSizePolicy(sizePolicy)
+ self.previewView.setContextMenuPolicy(Qt.NoContextMenu)
+ self.previewView.setUrl(QUrl("about:blank"))
+ self.__layout.addWidget(self.previewView)
+
+ self.jsCheckBox = QCheckBox(self.tr("Enable JavaScript"), self)
+ self.jsCheckBox.setToolTip(self.tr(
+ "Select to enable JavaScript for HTML previews"))
+ self.__layout.addWidget(self.jsCheckBox)
+
+ self.ssiCheckBox = QCheckBox(self.tr("Enable Server Side Includes"),
+ self)
+ self.ssiCheckBox.setToolTip(self.tr(
+ "Select to enable support for Server Side Includes"))
+ self.__layout.addWidget(self.ssiCheckBox)
+
+ self.jsCheckBox.clicked[bool].connect(self.on_jsCheckBox_clicked)
+ self.ssiCheckBox.clicked[bool].connect(self.on_ssiCheckBox_clicked)
+ self.previewView.titleChanged.connect(self.on_previewView_titleChanged)
+ if self.__usesWebKit:
+ self.previewView.linkClicked.connect(
+ self.on_previewView_linkClicked)
+
+ self.jsCheckBox.setChecked(
+ Preferences.getUI("ShowFilePreviewJS"))
+ self.ssiCheckBox.setChecked(
+ Preferences.getUI("ShowFilePreviewSSI"))
+
+ self.__scrollBarPositions = {}
+ self.__vScrollBarAtEnd = {}
+ self.__hScrollBarAtEnd = {}
+
+ self.__processingThread = PreviewProcessingThread()
+ self.__processingThread.htmlReady.connect(self.__setHtml)
+
+ self.__previewedPath = None
+ self.__previewedEditor = None
+
+ def shutdown(self):
+ """
+ Public method to perform shutdown actions.
+ """
+ if self.__previewAvailable:
+ self.__processingThread.wait()
+
+ @pyqtSlot(bool)
+ def on_jsCheckBox_clicked(self, checked):
+ """
+ Private slot to enable/disable JavaScript.
+
+ @param checked state of the checkbox (boolean)
+ """
+ Preferences.setUI("ShowFilePreviewJS", checked)
+ self.__setJavaScriptEnabled(checked)
+
+ def __setJavaScriptEnabled(self, enable):
+ """
+ Private method to enable/disable JavaScript.
+
+ @param enable flag indicating the enable state (boolean)
+ """
+ self.jsCheckBox.setChecked(enable)
+
+ settings = self.previewView.settings()
+ settings.setAttribute(settings.JavascriptEnabled, enable)
+
+ self.processEditor()
+
+ @pyqtSlot(bool)
+ def on_ssiCheckBox_clicked(self, checked):
+ """
+ Private slot to enable/disable SSI.
+
+ @param checked state of the checkbox (boolean)
+ """
+ Preferences.setUI("ShowFilePreviewSSI", checked)
+ self.processEditor()
+
+ @pyqtSlot(str)
+ def __showLink(self, urlStr):
+ """
+ Private slot to show the hovered link in a tooltip.
+
+ @param urlStr hovered URL
+ @type str
+ """
+ QToolTip.showText(QCursor.pos(), urlStr, self.previewView)
+
+ def processEditor(self, editor=None):
+ """
+ Public slot to process an editor's text.
+
+ @param editor editor to be processed (Editor)
+ """
+ if not self.__previewAvailable:
+ return
+
+ if editor is None:
+ editor = self.__previewedEditor
+ else:
+ self.__previewedEditor = editor
+
+ if editor is not None:
+ fn = editor.getFileName()
+
+ if fn:
+ extension = os.path.normcase(os.path.splitext(fn)[1][1:])
+ else:
+ extension = ""
+ if extension in \
+ Preferences.getEditor("PreviewHtmlFileNameExtensions") or \
+ editor.getLanguage() == "HTML":
+ language = "HTML"
+ elif extension in \
+ Preferences.getEditor("PreviewMarkdownFileNameExtensions") or \
+ editor.getLanguage().lower() == "markdown":
+ language = "Markdown"
+ elif extension in \
+ Preferences.getEditor("PreviewRestFileNameExtensions") or \
+ editor.getLanguage().lower() == "restructuredtext":
+ language = "ReST"
+ else:
+ self.__setHtml(fn, self.tr(
+ "<p>No preview available for this type of file.</p>"))
+ return
+
+ if fn:
+ project = e5App().getObject("Project")
+ if project.isProjectFile(fn):
+ rootPath = project.getProjectPath()
+ else:
+ rootPath = os.path.dirname(os.path.abspath(fn))
+ else:
+ rootPath = ""
+
+ if bool(editor.text()):
+ self.__processingThread.process(
+ fn, language, editor.text(),
+ self.ssiCheckBox.isChecked(), rootPath,
+ Preferences.getEditor("PreviewRestUseSphinx"),
+ Preferences.getEditor("PreviewMarkdownNLtoBR"),
+ Preferences.getEditor("PreviewMarkdownHTMLFormat"),
+ Preferences.getEditor("PreviewRestDocutilsHTMLFormat"))
+
+ def __setHtml(self, filePath, html, rootPath):
+ """
+ Private method to set the HTML to the view and restore the scroll bars
+ positions.
+
+ @param filePath file path of the previewed editor
+ @type str
+ @param html processed HTML text ready to be shown
+ @type str
+ @param rootPath path of the web site root
+ @type str
+ """
+ self.__previewedPath = Utilities.normcasepath(
+ Utilities.fromNativeSeparators(filePath))
+ self.__saveScrollBarPositions()
+ if self.__usesWebKit:
+ self.previewView.page().mainFrame().contentsSizeChanged.connect(
+ self.__restoreScrollBarPositions)
+ else:
+ self.previewView.page().loadFinished.connect(
+ self.__restoreScrollBarPositions)
+ if not filePath:
+ filePath = "/"
+ if rootPath:
+ baseUrl = QUrl.fromLocalFile(rootPath + "/index.html")
+ else:
+ baseUrl = QUrl.fromLocalFile(filePath)
+ self.previewView.setHtml(html, baseUrl=baseUrl)
+ if self.__previewedEditor:
+ self.__previewedEditor.setFocus()
+
+ @pyqtSlot(str)
+ def on_previewView_titleChanged(self, title):
+ """
+ Private slot to handle a change of the title.
+
+ @param title new title (string)
+ """
+ if title:
+ self.titleLabel.setText(self.tr("Preview - {0}").format(title))
+ else:
+ self.titleLabel.setText(self.tr("Preview"))
+
+ def __saveScrollBarPositions(self):
+ """
+ Private method to save scroll bar positions for a previewed editor.
+ """
+ if self.__usesWebKit:
+ frame = self.previewView.page().mainFrame()
+ if frame.contentsSize() == QSize(0, 0):
+ return # no valid data, nothing to save
+
+ pos = frame.scrollPosition()
+ self.__scrollBarPositions[self.__previewedPath] = pos
+ self.__hScrollBarAtEnd[self.__previewedPath] = \
+ frame.scrollBarMaximum(Qt.Horizontal) == pos.x()
+ self.__vScrollBarAtEnd[self.__previewedPath] = \
+ frame.scrollBarMaximum(Qt.Vertical) == pos.y()
+ else:
+ from PyQt5.QtCore import QPoint
+ try:
+ pos = self.previewView.scrollPosition()
+ except AttributeError:
+ pos = self.__execJavaScript(
+ "(function() {"
+ "var res = {"
+ " x: 0,"
+ " y: 0,"
+ "};"
+ "res.x = window.scrollX;"
+ "res.y = window.scrollY;"
+ "return res;"
+ "})()"
+ )
+ if pos is not None:
+ pos = QPoint(pos["x"], pos["y"])
+ else:
+ pos = QPoint(0, 0)
+ self.__scrollBarPositions[self.__previewedPath] = pos
+ self.__hScrollBarAtEnd[self.__previewedPath] = False
+ self.__vScrollBarAtEnd[self.__previewedPath] = False
+
+ def __restoreScrollBarPositions(self):
+ """
+ Private method to restore scroll bar positions for a previewed editor.
+ """
+ if self.__usesWebKit:
+ try:
+ self.previewView.page().mainFrame().contentsSizeChanged.\
+ disconnect(self.__restoreScrollBarPositions)
+ except TypeError:
+ # not connected, simply ignore it
+ pass
+
+ if self.__previewedPath not in self.__scrollBarPositions:
+ return
+
+ frame = self.previewView.page().mainFrame()
+ frame.setScrollPosition(
+ self.__scrollBarPositions[self.__previewedPath])
+
+ if self.__hScrollBarAtEnd[self.__previewedPath]:
+ frame.setScrollBarValue(
+ Qt.Horizontal, frame.scrollBarMaximum(Qt.Horizontal))
+
+ if self.__vScrollBarAtEnd[self.__previewedPath]:
+ frame.setScrollBarValue(
+ Qt.Vertical, frame.scrollBarMaximum(Qt.Vertical))
+ else:
+ if self.__previewedPath not in self.__scrollBarPositions:
+ return
+
+ pos = self.__scrollBarPositions[self.__previewedPath]
+ self.previewView.page().runJavaScript(
+ "window.scrollTo({0}, {1});".format(pos.x(), pos.y()))
+
+ @pyqtSlot(QUrl)
+ def on_previewView_linkClicked(self, url):
+ """
+ Private slot handling the clicking of a link.
+
+ @param url URL of the clicked link
+ @type QUrl
+ """
+ e5App().getObject("UserInterface").launchHelpViewer(url)
+
+ def __execJavaScript(self, script):
+ """
+ Private function to execute a JavaScript function Synchroneously.
+
+ @param script JavaScript script source to be executed
+ @type str
+ @return result of the script
+ @rtype depending upon script result
+ """
+ from PyQt5.QtCore import QEventLoop
+ loop = QEventLoop()
+ resultDict = {"res": None}
+
+ def resultCallback(res, resDict=resultDict):
+ if loop and loop.isRunning():
+ resDict["res"] = res
+ loop.quit()
+
+ self.previewView.page().runJavaScript(
+ script, resultCallback)
+
+ loop.exec_()
+ return resultDict["res"]
+
+
+class PreviewProcessingThread(QThread):
+ """
+ Class implementing a thread to process some text into HTML usable by the
+ previewer view.
+
+ @signal htmlReady(str, str, str) emitted with the file name, the processed
+ HTML and the web site root path to signal the availability of the
+ processed HTML
+ """
+ htmlReady = pyqtSignal(str, str, str)
+
+ def __init__(self, parent=None):
+ """
+ Constructor
+
+ @param parent reference to the parent object (QObject)
+ """
+ super(PreviewProcessingThread, self).__init__()
+
+ self.__lock = threading.Lock()
+
+ def process(self, filePath, language, text, ssiEnabled, rootPath,
+ useSphinx, convertNewLineToBreak, markdownHtmlFormat,
+ restDocutilsHtmlFormat):
+ """
+ Public method to convert the given text to HTML.
+
+ @param filePath file path of the text (string)
+ @param language language of the text (string)
+ @param text text to be processed (string)
+ @param ssiEnabled flag indicating to do some (limited) SSI processing
+ (boolean)
+ @param rootPath root path to be used for SSI processing (str)
+ @param useSphinx flag indicating to use Sphinx to generate the
+ ReST preview (boolean)
+ @param convertNewLineToBreak flag indicating to convert new lines
+ to HTML break (Markdown only) (boolean)
+ @param markdownHtmlFormat HTML format to be generated by markdown
+ (string)
+ @param restDocutilsHtmlFormat HTML format to be generated by docutils
+ (string)
+ """
+ with self.__lock:
+ self.__filePath = filePath
+ self.__language = language
+ self.__text = text
+ self.__ssiEnabled = ssiEnabled
+ self.__rootPath = rootPath
+ self.__haveData = True
+ self.__useSphinx = useSphinx
+ self.__convertNewLineToBreak = convertNewLineToBreak
+ self.__markdownHtmlFormat = markdownHtmlFormat
+ self.__restDocutilsHtmlFormat = restDocutilsHtmlFormat
+ if not self.isRunning():
+ self.start(QThread.LowPriority)
+
+ def run(self):
+ """
+ Public thread method to convert the stored data.
+ """
+ while True:
+ # exits with break
+ with self.__lock:
+ filePath = self.__filePath
+ language = self.__language
+ text = self.__text
+ ssiEnabled = self.__ssiEnabled
+ rootPath = self.__rootPath
+ useSphinx = self.__useSphinx
+ convertNewLineToBreak = self.__convertNewLineToBreak
+ markdownHtmlFormat = self.__markdownHtmlFormat
+ restDocutilsHtmlFormat = self.__restDocutilsHtmlFormat
+
+ self.__haveData = False
+
+ html = self.__getHtml(language, text, ssiEnabled, filePath,
+ rootPath, useSphinx, convertNewLineToBreak,
+ markdownHtmlFormat, restDocutilsHtmlFormat)
+
+ with self.__lock:
+ if not self.__haveData:
+ self.htmlReady.emit(filePath, html, rootPath)
+ break
+ # else - next iteration
+
+ def __getHtml(self, language, text, ssiEnabled, filePath, rootPath,
+ useSphinx, convertNewLineToBreak, markdownHtmlFormat,
+ restDocutilsHtmlFormat):
+ """
+ Private method to process the given text depending upon the given
+ language.
+
+ @param language language of the text (string)
+ @param text to be processed (string)
+ @param ssiEnabled flag indicating to do some (limited) SSI processing
+ (boolean)
+ @param filePath file path of the text (string)
+ @param rootPath root path to be used for SSI processing (str)
+ @param useSphinx flag indicating to use Sphinx to generate the
+ ReST preview (boolean)
+ @param convertNewLineToBreak flag indicating to convert new lines
+ to HTML break (Markdown only) (boolean)
+ @param markdownHtmlFormat HTML format to be generated by markdown
+ (string)
+ @param restDocutilsHtmlFormat HTML format to be generated by docutils
+ (string)
+ @return processed HTML text (string)
+ """
+ if language == "HTML":
+ if ssiEnabled:
+ html = self.__processSSI(text, filePath, rootPath)
+ else:
+ html = text
+ return self.__processRootPath(html, rootPath)
+ elif language == "Markdown":
+ return self.__convertMarkdown(text, convertNewLineToBreak,
+ markdownHtmlFormat)
+ elif language == "ReST":
+ return self.__convertReST(text, useSphinx, restDocutilsHtmlFormat)
+ else:
+ return self.tr(
+ "<p>No preview available for this type of file.</p>")
+
+ def __processSSI(self, txt, filename, root):
+ """
+ Private method to process the given text for SSI statements.
+
+ Note: Only a limited subset of SSI statements are supported.
+
+ @param txt text to be processed (string)
+ @param filename name of the file associated with the given text
+ (string)
+ @param root directory of the document root (string)
+ @return processed HTML (string)
+ """
+ if not filename:
+ return txt
+
+ # SSI include
+ incRe = re.compile(
+ r"""<!--#include[ \t]+(virtual|file)=[\"']([^\"']+)[\"']\s*-->""",
+ re.IGNORECASE)
+ baseDir = os.path.dirname(os.path.abspath(filename))
+ docRoot = root if root != "" else baseDir
+ while True:
+ incMatch = incRe.search(txt)
+ if incMatch is None:
+ break
+
+ if incMatch.group(1) == "virtual":
+ incFile = Utilities.normjoinpath(docRoot, incMatch.group(2))
+ elif incMatch.group(1) == "file":
+ incFile = Utilities.normjoinpath(baseDir, incMatch.group(2))
+ else:
+ incFile = ""
+ if os.path.exists(incFile):
+ try:
+ f = open(incFile, "r")
+ incTxt = f.read()
+ f.close()
+ except (IOError, OSError):
+ # remove SSI include
+ incTxt = ""
+ else:
+ # remove SSI include
+ incTxt = ""
+ txt = txt[:incMatch.start(0)] + incTxt + txt[incMatch.end(0):]
+
+ return txt
+
+ def __processRootPath(self, txt, root):
+ """
+ Private method to adjust absolute references to the given root path.
+
+ @param txt text to be processed
+ @type str
+ @param root directory of the document root
+ @type str
+ @return processed HTML
+ @rtype str
+ """
+ if not root:
+ return txt
+
+ root = Utilities.fromNativeSeparators(root)
+ if not root.endswith("/"):
+ root += "/"
+ rootLen = len(root)
+
+ refRe = re.compile(
+ r"""(href|src)=[\\"']/([^\\"']+)[\\"']""",
+ re.IGNORECASE)
+ pos = 0
+ while True:
+ refMatch = refRe.search(txt, pos)
+ if refMatch is None:
+ break
+
+ txt = (txt[:refMatch.start(0)] + refMatch.group(1) + '="' + root +
+ refMatch.group(2) + '"' + txt[refMatch.end(0):])
+ pos = refMatch.end(0) + rootLen
+
+ return txt
+
+ def __convertReST(self, text, useSphinx, restDocutilsHtmlFormat):
+ """
+ Private method to convert ReST text into HTML.
+
+ @param text text to be processed (string)
+ @param useSphinx flag indicating to use Sphinx to generate the
+ ReST preview (boolean)
+ @param restDocutilsHtmlFormat HTML format to be generated by docutils
+ (string)
+ @return processed HTML (string)
+ """
+ if useSphinx:
+ return self.__convertReSTSphinx(text)
+ else:
+ return self.__convertReSTDocutils(text, restDocutilsHtmlFormat)
+
+ def __convertReSTSphinx(self, text):
+ """
+ Private method to convert ReST text into HTML using 'sphinx'.
+
+ @param text text to be processed (string)
+ @return processed HTML (string)
+ """
+ try:
+ from sphinx.application import Sphinx # __IGNORE_EXCEPTION__
+ except ImportError:
+ return self.tr(
+ """<p>ReStructuredText preview requires the"""
+ """ <b>sphinx</b> package.<br/>Install it with"""
+ """ your package manager,'pip install Sphinx' or see"""
+ """ <a href="http://pypi.python.org/pypi/Sphinx">"""
+ """this page.</a></p>"""
+ """<p>Alternatively you may disable Sphinx usage"""
+ """ on the Editor, Filehandling configuration page.</p>""")
+
+ tempDir = tempfile.mkdtemp(prefix='eric-rest-')
+ try:
+ filename = 'sphinx_preview'
+ basePath = os.path.join(tempDir, filename)
+ fh = open(basePath + '.rst', 'w', encoding='utf-8')
+ fh.write(text)
+ fh.close()
+
+ overrides = {'html_add_permalinks': False,
+ 'html_copy_source': False,
+ 'html_title': 'Sphinx preview',
+ 'html_use_index': False,
+ 'html_use_modindex': False,
+ 'html_use_smartypants': True,
+ 'master_doc': filename}
+ app = Sphinx(srcdir=tempDir, confdir=None, outdir=tempDir,
+ doctreedir=tempDir, buildername='html',
+ confoverrides=overrides, status=None,
+ warning=io.StringIO())
+ app.build(force_all=True, filenames=None)
+
+ fh = open(basePath + '.html', 'r', encoding='utf-8')
+ html = fh.read()
+ fh.close()
+ finally:
+ shutil.rmtree(tempDir)
+
+ return html
+
+ def __convertReSTDocutils(self, text, htmlFormat):
+ """
+ Private method to convert ReST text into HTML using 'docutils'.
+
+ @param text text to be processed (string)
+ @param htmlFormat HTML format to be generated (string)
+ @return processed HTML (string)
+ """
+ if 'sphinx' in sys.modules:
+ # Make sure any Sphinx polution of docutils has been removed.
+ unloadKeys = [k for k in sys.modules.keys()
+ if k.startswith(('docutils', 'sphinx'))]
+ for key in unloadKeys:
+ sys.modules.pop(key)
+
+ try:
+ import docutils.core # __IGNORE_EXCEPTION__
+ import docutils.utils # __IGNORE_EXCEPTION__
+ except ImportError:
+ return self.tr(
+ """<p>ReStructuredText preview requires the"""
+ """ <b>python-docutils</b> package.<br/>Install it with"""
+ """ your package manager, 'pip install docutils' or see"""
+ """ <a href="http://pypi.python.org/pypi/docutils">"""
+ """this page.</a></p>""")
+
+ # redirect sys.stderr because we are not interested in it here
+ origStderr = sys.stderr
+ sys.stderr = io.StringIO()
+ try:
+ html = docutils.core.publish_string(
+ text, writer_name=htmlFormat.lower()).decode("utf-8")
+ except docutils.utils.SystemMessage as err:
+ errStr = str(err).split(":")[-1].replace("\n", "<br/>")
+ return self.tr(
+ """<p>Docutils returned an error:</p><p>{0}</p>"""
+ ).format(errStr)
+
+ sys.stderr = origStderr
+ return html
+
+ def __convertMarkdown(self, text, convertNewLineToBreak, htmlFormat):
+ """
+ Private method to convert Markdown text into HTML.
+
+ @param text text to be processed (string)
+ @param convertNewLineToBreak flag indicating to convert new lines
+ to HTML break (Markdown only) (boolean)
+ @param htmlFormat HTML format to be generated by markdown (string)
+ @return processed HTML (string)
+ """
+ try:
+ import markdown # __IGNORE_EXCEPTION__
+ except ImportError:
+ return self.tr(
+ """<p>Markdown preview requires the <b>Markdown</b> """
+ """package.<br/>Install it with your package manager,"""
+ """ 'pip install Markdown' or see """
+ """<a href="http://pythonhosted.org/Markdown/install.html">"""
+ """installation instructions.</a></p>""")
+
+ try:
+ import mdx_mathjax # __IGNORE_EXCEPTION__ __IGNORE_WARNING__
+ except ImportError:
+ # mathjax doesn't require import statement if installed
+ # as extension
+ pass
+
+ if convertNewLineToBreak:
+ extensions = ['fenced_code', 'nl2br', 'extra']
+ else:
+ extensions = ['fenced_code', 'extra']
+
+ # version 2.0 supports only extension names, not instances
+ if markdown.version_info[0] > 2 or \
+ (markdown.version_info[0] == 2 and
+ markdown.version_info[1] > 0):
+ class _StrikeThroughExtension(markdown.Extension):
+ """
+ Class is placed here, because it depends on imported markdown,
+ and markdown import is lazy.
+
+ (see https://pythonhosted.org/Markdown/extensions/api.html
+ this page for details)
+ """
+ DEL_RE = r'(~~)(.*?)~~'
+
+ def extendMarkdown(self, md, md_globals):
+ # Create the del pattern
+ del_tag = markdown.inlinepatterns.SimpleTagPattern(
+ self.DEL_RE, 'del')
+ # Insert del pattern into markdown parser
+ md.inlinePatterns.add('del', del_tag, '>not_strong')
+
+ extensions.append(_StrikeThroughExtension())
+
+ try:
+ return markdown.markdown(text, extensions=extensions + ['mathjax'],
+ output_format=htmlFormat.lower())
+ except (ImportError, ValueError):
+ # markdown raises ValueError or ImportError, depends on version
+ # It is not clear, how to distinguish missing mathjax from other
+ # errors. So keep going without mathjax.
+ return markdown.markdown(text, extensions=extensions,
+ output_format=htmlFormat.lower())
