| 1 | """LatexEquation Macro.""" |
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| 2 | import md5 |
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| 3 | import os |
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| 4 | import tempfile |
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| 5 | from trac.wiki.macros import WikiMacroBase |
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| 6 | |
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| 7 | # Include your favourite LaTeX preamble |
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| 8 | tex_preamble = r''' |
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| 9 | \documentclass{article} |
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| 10 | \usepackage{amsmath} |
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| 11 | \usepackage{amsthm} |
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| 12 | \usepackage{amssymb} |
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| 13 | \pagestyle{empty} |
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| 14 | \begin{document} |
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| 15 | \begin{equation*} |
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| 16 | ''' |
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| 17 | |
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| 18 | class LatexEquationMacro(WikiMacroBase): |
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| 19 | """Simple LatexEquation macro. |
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| 20 | |
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| 21 | Can be called with either `[[LatexEquation(E=Mc^x)]]` or |
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| 22 | {{{ |
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| 23 | {{{ |
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| 24 | #!LatexEquation |
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| 25 | E=Mc^2 |
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| 26 | }}} |
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| 27 | }}} |
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| 28 | This Macro: |
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| 29 | |
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| 30 | * Uses latex and dvipng executables to do it's work |
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| 31 | * Uses the the `\\begin{equation*}` latex environment |
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| 32 | * Caches the images in the `images/latex` subdir in the trac environment |
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| 33 | |
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| 34 | """ |
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| 35 | |
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| 36 | def expand_macro(self, formatter, name, text): |
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| 37 | """Return some output that will be displayed in the Wiki content. |
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| 38 | |
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| 39 | `name` is the actual name of the macro (no surprise, here it'll be |
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| 40 | `'LatexEquation'`), |
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| 41 | `text` is the text enclosed in parenthesis at the call of the macro. |
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| 42 | """ |
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| 43 | md5sum = md5.new(text).hexdigest() |
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| 44 | images_url = '../chrome/site/images/latex' |
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| 45 | images_folder = os.path.join(formatter.env.get_htdocs_dir(),"images") |
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| 46 | if not os.path.exists(images_folder): |
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| 47 | os.mkdir(images_folder) |
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| 48 | images_folder = os.path.join(images_folder, "latex") |
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| 49 | if not os.path.exists(images_folder): |
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| 50 | os.mkdir(images_folder) |
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| 51 | |
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| 52 | if not os.access('%s/%s.png' % (images_folder, md5sum), os.F_OK): |
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| 53 | cwd = os.getcwd() |
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| 54 | os.chdir("/tmp") |
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| 55 | fd, texfn = tempfile.mkstemp(suffix='.tex', prefix='eq') |
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| 56 | f = os.fdopen(fd, 'w+') |
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| 57 | f.write(tex_preamble) |
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| 58 | f.write(text) |
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| 59 | f.write(' \end{equation*}\end{document}') |
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| 60 | f.close() |
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| 61 | |
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| 62 | # compile LaTeX document. A DVI file is created |
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| 63 | ret = os.system('latex \\\\nonstopmode\\\\input{%s} >/dev/null 2>/dev/null' % texfn) |
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| 64 | tex_base = os.path.basename(texfn.replace('.tex', '')) |
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| 65 | tex_path = os.path.dirname(texfn) |
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| 66 | cmd = "dvipng -T tight -x 1200 -z 6 -bg Transparent " \ |
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| 67 | + "-o %s/%s.png %s 2>/dev/null 1>/dev/null" \ |
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| 68 | % (images_folder, md5sum, tex_base) |
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| 69 | ret = os.system(cmd) |
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| 70 | # lets clean up the crud a little |
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| 71 | ret = os.system('rm %s.*'%(tex_base,)) |
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| 72 | os.chdir(cwd) |
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| 73 | return '<img src="%s/%s.png" alt="%s" />' % (images_url, md5sum,text) |
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