scientific-twocolumn-tables.py

"""
Pandoc filter using panflute: scientific 2column mode fixes
This filter does the following:
    1) fixes longtables -> tabular

It's intended use is for scientific papers that require 2 columns in the template layotu.
"""

from panflute import *

MAX_LBL_LENGTH = 20

def labelify(cap, type):
    maxlength = len(cap) if len(cap) < MAX_LBL_LENGTH else MAX_LBL_LENGTH
    return type + ':' + cap[0:maxlength].replace(' ', '_').replace('\\', '_')

def raw(txt):
    return RawBlock(txt, 'tex')

"""
    source MD:

blaaleft        blaricht
----------   -----------
iets                   9
nog iets              10

Table:  Demonstration of simple table syntax.

    without filter:

\begin{longtable}[]{@{}lr@{}}
\caption{Demonstration of simple table syntax.}\tabularnewline
\toprule
blaaleft & blaricht\tabularnewline
\midrule
\endfirsthead
\toprule
blaaleft & blaricht\tabularnewline
\midrule
\endhead
iets & 9\tabularnewline
nog iets & 10\tabularnewline
\bottomrule
\end{longtable}

    with filter:

\begin{table}[h!]
\centering
\caption{Demonstration of simple table syntax.\label{table:Demonstration_of_sim}}
\begin{tabular}{l r}
\hline
blaaleft & blaricht\\ [0.5ex]
\hline
\hline
iets & 9\tabularnewline
nog iets & 10\tabularnewline
\hline\end{tabular}
\end{table}
"""

def replace_longtables_with_tabular(elem, doc):
    # TODO still broken, & does not get passed on?
    def items():
        result = ''
        for row in elem.content:
            txt = ''
            for cell in row.content:
                txt +=  stringify(cell).replace('_', '\\_') + ' & '
            result += txt[0:-3] + '\\tabularnewline\n'
        return result

    def caption():
        cap = stringify(*elem.caption.content)
        return '\\caption{' + cap + '\\label{' + labelify(cap, 'table') + '}}\n'

    def tabular():
        aligns = {
            "AlignDefault": 'l',
            "AlignLeft": 'l',
            "AlignCenter": 'c',
            "AlignRight": 'r',
        }
        tab = '\\begin{tabular}{'
        for aligngroup in elem.colspec:
            # WHY? panflute 2 --  :param colspec: list of (alignment, colwidth) tuples; one for each column
            align = aligngroup[0]
            tab += aligns[align] + ' '
        return tab[0:-1] + '}\n'

    def headers():
        result = '\\hline\n'
        for cell in elem.head.content:
            result += stringify(cell) + ' & '
        return result[0:-3] + '\\\\ [0.5ex]\n\\hline\n\\hline\n'


    return [raw('\\begin{table}[h!]\n\\centering\n' +
            caption() +
            tabular() +
            headers() +
            items() + 
            '\\hline' + '\\end{tabular}\n\\end{table}')]


def prepare(doc):
    pass

def action(elem, doc):
    if doc.format != 'latex':
        return None

    if isinstance(elem, Table):
        return replace_longtables_with_tabular(elem, doc)

    return None

def finalize(doc):
    pass

# keep this structure: see http://scorreia.com/software/panflute/guide.html
# enabled filter using YAML config, panflute-filters=[x]
def main(doc=None):
    return run_filter(action,
                         prepare=prepare,
                         finalize=finalize,
                         doc=doc) 


if __name__ == '__main__':
    main()