Is there a way to use latex \cite{reference} in wordpress?

Question

I am using QuickLatex plugin and it works great. But when I tried to cite some references using \cite{paper1}, it did not seem work.

[latexpage]
Here is a citation \cite{example}.

\begin{thebibliography}

\bibitem{example}
Robert C. Merton, On the Pricing of Corporate Debt: The Risk Structure of Interest Rates. \textit{Journal of Finance} 1974; \textbf{2}:449–470.

\end{thebibliography}

Any help?

Answer 1

Outside of using other plugins, as mentioned in the comments, you would need to essentially parse the LaTeX yourself by filtering the_content.

Here is a very rough example of how you might capture and transform the post content to parse a bibliography. Please note that I don't know LaTeX, and this is just string parsing. Also, I'm tracking citations and references in the arrays $citations and $citation_refs in case that is useful to you, but it may not be.

#add_filter( 'the_content', 'my_latex_citation_filter' );

function my_latex_citation_filter( $content ) {
    $lines = explode( "\n", $content );

    $citation_refs = [];
    $citations     = [];
    $next_is_ref   = false;
    $next_ref      = '';
    $in_bib        = false;

    foreach ( $lines as $index => $line ) {
        preg_match( '/\\\cite\{([^}]+)\}/', $line, $matches );

        if ( ! empty( $matches[1] ) ) {
            $citation_refs[] = $matches[1];
            $next_ref        = "citation-{$matches[1]}";
            $lines[ $index ] = str_replace( $matches[0], sprintf( '<a href="#%1$s">%2$s</a>', $next_ref, $matches[1] ), $line );
        }

        if ( $next_is_ref && $next_ref ) {
            $lines[ $index ] = sprintf( '<span id="%s">' . $line . '</span>', $next_ref );
            $next_ref        = '';
            $next_is_ref     = false;
        }

        preg_match( '/\\\bibitem\{([^}]+)\}/', $line, $matches );

        if ( ! empty( $matches[1] ) ) {
            $citations[] = $matches[1];
            $next_is_ref = true;
            unset( $lines[ $index ] );
        }
    }

    return implode( "\n", $lines );
}


$content = '
[latexpage]
Here is a citation \cite{example}.

\begin{thebibliography}

\bibitem{example}
Robert C. Merton, On the Pricing of Corporate Debt: The Risk Structure of Interest Rates. \textit{Journal of Finance} 1974; \textbf{2}:449–470.

\end{thebibliography}
';

echo my_latex_citation_filter( $content );

Uncomment the line at the top (#add_filter...) and remove the last line echo ... to use this as a filter on the_content, but the code as-is above can be run inside of a standalone PHP file to see how it works. The output of the above is:

[latexpage]
Here is a citation <a href="#citation-example">example</a>.

\begin{thebibliography}

<span id="citation-example">Robert C. Merton, On the Pricing of Corporate Debt: The Risk Structure of Interest Rates. \textit{Journal of Finance} 1974; \textbf{2}:449–470.</span>

\end{thebibliography}