How to create \alph footnotes, resetting by chapter where the chapter number is prepended to the footnote mark in the text below but not inline?

Question

I don't know if this package is required to make this happen.

\usepackage[bottom]{footmisc}

I reset the footnote counter on every chapter.

\makeatletter
\@addtoreset{footnote}{chapter}

I want to use "lower-case" alpha for my footnotes. This limits me to 26 per chapter, which should be sufficient...

\mainmatter
\renewcommand*{\thefootnote}{\alph{footnote}}

I want to prepend the chapter number in the footnotetext superscript, but not in the inline superscript.

Here is^a some text from^b chapter one.

Here^a is some text^b from chapter^c two.

Which in the footnotes below would render as...

^{1a} Text for footnote a in chapter one.
^{1b} Text for footnote b in chapter one.
^{2a} Text for footnote a in chapter two.
^{2b} Text for footnote b in chapter two.
^{2c} Text for footnote c in chapter two.

where the "chapter" counter is used for the prepend. I tried:

\renewcommand*{\thefootnote}{\thechapter\alph{footnote}}

but that prepends in the inline text and the footnote below. I only want it below.

This link suggests I can reformat the \renewcommand{\@makefntext}[1]{% ...

I have a two-column setup, and two chapters could appear on the same page. Ideally, I would like only the first element^a of each chapter to have the prepend, possibly with the chapter number in bold.

^{1a} Text for footnote a in chapter one.
^{b} Text for footnote b in chapter one.
^{2a} Text for footnote a in chapter two.
^{b} Text for footnote b in chapter two.
^{c} Text for footnote c in chapter two.

Answer 1

Check whether the footnote number is one or not.

\documentclass[oneside]{book}
\usepackage{scrextend}

\usepackage{lipsum} % for mock text

\deffootnote{2em}{0.5em}{\footnoteformatting}

\newcommand{\footnoteformatting}{%
  \makebox[0pt][r]{\textsuperscript{%
    \ifnum\value{footnote}=1
      \thechapter.%
    \fi
    \thefootnote
    \enspace
  }}%
}
\AtBeginDocument{\renewcommand{\thefootnote}{\alph{footnote}}}
\counterwithin{footnote}{chapter}

\setlength{\textheight}{0.5\textheight}

\begin{document}

\chapter{Test}

Text\footnote{First footnote} text\footnote{\lipsum[1][1-3]}

\chapter{Test}

Text\footnote{First footnote} text\footnote{Second footnote}

\end{document}

Answer 2

I used the following package:

\usepackage{scrextend}  
\deffootnote{2em}{0.5em}{{\footnoteformatting}} 

I hacked the formatting as follows (package allows string manipulation):

\usepackage{xstring}

\newcommand\footnoteformatting{%
    %\typeout{The footnote: \thefootnote}
    %\typeout{The footnote (value): \value{\thefootnote}}
    %\typeout{The footnote (arabic): \arabic{\thefootnote}}
    \IfInteger{\thefootnote}{%
        % no special formatting, it is an integer.
        \thefootnotemark.\enskip
        }{%
        % it is a \alph ...
        \StrLeft{\thefootnote}{1}[\firstchar]%
        \IfStrEq{\firstchar}{a}{%true
                {\color{black}\textbf{\thechapter}}\thefootnotemark.\enskip
            }{%false
                {\color{white}\textbf{\thechapter}}\thefootnotemark.\enskip
            }%

        }%
    }%

If the alpha string is {a} I place in black, otherwise white. I use the color code of "white" to hide the number. That allows for nice alignment of the footnote letters.

If I need to get passed {z} to {aa} using another footnote package, this logic will still work. An image showing footnote {h} from Chapter 1 and footnote {a} from Chapter 2.