Feedback appreciated.
----------
I will try to add more definitions after hearing what features are needed.
##Features
Markdown capabilities differ from environment to environment so I expect this will be only a base that one can modify so it fits his/her needs best.
- StackExchange MD supports only **H1-H3** headers and Sub/sub/Titles are cell styles which I've associated with them. Sub/sub/Sections are associated with **H4-H6** so you work more with those you may change it since the latter group will look here as ordinary text.
- An Output cells generated by `whatever // TraditionalForm` are automatically $\LaTeX$ blocks. An Inline `TraditionalForm` is inline $\LaTeX$.
- At the moment only this one type of **Output cell** is parsed.
- **Unknown cell styles** leave MD comment: `[//]: # (No rules defined for *CellStyleName*)`, which is not displayed ofc.
- I tried to convert **`Hyperlinks`** and it seems to work.
- Sub and Subsub `ItemsNumbered` only get prefix in form: `1., 2.` etc. I could put there what we see in MMA, like `1.2.1.` but it doesn't seem to be supported in MD. Or rather, it is sometimes but up to `SubitemNumbered` and no deeper.
----------
##Tests
I've put it as a procedure in palette which can convert things quite nicely.
This is a **test notebook** I'm using and the result of tests pasted here:
CreateDocument@ Uncompress@ "1:eJzNGE2MU0W4/Cw/qwtE0BhjdMSIu8vSbSsrWIK4P1QaF3bTV1gi4GbaTtsH782UefO2XdALxoMaEyOb8OfFYPyJmnggevNAwkHhYAx48oAmxkQPyknDQZxvXtvX1/d26QMOJrtvZr75/ub7m2/6RI5lil2RSMRaIT97mCA5xo4UFwNkqfyM65YoLmqsRolhOHs99dWLnNmVMSxwcYWHZImHZFFDQJbUhML2CNCWwZYuDIKcDUDVxKxBRlhNA6wcMwouTcY2iNUtJylGxRTRS2WhsEYkltbV4NWGv7quzGgZ0xLJ6iaxCGCAbjB+dC1vvL7jj+Fa/B81hjzCSlDZzon5TgFH1AU29HybXivr59AMTB1LpBWatqKFY8iznD39jglnuPz5HPWfRbvP4WzVmbevQwpLVWoMhFyavKRGl1wJ2ysnO6kgHAlpOVQmnESRA8hyXNCFzig2UoybSKcVW6Ai44jMYMPGsCWBCCOLVDDHgqC8ZIlyxGDVpHI5eKOz+PSGdIBzl6sIqilkBQBfZFhVwlx0Nx863l3qi5O0PH0JjqMB7oGF+SmcmvoOtMwPqe/G20iDiXaUO0wOeMjBHoODGni3zQ8qhdLgi5CRcHXH2SUQAZEXurvmS6FWKy9uAEAqKL+wYRU6xGqK4zyoCygKuEoFcIVwK8/1ioB8c4+aaPludJUAszQRrSAzgCITtujIDm4Mgqr8abZRWUBBJiqEdhaj3vN6k3aNqgzEPJhMxBJbsVWQf8q/AOzQUY3/3z85Xzwp1fv+yS/VODT97ak5Ob774Ben5/z1oqcuZVLmoIzbStkPCRkp2a2rSiD4la0zamwTuNwpSLqU0DoPKaT708uK+c2bS8onPc7wSltZryOquLhVJZyww9fnlBCkXVOjtwredey37/rvTxkXicTIbRBVsHfELLVl82hLEs2TOMcCEwfScUy3KgaehbVt4JB50DV/HgRcxB5s7aFIo5eo6qKMds3KsmDo9EgShXbJ4oadsrjUrK0QLSO2EE75UbLBBpOYEo0YJC8Y99m0LZaAKIUNi2gPy9n6KWYUOTZRRoYU5vnyAErTfHR9G5GKS26TgN5iIS6qwDeNMCzr5gxxjz42S7EpWxIFuB8sY3NOqNgnr1+iEmM3sy0yMUN4QNsyguURQAlv9VN0TZFtdCBE1m+T7Ma8pFNLl+tIAO+0iUtE0485q2FbMFP2A0HNU1OLBeV2N90W0A0o9SHM9mbGVQCVhagkBwer1Wq06tg1mmemItjDaHuH5PKGBnoBBm7wpmyqrjAnuIHBMKVMqJbHtaZmMKHDagGe3lMH5WNg48ylObOSKrAB2CBhCNPCwVg8gX1tGqlVOLEsCbiDnPpfXfHhLfM4FEdpld7+HJPVBXMCDWqaStsTsIDV3xf6BQL4MBaXDRZPyKvj7OUpNZ74bd0FGF/tefRrGPf/dX0ZNBX7d42ugvHi2nWH4aq5+Mu5IzC+FZ+qwu396/afq/5bPKBwevvMR+pbTt3U1ZGgGYf6LR29yM/szh3d6i9nHniRwE70Tm/kg99NmWCW5Kmf1Hj3LRjULuh69thmTj5jCj5ASA2/ufoVBc3eOMMqAV3QvW+7PjPe5CColrvJ741JVkea3VnTKgGwkHqev/IeA/2ufPDS0QDDrHEFuLYJAoYU+8OfhywQt/74j1bn5lngYak9EGm8rD0WCgaH1PbCjfeVcV5+ewMPMNJajwzXTvPAQwpPfhi1Qehjuz62Pb21fxL2re15wd7mfQusizatP29Bsdp0y/s2uV0t4uqLVCEZZYUO6nLbc+7vbU9V/U29dkNOxsbHd+6fnMhkZcUUSOrSW2/ExvUcx3wWjogMPQfjADI5wQYajjdm/bJb64P75Dh86sBMbDq2zbuOO2vYQdslfXMZl0sF7W8hA64OvI4IJhLczotRZlZ0g2x63q/kdN4gmO6t9DaVjfc51JwIm1PkMH9NPcgmOZNRY7o+9l+kUzotsCp0cN4MScMknhjakgbnbYnH2mh7mrT1DnG+VhpW+pmuekse0CECgndPN/69dSvA+ynOqNhJC/tkeyFvH20IVIxFn1G/Re3W85xZrCiQo5aFep/dvElmTx/qnZDtvsxd9NwASsTiQ31tvFVNgtZ0jBR1qm42SwPjyDW2DRGluf8A5XdXHg=="
(*^ double click to select. Don't evaluate this if the last edit was made by someone else than me*)
# Result
----------
# Title **bold**
## Subtitle *italic*
### Subsubtitle
Enter text here. Enter TraditionalForm input for evaluation in a separate cell below:
----------
Integrate[x, x] + Sqrt[x] // TraditionalForm
$$\frac{x^2}{2}+\sqrt{x}$$
+ Item
asdasd
ItemParagraph
+ Subitem
Text cell
[//]: # (No rules defined for DisplayFormula)
# Title with Hyperlink: [Wolfram Research, Inc.](http://www.wolfram.com) and
# a TraditionalForm expression: $\frac{x^2}{2}+\sqrt{x}$
# (*both are in InlineCells*)
Text with inline formula: $4$.
1. ItemNumbered
ItemParagraph
1. SubitemNumbered
SubitemParagraph
1. SubsubitemNumbered
SubsubitemParagraph
----------
fun[x_] := 1
[//]: # (No rules defined for Program)
----------
# /Result
## Code for palette
CreatePalette[#, CellContext -> Notebook] &@DynamicModule[{},
Button["Export to Markdown",
CreateDocument@exportMD@InputNotebook[]],
Initialization :> (
itemIndent = " ";
codeIndent = " ";
itemMark = "+ ";
itemPrefix = Function[{cellObj, style}, Module[{
ind, depth, numberedQ, paragraphQ},
ind = ToString@CurrentValue[cellObj, {"CounterValue", style}];
depth = StringCount[style, "sub", IgnoreCase -> True];
numberedQ =
StringCount[style, "numbered", IgnoreCase -> True] > 0;
paragraphQ =
StringCount[style, "paragraph", IgnoreCase -> True] > 0;
StringJoin@Flatten@{
ConstantArray[itemIndent, depth + If[paragraphQ, 2, 1]],
Which[
numberedQ, {ind, ". "},
paragraphQ, "",
True, itemMark]
}
]];
prefix[styleName_] := Switch[styleName,
"Title", "# ",
"Subtitle", "## ",
"Subsubtitle", "### ",
"Section", "#### ",
"Subsection", "##### ",
"Subsubsection", "###### ",
"Text", "",
"items", itemPrefix,
"code", codeIndent
];
styleWrapper[opts___] := Module[{italic, bold, wrapper
},
italic = MemberQ[{opts}, Verbatim[Rule][FontSlant, "Italic"]];
bold = MemberQ[{opts}, Verbatim[Rule][FontWeight, "Bold"]];
wrapper = Which[
bold, "**",
italic, "*",
True, ""
];
wrapper <> # <> wrapper &
];
parseCodeData[data_] := StringReplace[
First[FrontEndExecute[FrontEnd`ExportPacket[data, "InputText"]]],
"\n" -> "\n" <> codeIndent
];
textStyleQ = (StringCount[#, "title" | "section" | "text",
IgnoreCase -> True] > 0) &;
itemStyleQ = (StringCount[#, "item", IgnoreCase -> True] >
0) &;
codeStyleQ = MemberQ[{"Code", "Input"}, #] &;
exportMD[nb_NotebookObject] :=
StringJoin@Flatten[exportMD /@ Cells[nb]];
exportMD[cellObj_CellObject] :=
exportMD[NotebookRead[cellObj], cellObj];
exportMD[cell_Cell, cellObj_CellObject] :=
exportMD[#2, #, cellObj] & @@ cell;
exportMD[style_?textStyleQ, data_, cellObj_CellObject] := {
prefix[style], addPrefix[style] /@ Flatten@{parseData[data]},
"\n\n"
};
addPrefix[style_][expr : Except[_String]] := expr;
addPrefix[style_][s_String] :=
StringReplace[s, "\n" -> "\n" <> prefix[style]];
exportMD[style_?itemStyleQ, data_, cellObj_CellObject] := {
prefix["items"][cellObj, style], parseData@data, "\n\n"};
exportMD[style_?codeStyleQ, data_, cellObj_CellObject] := {
"\n\n----------\n\n",
codeIndent, parseCodeData@data,
"\n\n"};
exportMD["Output", BoxData[FormBox[boxes_, TraditionalForm]],
cellObj_CellObject] := TemplateApply[
"$$``$$\n\n", {boxesToTeX@boxes}
];
parseData[list_List] := parseData /@ list;
parseData[string_String] := string;
parseData[data_ (BoxData | TextData)] :=
List @@ (parseData /@ data);
parseData[cell_Cell] :=
parseData@First@cell; (*inlince cells style skipped*)
parseData[StyleBox[expr_, opts___]] :=
styleWrapper[opts]@parseData[expr];
parseData[
FormBox[boxes : Except[_TagBox], TraditionalForm, ___]] :=
Module[{teXForm},
teXForm = boxesToTeX@boxes;
"$" <> teXForm <> "$"
];
parseData[
box : ButtonBox[_, ___, BaseStyle -> "Hyperlink", ___]] :=
Module[{label, url},
{label, url} = {#, #2} & @@ ToExpression[box];
TemplateApply[
"[``](``)", {StringJoin@Flatten@{parseData@label}, url}]
];
(*default behaviour for boxes*)
parseData[boxes_] := parseData@First@boxes;
(*default behaviour for cell styles*)
exportMD[s_, ___] :=
TemplateApply["[//]: # (No rules defined for ``)\n\n", {s}];
boxesToTeX = ToString[ToExpression@#, TeXForm] &;
)
]
[1]: https://i.sstatic.net/4Lh8o.png