Newline woes when exporting to mediawiki markup

Newline woes when exporting to mediawiki markup

[Dov Grobgeld]

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Hello,

I've been trying to use the ox-mediawiki.el export option to export from
org mode to mediawiki mode.

Unfortunately the exporting does a poor job of exporting lists. E.g. the
following org mode source:

```
* A section
  - An item
  - Another item
    - A subitem
    - Another subitem
  - Back to first
```

is exported as:
```

= A section =
* An item

* Another item

  * A subitem

  * Another subitem

* Back to first

```
The expected is:
```
= A section =

* An item
* Another item
** A subitem
** Another subitem
* Back to first
```
I tried to modify ox-mediawiki.el to solve the following two issues:

- Get rid of redundant newlines between exported list items
- Replicate the leading asterisk to reflect the indentation level of the
list.

To get of the newline I tried to rewrite the org-export "item" translation
function `org-mw-item` but I would either get no newlines at all between my
items, or an extra newline between two subsequent items.

I just noted that ox-mediawiki is derived from the html backend, so perhaps
the limitations are there.

I would appreciate any guidance of how to fix this.

Thanks!

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Re: Newline woes when exporting to mediawiki markup

[Nicolas Goaziou]

Hello,

Dov Grobgeld <dov.grobgeld@gmail.com> writes:

> I tried to modify ox-mediawiki.el to solve the following two issues:
>
> - Get rid of redundant newlines between exported list items
> - Replicate the leading asterisk to reflect the indentation level of the
> list.
>
> To get of the newline I tried to rewrite the org-export "item" translation
> function `org-mw-item` but I would either get no newlines at all between my
> items, or an extra newline between two subsequent items.
>
> I just noted that ox-mediawiki is derived from the html backend, so perhaps
> the limitations are there.
>
> I would appreciate any guidance of how to fix this.

It's difficult to answer since I know neither what you tried nor what is
correct syntax, but I think asterisks could be obtained with

  (let ((level
         ;; Level can be seen as the number of parent plain lists.
         (length (org-element-map (org-element-lineage item) 'plain-list
                   #'identity info))))
    (make-string level ?*))

To remove any newline, you may try

  (org-element-put-property item :post-blank 0)

prior to returning.

Regards,
-- 
Nicolas Goaziou

Re: Newline woes when exporting to mediawiki markup

[Dov Grobgeld]

Thanks for the help. I now updated the function `org-mw-item` to:

    (defun org-mw-item (item contents info)
      "Transcode ITEM element into Mediawiki format.
    CONTENTS is the item contents.  INFO is a plist used as
    a communication channel."
      (let* ((type (org-element-property :type (org-export-get-parent item)))
             (bullet (if (eq type 'ordered) ?# ?*))
             (the-item (org-trim contents))
             (level (- (/
                     (length (org-element-map (org-element-lineage
item) 'plain-list
                              #'identity info)) 2) 3)))
        (progn
          (org-element-put-property item :post-blank 0)
          (format "%s %s" (make-string level bullet) the-item))))

With this change the following org input:
```
* A section
Here is a list of things

- An item
- Another item
    - A subitem
    - Another subitem
- Back to first
```

Is output as:
```
= A section =
Here is a list of things

* An item
* Another item

** A subitem
** Another subitem
* Back to first

```

This is close to the required result though there is still a redundant
empty line before "A subitem". How can  I get rid of it?

I also have no idea why I had to do the expression $level/2-3$ to get
the correct number of asterisks.

Another complication that I am currently ignoring is how to nest <UL>
and <OL> lists. But that's ok for now.

Thanks again!


On Tue, Jun 1, 2021 at 12:08 PM Nicolas Goaziou <mail@nicolasgoaziou.fr> wrote:
>
> Hello,
>
> Dov Grobgeld <dov.grobgeld@gmail.com> writes:
>
> > I tried to modify ox-mediawiki.el to solve the following two issues:
> >
> > - Get rid of redundant newlines between exported list items
> > - Replicate the leading asterisk to reflect the indentation level of the
> > list.
> >
> > To get of the newline I tried to rewrite the org-export "item" translation
> > function `org-mw-item` but I would either get no newlines at all between my
> > items, or an extra newline between two subsequent items.
> >
> > I just noted that ox-mediawiki is derived from the html backend, so perhaps
> > the limitations are there.
> >
> > I would appreciate any guidance of how to fix this.
>
> It's difficult to answer since I know neither what you tried nor what is
> correct syntax, but I think asterisks could be obtained with
>
>   (let ((level
>          ;; Level can be seen as the number of parent plain lists.
>          (length (org-element-map (org-element-lineage item) 'plain-list
>                    #'identity info))))
>     (make-string level ?*))
>
> To remove any newline, you may try
>
>   (org-element-put-property item :post-blank 0)
>
> prior to returning.
>
> Regards,
> --
> Nicolas Goaziou