org-element: headline's :title is sometimes string, sometimes list

org-element: headline's :title is sometimes string, sometimes list

[Hraban Luyat]

Hi all.

I'll let the code speak:

     (with-temp-buffer
       (org-mode)
       (insert "* Hello")
       (cl-flet ((say-type (prefix hl)
                   (message "Headline title from %s is of type: %s"
                            prefix
                            (type-of (org-element-property :title hl)))))
         (org-element-map (org-element-parse-buffer) 'headline
           (lambda (hl) (say-type "map" hl)))
         (goto-char (point-min))
         (say-type "context" (org-element-context))
         (say-type "at-point" (org-element-at-point))))

I expect: "string" everywhere.

I get:

     Headline title from map is of type: cons
     Headline title from context is of type: string
     Headline title from at-point is of type: string

Question 1: Do you know what that `cons' structure is? Where is it 
documented, how would I go about figuring this out myself? The 
org-element API documentation is daunting.

Question 2: how do I reliably get the title as a string? Properties are 
fine, I don't mind, but that weird list structure is awkward to handle.

Thank you

Hraban

Re: org-element: headline's :title is sometimes string, sometimes list

[Ihor Radchenko]

Hraban Luyat <hraban@0brg.net> writes:

> I expect: "string" everywhere.
>
> I get:
>
>      Headline title from map is of type: cons
>      Headline title from context is of type: string
>      Headline title from at-point is of type: string
>
> Question 1: Do you know what that `cons' structure is? Where is it 
> documented, how would I go about figuring this out myself? The 
> org-element API documentation is daunting.

This is "anonymous element". `org-element-parse-buffer', by default,
parses down to object level:

* Heading *bold* text

contains bold markup, which is reflected in the parsed AST. The title
itself is called secondary value, which may contain Org markup.

You are not getting it using `org-element-at-point' API because it does
not parse objects and simply returns a heading parsed down to element
level - :title is not parsed in details.

> Question 2: how do I reliably get the title as a string? Properties are 
> fine, I don't mind, but that weird list structure is awkward to handle.

Use `org-element-interpret-data' to convert Org AST back to plain text.

-- 
Ihor Radchenko // yantar92,
Org mode contributor,
Learn more about Org mode at <https://orgmode.org/>.
Support Org development at <https://liberapay.com/org-mode>,
or support my work at <https://liberapay.com/yantar92>

Re: org-element: headline's :title is sometimes string, sometimes list

[Hraban Luyat]

Thank you Ihor.

On 8/23/23 5:49 AM, Ihor Radchenko wrote:
> Hraban Luyat <hraban@0brg.net> writes:
>
>> I expect: "string" everywhere.
>>
>> I get:
>>
>>       Headline title from map is of type: cons
>>       Headline title from context is of type: string
>>       Headline title from at-point is of type: string
>>
>> Question 1: Do you know what that `cons' structure is? Where is it
>> documented, how would I go about figuring this out myself? The
>> org-element API documentation is daunting.
> This is "anonymous element". `org-element-parse-buffer', by default,
> parses down to object level:
>
> * Heading *bold* text
>
> contains bold markup, which is reflected in the parsed AST. The title
> itself is called secondary value, which may contain Org markup.
>
> You are not getting it using `org-element-at-point' API because it does
> not parse objects and simply returns a heading parsed down to element
> level - :title is not parsed in details.
>
>> Question 2: how do I reliably get the title as a string? Properties are
>> fine, I don't mind, but that weird list structure is awkward to handle.
> Use `org-element-interpret-data' to convert Org AST back to plain text.
>
> --
> Ihor Radchenko // yantar92,
> Org mode contributor,
> Learn more about Org mode at <https://orgmode.org/>.
> Support Org development at <https://liberapay.com/org-mode>,
> or support my work at <https://liberapay.com/yantar92>