R6 within S3 confusion

[dheimgartner]

Hi,

Thanks so much for this great package!

I would like to elaborate on one point that I find a little confusing and its consequence:

The confusion arises because of the following implementation:

• The main object generated with officer::read_docx() is of class S3
• However, within this S3 object lives a field that is R6 (namely the x$doc_obj)

Many of your functions directly act on this field (e.g. the officer::body_replace_all_text which thus directly modify the main object (reference semantics).

Here a simple example where template points to some local .docx file with the text replace_this appearing somewhere:

test <- officer::read_docx(template)
officer::body_replace_all_text(test, "replace_this", "with_that")
officer::docx_summary(test)

I am not that knowledgeable in OO but I don't expect S3 to have reference semantics. Maybe I am wrong in this point and one should expect this behaviour. Nevertheless, one thing that I find unlucky is that there is no obvious way to not change the original document. I.e.

test <- officer::read_docx(template)
test_copy <- test
officer::body_replace_all_text(test, "replace_this", "with_that")
officer::docx_summary(test_copy)

changes replace_this even in test_copy.

(My idea was to iterate over a .docx letter template and substitute addresses, names, etc.)

One solution would be to change the main object (in the above example the rdocx) to an R6. Then one could use the x$clone() to initialize a clone and modify the clone without sideeffects...

Would be happy to hear your thoughts!

Best,
Daniel

[davidgohel]

I agree this is not convenient.

This is something that could/should be improved. But I think everything should ideally use the S3 formalism or even simple R functions.

But for now, it's not really possible to clone/copy an 'officer' object.

Feel free to propose a PR to clone an object, but I think it's not a clear part in the code (undocumented R6), and it could be difficult :/

I can add a TODO for that feature, but I can't promise I will dedicate time to this soon (sorry again...).

[dheimgartner]

Hi David,

Thanks for your response!

I was mostly interested in your opinion and understand that it is not urgent on the task list.

I agree, S3 would be cleanest (and then one could simply copy the object). As for me, I found a work around which does not require copying an officer object.

Best
Daniel