Internal method for processing placeholder requests

process_placeholder(ph, pptx, index, ..., error_call = current_env())

Arguments

ph: placeholder
pptx: A Powerpoint wrapped in a <pptx_container> object. see load_pptx()
index: Slide number
...: These dots are for future extensions and must be empty.
error_call: The execution environment of a currently running function, e.g. caller_env(). The function will be mentioned in error messages as the source of the error. See the call argument of abort() for more information.