How to convert a rtf string to plain text using R? - r

Question

I have lots of rtf strings (Base64) and I want to use R to obtain a plain text. Is it possible? There is one example bellow.
There are lots of ways using other languages, but it will be very useful if I found a "R way" to do the job.
rtfString <- "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"
plainText <- function(rtfString)
# The result will be something similar to this:
plainText
[1] "Sr. Presidente, Sras. e Srs. Parlamentares, ocupo esta tribuna para parabenizar a torcida paraense. O futebol paraense deu um show de civilidade neste final de semana, e a torcida bicolor do Papão da Curuzu, o Paysandu, está de parabéns, pois sagrou-se campeão do primeiro turno em cima do seu maior rival, vencendo o valoroso Clube do Remo.\nEstão de parabéns o Paysandu, o Governo do Estado, que deu um show de organização, a Justiça paraense, a polícia, os órgãos de segurança do Estado. Enfim, mais uma vez, parabéns à torcida bicolor.\nPaysandu, muitas e muitas glórias você ainda dará para essa sua brilhante torcida, que é a torcida bicolor de Belém do Pará.\nMuito obrigado, Sr. Presidente."

Answer 1

A combination of a few packages and some regex can accomplish this:
library(RCurl)
library(stringr)
library(magrittr)
decode_rtf <- function(txt) {
txt %>%
base64Decode %>%
str_replace_all("\\\\'e3", "ã") %>%
str_replace_all("\\\\'e1", "á") %>%
str_replace_all("\\\\'e9", "é") %>%
str_replace_all("\\\\'e7", "ç") %>%
str_replace_all("\\\\'ed", "í") %>%
str_replace_all("\\\\'f3", "ó") %>%
str_replace_all("\\\\'ea", "ê") %>%
str_replace_all("\\\\'e0", "à") %>%
str_replace_all("(\\\\[[:alnum:]']+|[\\r\\n]|^\\{|\\}$)", "") %>%
str_replace_all("\\{\\{[[:alnum:]; ]+\\}\\}", "") %>%
str_trim
}
rtfString <- "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"
decode_rtf(rtfString)
## [1] "O SR. DUDIMAR PAXIUBA (PSDB-PA. Sem revisão do orador.) - Sr. Presidente, Sras. e Srs. Parlamentares, ocupo esta tribuna para parabenizar a torcida paraense. O futebol paraense deu um show de civilidade neste final de semana, e a torcida bicolor do Papão da Curuzu, o Paysandu, está de parabéns, pois sagrou-se campeão do primeiro turno em cima do seu maior rival, vencendo o valoroso Clube do Remo. Estão de parabéns o Paysandu, o Governo do Estado, que deu um show de organização, a Justiça paraense, a polícia, os órgãos de segurança do Estado. Enfim, mais uma vez, parabéns à torcida bicolor. Paysandu, muitas e muitas glórias você ainda dará para essa sua brilhante torcida, que é a torcida bicolor de Belém do Pará. Muito obrigado, Sr. Presidente."
I'm sure there are some edge cases this might bork on but it's definitely a start for you.