ask.user.for.a.row: Asks the user for a row number from a data.frame table
Description
The function gets a data.frame and asks the user to choose
a row number. Once choosen, that row number is returned
from the function.
Usage
ask.user.for.a.row(TABLE,
header_text = "Possible versions to download (choose one)", questions_text)
Arguments
TABLE
a data.frame table with rows from which we
wish the user to choose a row. If TABLE is not a
data.frame, it will be coerced into one.
header_text
the text the users sees (often a
question) as a title for the printed table - explaining
which row he should choose from
questions_text
the question the users see after
the printing of the table - explaining which row he
should choose from. (the default is: "Please review the
table of versions from above, and enter the row number of
the file-version you'd like to install: ")
Value
The row number the user has choosen from the data.frame
table.
source
On how to ask the user for input:
http://stackoverflow.com/questions/5974967/what-is-the-correct-way-to-ask-for-user-input-in-an-r-program
Details
This function is used in installr when we are not
sure what version of the software to download, or when
various actions are available for the user to choose from.
If the user doesn't give a valid row number, the function
repeats its questions until a valid row number is chosen
(or the user escapes)
