R/Votes.getBillsByCategoryYearState.R

In umatter/pvsR: Interact with the Project Vote Smart API for Scientific Research

##' Get a list of bills according to category, year and state
##' 
##' This function is a wrapper for the Votes.getBillsByCategoryYearState() method of the PVS API Votes class which grabs a list of bills according to category, year and state. The function sends a request with this method to the PVS API for all years, state and category IDs given as a function input, extracts the XML values from the returned XML file(s) and returns them arranged in one data frame.
##' @usage Votes.getBillsByCategoryYearState(year, stateId, categoryId)
##' @param year a character string or list of character strings with the year ID(s)
##' @param stateId a character string or list of character strings with the state ID(s) (see references for details)
##' @param categoryId a character string or list of character strings with the category ID(s) (see references for details)
##' @return A data frame with a row for each bill and columns with the following variables describing the bill:\cr bills.bill*.billId,\cr bills.bill*.billNumber,\cr bills.bill*.title,\cr bills.bill*.type.
##' @references http://api.votesmart.org/docs/Votes.html\cr
##' Use State.getStateIDs() to get a list of state IDs.\cr
##' Use Votes.getCategories() or Rating.getCandidateRating() to get a list of category IDs.
##' @author Ulrich Matter <ulrich.matter-at-unibas.ch>
##' @examples
##' # First, make sure your personal PVS API key is saved as an option
##' # (options("pvs.key" = "yourkey")) or in the pvs.key variable:
##' \dontrun{pvs.key <- "yourkey"}
##' # get a list of bills in a certain category, year and state
##' \dontrun{bills <- Votes.getBillsByCategoryYearState(as.list(2010:2012),"NY",10)}
##' \dontrun{bills}
##' @export


Votes.getBillsByCategoryYearState <-
	function (year, stateId, categoryId) {
		# internal function
		Votes.getBillsByCategoryYearState.basic <- 
			function (.year, .stateId, .categoryId) {
				
				request <-  "Votes.getBillsByCategoryYearState?"
				inputs  <-  paste("&year=",.year,"&stateId=",.stateId, "&categoryId=", .categoryId, sep="")
				output  <-  pvsRequest(request,inputs)
				output$year <- .year
				output$stateId <- .stateId
				output$categoryId <- .categoryId
				return(output)
			}

		# Main function  
		output.list <- lapply(year, FUN= function (y) {
			lapply(stateId, FUN= function (s) {
				lapply(categoryId, FUN= function (c) {
					Votes.getBillsByCategoryYearState.basic(.year=y, .stateId=s, .categoryId=c)
				}
				)
			}
			)
		}
		)
		
		output.list <- redlist(output.list) 
		output <- bind_rows(output.list)
		
		return(output)
	}