R/Votes.getBillsByYearState.R

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

##' Get a list of bills according to year and state
##' 
##' This function is a wrapper for the Votes.getBillsByYearState() method of the PVS API Votes class which returns a list of bills that fit the year and state input. The function sends a request with this method to the PVS API for all years and state 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.getBillsByYearState(year, stateId, all=FALSE)
##' @param year a character string or list of character strings with the year(s)
##' @param stateId a character string or list of character strings with the state ID(s) (see references for details)
##' @param all a logical indicator; if TRUE data on all possible combinations of the stateId and year are returned, if FALSE (default) only the exact combinations (see example)
##' @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.\cr
##' See also: Matter U, Stutzer A (2015) pvsR: An Open Source Interface to Big Data on the American Political Sphere. PLoS ONE 10(7): e0130501. doi: 10.1371/journal.pone.0130501
##' @references http://api.votesmart.org/docs/Votes.html\cr
##' Use State.getStateIDs() to get a list of state IDs.\cr
##' See also: Matter U, Stutzer A (2015) pvsR: An Open Source Interface to Big Data on the American Political Sphere. PLoS ONE 10(7): e0130501. doi: 10.1371/journal.pone.0130501
##' @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 data frame of bills according to all year and state combinations
##' \dontrun{bills <- Votes.getBillsByYearState(year=list(2011,2012),
##' stateId=list("NY","NJ"), all=TRUE)}
##' \dontrun{head(bills)}
##' # get a data frame of bills according to the exact year and state combinations 
##' # (i.e., 2011/"NY", 2012/"NJ")
##' \dontrun{bills <- Votes.getBillsByYearState(year=list(2011,2012),
##' stateId=list("NY","NJ"), all=FALSE)}
##' \dontrun{head(bills)}
##' @export



Votes.getBillsByYearState <- 
	function (year, stateId, all=FALSE) {
		# internal function
		Votes.getBillsByYearState.basic <- 
			function (.year, .stateId) {
				
				request <-  "Votes.getBillsByYearState?"
				inputs  <-  paste("&year=",.year,"&stateId=",.stateId,sep="")
				output  <-  pvsRequest4(request,inputs)
				output$year <- .year
				output$stateId <- .stateId
				
				return(output)
			}
		
		if (all==TRUE) {
			
			# Main function  
			output.list <- lapply(year, FUN= function (y) {
				lapply(stateId, FUN= function (s) {
					Votes.getBillsByYearState.basic(.year=y, .stateId=s)
				}
				)
			}
			)
			
			
		} else {
			# Main function  
			reqdf <- data.frame(y=unlist(year), s=unlist(stateId))
			output.list <- lapply(1:dim(reqdf)[1], FUN= function (l) {
				Votes.getBillsByYearState.basic(.year=reqdf[l,"y"], .stateId=reqdf[l,"s"])
			})
		}  
		
		output.list <- redlist(output.list)
		output <- bind_rows(output.list)
		
		return(output)
	}