library(tidyverse)
  library(htmltab)
  library(lubridate)
  
  election_graph <- function(pageURL) {
    election <- htmltab(pageURL,
                        which = 2,
                        rm_nodata_cols = F)
    election <- as.tibble(lapply(election, function(x) {gsub("unopp", "100", x)}))
    
    tidy_election <- gather(election, "Party", "Votes", 2:length(election))
    tidy_election$Year <- as.numeric(tidy_election$Year)
    tidy_election$Party <- factor(tidy_election$Party, levels = c("Conservative", "Labour", "Liberal", "Green", "SNP", "UKIP", "Other"))
    tidy_election$Votes <- as.numeric(tidy_election$Votes)
    
    election_victor <- tidy_election %>% filter(is.na(Votes) == FALSE) %>% group_by(Year) %>% summarize(Party = Party[which(Votes == max(Votes))])
    election_victor$Year <- as.numeric(election_victor$Year)
    election_victor$start_year <- election_victor$Year
    election_victor$end_year <- c(election_victor$Year[-1], ceiling(election_victor$Year[length(election_victor$Year)] + 1))
    election_victor[1,3] <- floor(election_victor[1,3] - 1)
    
    tidy_election$Votes <- as.numeric(sapply(tidy_election$Votes, function(x) {gsub(100, NA, x)}))
    
    party_colours <- c("#0087DC", "#DC241F", "#FAA61A", "#008066", "#FFF95D", "#EFE600", "dark grey")
    names(party_colours) <- c("Conservative", "Labour", "Liberal", "Green", "SNP", "UKIP", "Other")
    
    ggplot(tidy_election) +
      geom_rect(data = election_victor,
                aes(xmin = start_year,xmax = end_year, ymin = -Inf, ymax = Inf, fill = Party),
                alpha = 0.35,
                show.legend = F) +
      geom_line(aes(x = Year, y = Votes, colour = Party), size = 0.703) +
      geom_point(aes(x = Year, y = Votes, colour = Party)) +
      geom_hline(yintercept = 100, color="black", size = 1.5) +
      geom_vline(xintercept = 2019, color="black", size = 1.5) +
      scale_colour_manual(values = party_colours) +
      scale_fill_manual(values = party_colours) +
      theme(text = element_text(color="black", size = 14),
            axis.text = element_text(color="black", size = 11),
            axis.line.x = element_line(color="black", size = 0.703),
            axis.ticks.x = element_line(color="black", size = 0.703),
            axis.line.y = element_line(color="black", size = 0.703),
            axis.ticks.y = element_line(color="black", size = 0.703),
            axis.ticks.length = unit(5, "points"),
            panel.grid.major = element_line(color="blue", size = 0.5, linetype = 3),
            panel.grid.minor = element_blank(),
            panel.background = element_blank(),
            legend.position = c(.98, .97),
            legend.direction = "horizontal",
            legend.text = element_text(color="black", size = 11),
            legend.title=element_blank(),
            legend.justification = c("right", "top"),
            legend.box.just = "right",
            legend.key = element_blank(),
            legend.background = element_rect(fill = "white", colour = "black"),
            legend.margin = margin(0, 4, 4, 4)) +
      scale_x_continuous(expand = c(0, 0), limits = c(election_victor[[1,3]], election_victor$end_year[length(election_victor$end_year)]), breaks = seq(1890, 2010, 10)) +
      scale_y_continuous(expand = c(0, 0), limits = c(0, 100), breaks = seq(0, 100, 20)) +
      labs(x = "Year", y = "Percentage Vote")
  }
  
  election_graph("https://commons.wikimedia.org/wiki/File:BassetlawGraph.svg")
  
  ggsave("BassetlawGraph.svg", device = "svg", units = "cm", width = 20, height = 11, dpi = 120)