JoeyGo23 · August 29, 2015 14:13 · May 2, 2012
diff --git a/image.gallery.R b/image.gallery.R
@@ -0,0 +1,31 @@
+image.gallery <- function(url, ncol = 3L) {
+
+## This function reformats the contents of a Craigslist search result URL
+## into an image gallery, opened into the default browser
+##
+## Inputs:
+##    - url:  a Craigslist search URL as created by search.url
+##    - ncol: the number of columns for the output image gallery
+##
+## Output: none. As a side effect, a browser is opened.
+
+   require(RCurl)
+   require(stringr)
+   require(R2HTML)
+
+   scrap     <- getURL(url)
+   adds      <- str_extract_all(scrap, '<p class="row">.*?</p>')[[1]]
+
+   pic.str   <- str_extract(adds, 'id="images:.*?jpg"')
+   pic.base  <- str_replace(pic.str, 'id="images:(.*jpg)"', "\\1")
+   pic.url   <- paste("http://images.craigslist.org/", pic.base, sep = "")
+   pic.tags  <- paste('<img src="', pic.url, '" alt="', pic.url, '" ',
+                      'style="width:100%"/>', sep = "")
+   adds      <- paste(pic.tags, '<BR>', adds)
+   add.mat   <- suppressWarnings(matrix(adds, ncol = ncol, byrow = TRUE))
+
+   html <- HTMLInitFile()
+   HTML(add.mat, innerBorder = 1, file = html)
+   HTMLEndFile(html)
+   browseURL(paste("file://", html, sep = ""))
+}
diff --git a/pick.category.R b/pick.category.R
@@ -0,0 +1,52 @@
+.pick.category <- function() {
+
+## This function prompts a menu for selecting a search category and returns
+## the corresponding 3-letter code used by Craigslist
+
+   categories <- read.table(textConnection("
+
+    CODE = DESCRIPTION
+
+    sss = all for sale / wanted
+    ata = antiques
+    ppa = appliances
+    ara = arts+crafts
+    pta = auto parts
+    baa = baby+kids
+    bar = barter
+    haa = beauty+health
+    bia = bikes
+    boo = boats
+    bka = books
+    bfa = business
+    cta = cars+trucks
+    ema = cd/dvd/vhs
+    moa = cell phones
+    cla = clothing+accessories
+    cba = collectibles
+    sya = computers
+    ela = electronics
+    gra = farm+garden
+    zip = free stuff
+    fua = furniture
+    gms = garage sales
+    foa = general for sale
+    hsa = household
+    wan = items wanted
+    jwa = jewelry
+    maa = materials
+    mca = motorcycles
+    msa = musical instruments
+    pha = photo+video
+    rva = recreational vehicles
+    sga = sporting goods
+    tia = tickets
+    tla = tools
+    taa = toys+games
+    vga = video gaming"), header = TRUE, sep = "=", strip.white = TRUE,
+                          stringsAsFactors = FALSE)
+
+   selected.idx <- menu(categories$DESCRIPTION, title = "pick a category:")
+
+   return(categories$CODE[selected.idx])
+}
diff --git a/search.craigslist.R b/search.craigslist.R
@@ -0,0 +1,35 @@
+search.craigslist <- function(site.url = "http://atlanta.craigslist.org",
+                              ncol     = 3L) {
+
+## This function prompts the user with questions for searching Craigslist
+## (search items, price, etc.) and displays the search results into an image
+## gallery.
+##
+## Inputs:
+##    - site.url: Craigslist site URL
+##    - ncol:     the number of columns for the output image gallery
+##
+## Output: none. As a side effect, a browser is opened.
+
+   query      <- readline("search Craigslist for: ")
+   category   <- .pick.category()
+   title.only <- readline("search titles only (press 1 or ENTER to skip): ")
+   min.price  <- readline("min price (press ENTER to skip): ")
+   max.price  <- readline("max price (press ENTER to skip): ")
+   pic.only   <- readline("pic only  (press 1 or ENTER to skip): ")
+
+   title.only <- title.only == "1"
+   min.price  <- as.integer(min.price)
+   max.price  <- as.integer(max.price)
+   pic.only   <- pic.only == "1"
+
+   url <- search.url(query      = query,
+                     site.url   = site.url,
+                     category   = category,
+                     title.only = title.only,
+                     min.price  = min.price,
+                     max.price  = max.price,
+                     pic.only   = pic.only)
+
+   image.gallery(url, ncol = ncol)
+}
diff --git a/search.url.R b/search.url.R
@@ -0,0 +1,37 @@
+search.url <- function(query,
+                       site.url   = "http://atlanta.craigslist.org",
+                       category   = "sss",
+                       title.only = TRUE,
+                       min.price  = integer(0),
+                       max.price  = integer(0),
+                       pic.only   = TRUE) {
+
+## This function creates a search URL on Craigslist.
+##
+## Inputs:
+##    - query:      search string
+##    - site.url:   Craigslist site URL
+##    - category:   a three-letter code for the category; some examples
+##                   "sss": all for sale/wanted, "zip": free stuff
+##    - title.only: boolean for restricting the search to add titles
+##    - min.price   minimum price
+##    - max.price:  maximum price
+##    - pic.only:   boolean for restricting the search to adds with pics
+##
+## Output: a string representing a Craigslist search URL
+
+   search <- list(query    = gsub(" ", "+", query),
+                  catAbb   = category,
+                  srchType = ifelse(title.only, "T", "A"),
+                  minAsk   = as.integer(min.price),
+                  maxAsk   = as.integer(max.price),
+                  hasPic   = as.numeric(pic.only))
+
+   valid <- sapply(search, length) > 0L
+
+   search.str  <- paste(names(search)[valid], search[valid],
+                        sep = "=", collapse = "&")
+   search.url  <- paste(site.url, "/search/sss?", search.str, sep = "")
+
+   return(search.url)
+}
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