diff --git a/GoogleChart.cabal b/GoogleChart.cabal new file mode 100644 --- /dev/null +++ b/GoogleChart.cabal @@ -0,0 +1,15 @@ +Cabal-Version: >= 1.2 +Name: GoogleChart +Version: 0.1 +Synopsis: Generate web-based charts using the Google Chart API +Category: Graphics +License: BSD3 +License-File: LICENSE +Author: Evan Martin +Maintainer: martine@danga.com +Copyright: (c) 2008 Evan Martin +Homepage: http://neugierig.org/software/darcs/browse/?r=google-chart;a=summary + +Library + Build-Depends: base + Exposed-Modules: Graphics.Google.Chart diff --git a/Graphics/Google/Chart.hs b/Graphics/Google/Chart.hs new file mode 100644 --- /dev/null +++ b/Graphics/Google/Chart.hs @@ -0,0 +1,169 @@ +-- GoogleChart -- a Haskell module for using Google's Chart API +-- Copyright (c) 2008 Evan Martin + +{-| This module is for generating web-based charts using Google's Chart API: +. Its output is URLs that will resolve +to a PNG image of the resulting chart. + +Most of the functions in this module, with names like @setFoo@, take a 'Chart' +as an argument and produce a new 'Chart' with the specified attribute added. +These calls are designed to be chained together. See the example below. + +'Chart's are represented as a hierarchy of type classes so that parameters +that only affect a specific chart type are only available to that chart type. + +@ +putStrLn \"URL for your chart:\" +putStrLn $ 'chartURL' $ + 'setSize' 400 257 $ + 'setTitle' \"My Chart\" $ + 'setData' ('encodeDataSimple' [[1..20]]) $ + 'setLegend' [\"1 to 20\"] $ + 'newLineChart' +@ + +This produces: + + +-} + +module Graphics.Google.Chart ( + -- * Chart basics + -- | These functions and types are shared by all chart types. + Chart, + chartURL, + setSize, setTitle, setTitleOpts, setData, + -- ** Chart data + -- | There are multiple options for encoding chart data. See + -- for more details. + ChartData, encodeDataSimple, encodeDataText, encodeDataExtended, + + -- * Chart features + LegendChart, setLegend, + + -- * Specific chart types + -- ** Line charts + LineChart, newLineChart, + + -- ** Pie charts + PieChart, newPieChart, PieStyle(..), setLabels, + + -- ** Bar charts + BarChart, newBarChart, Orientation(..), BarStyle(..) +) where + +import Data.Char (chr, ord) +import Data.List (intercalate) +import Numeric (showHex) + +-- | Bar + +urlEnc str = concatMap enc str where + enc c | c >= 'A' && c <= 'Z' || c >= 'a' && c <= 'z' = [c] + | c >= '0' && c <= '9' = [c] + | c == '-' || c == '_' || c == '.' || c == '~' = [c] + | c == ' ' = "+" + | otherwise = '%':(showHex (ord c) "") + +-- All charts are internally represented as a list of (key,value) pairs. +-- We could switch this to Data.Map if it matters. +type Params = [(String,String)] + +-- |The type class underneath all Charts. +class Chart c where + params :: c -> Params + fromParams :: Params -> c + +setParam :: (Chart c) => String -> String -> c -> c +setParam key val c = fromParams $ (key,val) : filter ((/= key) . fst) (params c) + +-- |Set the width and height, in pixels, of the resulting image. +setSize :: (Chart c) => Int -> Int -> c -> c +setSize width height = setParam "chs" (show width ++ "x" ++ show height) + +-- |Set the title of the chart. +setTitle :: (Chart c) => String -> c -> c +setTitle title = setParam "chtt" title + +-- |Set options for the display of the title of the chart. +setTitleOpts :: (Chart c) => String -- ^Color of the text. + -> Int -- ^Size of the text. + -> c -> c +setTitleOpts color size = setParam "chts" (color ++ "," ++ show size) + +-- |Set the data displayed by the chart. +setData :: (Chart c) => ChartData -> c -> c +setData (ChartData str) = setParam "chd" str + +-- |Construct the URL used to show the chart. +chartURL :: (Chart c) => c -> String +chartURL chart = baseURL ++ intercalate "&" urlparams where + baseURL = "http://chart.apis.google.com/chart?" + urlparams = [urlEnc a ++ "=" ++ urlEnc b | (a,b) <- params chart] + +-- |All the encoding methods produce 'ChartData', which is usable by 'setData'. +newtype ChartData = ChartData String deriving Show + +-- |Encode data using the \"simple\" encoding. This produces minimal URLs but +-- doesn't have as much resolution. Input values must be in the range @0 <= x +-- <= 61@. Values outside the valid input range will be considered missing +-- data. +encodeDataSimple :: [[Int]] -> ChartData +encodeDataSimple datas = + ChartData $ "s:" ++ intercalate "," (map (map enc) datas) where + enc i | i >= 0 && i <= 25 = chr (ord 'A' + i) + | i >= 26 && i <= 51 = chr (ord 'a' + (i - 26)) + | i >= 52 && i <= 61 = chr (ord '0' + (i - 52)) + | otherwise = '_' + +-- |Encode data using the \"text\" encoding. XXX unimplemented. +encodeDataText :: [[Int]] -> ChartData +encodeDataText = undefined + +-- |Encode data using the \"extended\" encoding. XXX unimplemented. +encodeDataExtended :: [[Int]] -> ChartData +encodeDataExtended = undefined + +-- |LegendChart represents charts that can display legends with 'setLegend'. +class Chart c => LegendChart c where + -- |Set the legend for the corresponding data sets. The colors are taken + -- from the data set colors. + setLegend :: [String] -> c -> c + setLegend strs = setParam "chdl" (intercalate "|" strs) + +newtype LineChart = LineChart Params +instance Chart LineChart where + params (LineChart p) = p + fromParams = LineChart +instance LegendChart LineChart + +newLineChart :: LineChart +newLineChart = fromParams [("cht","lc")] + +newtype PieChart = PieChart Params +instance Chart PieChart where + params (PieChart p) = p + fromParams = PieChart +data PieStyle = Pie2D | Pie3D +newPieChart :: PieStyle -> PieChart +newPieChart Pie2D = fromParams [("cht","p")] +newPieChart Pie3D = fromParams [("cht","p3")] + +-- Specify missing values by passing an empty string. +setLabels :: [String] -> PieChart -> PieChart +setLabels labels = setParam "chl" $ intercalate "|" labels + +newtype BarChart = BarChart Params +instance Chart BarChart where + params (BarChart p) = p + fromParams = BarChart +instance LegendChart BarChart +data Orientation = Horizontal | Vertical +data BarStyle = Stacked | Grouped +newBarChart :: Orientation -> BarStyle -> BarChart +newBarChart orient style = + fromParams [("cht",'b':oLetter orient:sLetter style:[])] where + oLetter Horizontal = 'h' + oLetter Vertical = 'v' + sLetter Stacked = 's' + sLetter Grouped = 'g' diff --git a/LICENSE b/LICENSE new file mode 100644 --- /dev/null +++ b/LICENSE @@ -0,0 +1,26 @@ +Copyright (c) 2008 Evan Martin +All rights reserved. + +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are +met: +* Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. +* Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. +* Neither the name of the author nor the names of contributors may be + used to endorse or promote products derived from this software without + specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS +IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED +TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A +PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER +OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, +EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, +PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR +PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF +LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING +NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS +SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. diff --git a/Setup.lhs b/Setup.lhs new file mode 100644 --- /dev/null +++ b/Setup.lhs @@ -0,0 +1,4 @@ +#! /usr/bin/env runhaskell + +> import Distribution.Simple +> main = defaultMain