require("chartdirector")
class RealtimesnapshotController < ApplicationController
def getchart()
#
# Data to draw the chart. In this demo, the data buffer will be filled by a random data
# generator. In real life, the data is probably stored in a buffer (eg. a database table, a
# text file, or some global memory) and updated by other means.
#
# We use a data buffer to emulate the last 240 samples.
sampleSize = 240
dataSeries1 = Array.new(sampleSize, 0)
dataSeries2 = Array.new(sampleSize, 0)
dataSeries3 = Array.new(sampleSize, 0)
timeStamps = Array.new(sampleSize, 0)
# Our pseudo random number generator
firstDate = Time.new - timeStamps.length
0.upto(timeStamps.length - 1) do |i|
timeStamps[i] = firstDate + i
p = timeStamps[i].to_i
dataSeries1[i] = Math.cos(p * 2.1) * 10 + 1 / (Math.cos(p) * Math.cos(p) + 0.01) + 20
dataSeries2[i] = 100 * Math.sin(p / 27.7) * Math.sin(p / 10.1) + 150
dataSeries3[i] = 100 * Math.cos(p / 6.7) * Math.cos(p / 11.9) + 150
end
# Create an XYChart object 600 x 320 pixels in size
c = ChartDirector::XYChart.new(600, 320)
# Set the plotarea at (55, 60) and of size 520 x 235 pixels with transparent background and
# border. Enable both horizontal and vertical grids by setting their colors to grey
# (cccccc). Set clipping mode to clip the data lines to the plot area.
c.setPlotArea(55, 60, 520, 235, -1, -1, ChartDirector::Transparent, 0xcccccc, 0xcccccc)
c.setClipping()
# Add a title to the chart using dark grey (0x333333) 20pt Arial Bold font
c.addTitle("Realtime Chart with Snapshot", "arialbd.ttf", 20, 0x333333)
# Add a legend box at the top of the plot area using horizontal layout. Use 10pt Arial Bold
# font, transparent background and border, and line style legend icon.
b = c.addLegend(55, 30, false, "arialbd.ttf", 10)
b.setBackground(ChartDirector::Transparent, ChartDirector::Transparent)
b.setLineStyleKey()
# Set the x and y axis stems to transparent and the label font to 10pt Arial
c.xAxis().setColors(ChartDirector::Transparent)
c.yAxis().setColors(ChartDirector::Transparent)
c.xAxis().setLabelStyle("arial.ttf", 10)
c.yAxis().setLabelStyle("arial.ttf", 10)
# Add y-axis title using 12pt Arial font
c.yAxis().setTitle("Y-Axis Title Placeholder", "arial.ttf", 12)
# For the automatic x and y axis labels, set the minimum spacing to 75 and 30 pixels.
c.xAxis().setTickDensity(75)
c.yAxis().setTickDensity(30)
# Set the x-axis label format
c.xAxis().setLabelFormat("{value|hh:nn:ss}")
# Create a line layer to plot the lines
layer = c.addLineLayer2()
# The x-coordinates are the timeStamps.
layer.setXData(timeStamps)
# The 3 data series are used to draw 3 lines. Here we put the latest data values as part of
# the data set name, so you can see them updated in the legend box.
layer.addDataSet(dataSeries1, 0xff0000, c.formatValue(dataSeries1[dataSeries1.length - 1],
"Alpha: {value|2}"))
layer.addDataSet(dataSeries2, 0x00cc00, c.formatValue(dataSeries2[dataSeries2.length - 1],
"Beta: {value|2}"))
layer.addDataSet(dataSeries3, 0x0000ff, c.formatValue(dataSeries3[dataSeries3.length - 1],
"Gamma: {value|2}"))
# Check if is download request
downloadFormat = params["download"]
if !((downloadFormat == nil) || (downloadFormat == ""))
fname = sprintf("demo_%s", c.formatValue(timeStamps[timeStamps.length - 1],
"yyyymmddhhnnss"))
if downloadFormat == "pdf"
# Output in PDF and stream as attachment
send_data(c.makeChart2(ChartDirector::PDF), :type => "application/pdf",
:disposition => "attachment", :filename => fname + ".pdf")
return
else
# Output in PNG and stream as attachment
send_data(c.makeChart2(ChartDirector::PNG), :type => "image/png",
:disposition => "attachment", :filename => fname + ".png")
return
end
end
# Output the chart
send_data(c.makeChart2(ChartDirector::PNG), :type => "image/png", :disposition => "inline")
end
end |
