Merge ~richardw/jarmon/auto-apidocumentationv10.8pre1

 * Cleanup and add further doc strings for compatibility with yuidoc
 * Add a tool to automatically download and run yuidoc on the source tree
 * Add a tool to automatically create a releasable source archive containing apidocs
 * Add documentation of the apidoc and release tools.
 * Rearrange the source tree - moving all examples into the docs/examplesfolder

1 files changed, 954 insertions, 0 deletions

diff --git a/jarmon/jarmon.js b/jarmon/jarmon.js
new file mode 100644
index 0000000..44c4dad
--- /dev/null
+++ b/jarmon/jarmon.js
@@ -0,0 +1,954 @@
+/**
+ * Copyright (c) 2010 Richard Wall <richard (at) the-moon.net>
+ * See LICENSE for details.
+ *
+ * Wrappers and convenience fuctions for working with the javascriptRRD, jQuery,
+ * and Flot charting packages.
+ *
+ * Designed to work well with the RRD files generated by Collectd:
+ * - http://collectd.org/
+ *
+ * Requirements:
+ * - JavascriptRRD: http://javascriptrrd.sourceforge.net/
+ * - jQuery: http://jquery.com/
+ * - Flot: http://code.google.com/p/flot/
+ * - MochiKit.Async: http://www.mochikit.com/
+ *
+ * @module jarmon
+ */
+
+/**
+ * A namespace for Jarmon
+ *
+ * @class jarmon
+ * @static
+ */
+if(typeof jarmon == 'undefined') {
+    var jarmon = {};
+}
+
+jarmon.downloadBinary = function(url) {
+    /**
+     * Download a binary file asynchronously using the jQuery.ajax function
+     *
+     * @method downloadBinary
+     * @param url {String} The url of the object to be downloaded
+     * @return {Object} A deferred which will callback with an instance of javascriptrrd.BinaryFile
+     */
+
+    var d = new MochiKit.Async.Deferred();
+
+    $.ajax({
+        _deferredResult: d,
+        url: url,
+        dataType: 'text',
+        cache: false,
+        beforeSend: function(request) {
+            try {
+                request.overrideMimeType('text/plain; charset=x-user-defined');
+            } catch(e) {
+                // IE doesn't support overrideMimeType
+            }
+        },
+        success: function(data) {
+            try {
+                this._deferredResult.callback(new BinaryFile(data));
+            } catch(e) {
+                this._deferredResult.errback(e);
+            }
+        },
+        error: function(xhr, textStatus, errorThrown) {
+            // Special case for IE which handles binary data slightly
+            // differently.
+            if(textStatus == 'parsererror') {
+                if (typeof xhr.responseBody != 'undefined') {
+                    return this.success(xhr.responseBody);
+                }
+            }
+            this._deferredResult.errback(new Error(xhr.status));
+        }
+    });
+    return d;
+};
+
+
+jarmon.localTimeFormatter = function (v, axis) {
+    /**
+     * Copied from jquery.flot.js and modified to allow timezone
+     * adjustment.
+     *
+     * @method localTimeFormatter
+     * @param v {Number} The timestamp to be formatted
+     * @param axis {Object} A hash containing information about the time axis
+     * @return {String} The formatted datetime string
+     **/
+    // map of app. size of time units in milliseconds
+    var timeUnitSize = {
+        "second": 1000,
+        "minute": 60 * 1000,
+        "hour": 60 * 60 * 1000,
+        "day": 24 * 60 * 60 * 1000,
+        "month": 30 * 24 * 60 * 60 * 1000,
+        "year": 365.2425 * 24 * 60 * 60 * 1000
+    };
+
+    // Offset the input timestamp by the user defined amount
+    var d = new Date(v + axis.options.tzoffset);
+
+    // first check global format
+    if (axis.options.timeformat != null)
+        return $.plot.formatDate(d, axis.options.timeformat, axis.options.monthNames);
+
+    var t = axis.tickSize[0] * timeUnitSize[axis.tickSize[1]];
+    var span = axis.max - axis.min;
+    var suffix = (axis.options.twelveHourClock) ? " %p" : "";
+
+    if (t < timeUnitSize.minute)
+        fmt = "%h:%M:%S" + suffix;
+    else if (t < timeUnitSize.day) {
+        if (span < 2 * timeUnitSize.day)
+            fmt = "%h:%M" + suffix;
+        else
+            fmt = "%b %d %h:%M" + suffix;
+    }
+    else if (t < timeUnitSize.month)
+        fmt = "%b %d";
+    else if (t < timeUnitSize.year) {
+        if (span < timeUnitSize.year)
+            fmt = "%b";
+        else
+            fmt = "%b %y";
+    }
+    else
+        fmt = "%y";
+
+    return $.plot.formatDate(d, fmt, axis.options.monthNames);
+};
+
+
+/**
+ * A wrapper around an instance of javascriptrrd.RRDFile which provides a
+ * convenient way to query the RRDFile based on time range, RRD data source (DS)
+ * and RRD consolidation function (CF).
+ *
+ * @class jarmon.RrdQuery
+ * @constructor
+ * @param rrd {Object} A javascriptrrd.RRDFile
+ * @param unit {String} The unit symbol for this data series
+ **/
+jarmon.RrdQuery = function(rrd, unit) {
+    this.rrd = rrd;
+    this.unit = unit;
+};
+
+jarmon.RrdQuery.prototype.getData = function(startTime, endTime, dsId, cfName) {
+    /**
+     * Generate a Flot compatible data object containing rows between start and
+     * end time. The rows are taken from the first RRA whose data spans the
+     * requested time range.
+     *
+     * @method getData
+     * @param startTime {Number} start timestamp
+     * @param endTime {Number} end timestamp
+     * @param dsId {Variant} identifier of the RRD datasource (string or number)
+     * @param cfName {String} The name of an RRD consolidation function (CF)
+     *      eg AVERAGE, MIN, MAX
+     * @return {Object} A Flot compatible data series
+     *      eg label: '', data: [], unit: ''
+     **/
+    var startTimestamp = startTime/1000;
+
+    var lastUpdated = this.rrd.getLastUpdate();
+    var endTimestamp = lastUpdated;
+    if(endTime) {
+        endTimestamp = endTime/1000;
+        // If end time stamp is beyond the range of this rrd then reset it
+        if(lastUpdated < endTimestamp) {
+            endTimestamp = lastUpdated;
+        }
+    }
+
+    if(dsId == null) {
+        dsId = 0;
+    }
+    var ds = this.rrd.getDS(dsId);
+
+    if(cfName == null) {
+        cfName = 'AVERAGE';
+    }
+
+    var rra, step, rraRowCount, firstUpdated;
+
+    for(var i=0; i<this.rrd.getNrRRAs(); i++) {
+        // Look through all RRAs looking for the most suitable
+        // data resolution.
+        rra = this.rrd.getRRA(i);
+
+        // If this rra doesn't use the requested CF then move on to the next.
+        if(rra.getCFName() != cfName) {
+            continue;
+        }
+
+        step = rra.getStep();
+        rraRowCount = rra.getNrRows();
+        firstUpdated = lastUpdated - (rraRowCount - 1) * step;
+        // We assume that the RRAs are listed in ascending order of time range,
+        // therefore the first RRA which contains the range minimum should give
+        // the highest resolution data for this range.
+        if(firstUpdated <= startTimestamp) {
+            break;
+        }
+    }
+    // If we got to the end of the loop without ever defining step, it means
+    // that the CF check never succeded.
+    if(!step) {
+        throw new Error('Unrecognised consolidation function: ' + cfName);
+    }
+
+    var startRow = rraRowCount - parseInt((lastUpdated - Math.max(startTimestamp, firstUpdated))/step) - 1;
+    var endRow = rraRowCount - parseInt((lastUpdated - endTimestamp)/step) - 1;
+
+    var flotData = [];
+    var timestamp = firstUpdated + (startRow - 1) * step;
+    var dsIndex = ds.getIdx();
+    for (var i=startRow; i<=endRow; i++) {
+        flotData.push([timestamp*1000.0, rra.getEl(i, dsIndex)]);
+        timestamp += step;
+    }
+
+    // Now get the date of the earliest record in entire rrd file, ie that of
+    // the last (longest range) rra.
+    rra = this.rrd.getRRA(this.rrd.getNrRRAs()-1);
+    firstUpdated = lastUpdated - (rra.getNrRows() -1) * rra.getStep();
+
+    return {'label': ds.getName(), 'data': flotData, 'unit': this.unit,
+            'firstUpdated': firstUpdated*1000.0,
+            'lastUpdated': lastUpdated*1000.0};
+};
+
+/**
+ * A wrapper around RrdQuery which provides asynchronous access to the data in a
+ * remote RRD file.
+ *
+ * @class jarmon.RrdQueryRemote
+ * @constructor
+ * @param url {String} The url of a remote RRD file
+ * @param unit {String} The unit suffix of this data eg 'bit/sec'
+ * @param downloader {Function} A callable which returns a Deferred and calls
+ *      back with a javascriptrrd.BinaryFile when it has downloaded.
+ **/
+jarmon.RrdQueryRemote = function(url, unit, downloader) {
+    this.url = url;
+    this.unit = unit;
+    this.downloader = downloader;
+    this.lastUpdate = 0;
+    this._download = null;
+};
+
+jarmon.RrdQueryRemote.prototype.getData = function(startTime, endTime, dsId) {
+    /**
+     * Return a Flot compatible data series asynchronously.
+     *
+     * @method getData
+     * @param startTime {Number} The start timestamp
+     * @param endTime {Number} The end timestamp
+     * @param dsId {Variant} identifier of the RRD datasource (string or number)
+     * @return {Object} A Deferred which calls back with a flot data series.
+     **/
+    var endTimestamp = endTime/1000;
+
+    // Download the rrd if there has never been a download or if the last
+    // completed download had a lastUpdated timestamp less than the requested
+    // end time.
+    // Don't start another download if one is already in progress.
+    if(!this._download || (this._download.fired > -1 && this.lastUpdate < endTimestamp )) {
+        this._download = this.downloader(this.url)
+                .addCallback(
+                    function(self, binary) {
+                        // Upon successful download convert the resulting binary
+                        // into an RRD file and pass it on to the next callback
+                        // in the chain.
+                        var rrd = new RRDFile(binary);
+                        self.lastUpdate = rrd.getLastUpdate();
+                        return rrd;
+                    }, this);
+    }
+
+    // Set up a deferred which will call getData on the local RrdQuery object
+    // returning a flot compatible data object to the caller.
+    var ret = new MochiKit.Async.Deferred().addCallback(
+        function(self, startTime, endTime, dsId, rrd) {
+            return new jarmon.RrdQuery(rrd, self.unit).getData(startTime, endTime, dsId);
+        }, this, startTime, endTime, dsId);
+
+    // Add a pair of callbacks to the current download which will callback the
+    // result which we setup above.
+    this._download.addBoth(
+        function(ret, res) {
+            if(res instanceof Error) {
+                ret.errback(res);
+            } else {
+                ret.callback(res);
+            }
+            return res;
+        }, ret);
+
+    return ret;
+};
+
+/**
+ * Wraps RrdQueryRemote to provide access to a different RRD DSs within a
+ * single RrdDataSource.
+ *
+ * @class jarmon.RrdQueryDsProxy
+ * @constructor
+ * @param rrdQuery {Object} An RrdQueryRemote instance
+ * @param dsId {Variant} identifier of the RRD datasource (string or number)
+ **/
+jarmon.RrdQueryDsProxy = function(rrdQuery, dsId) {
+    this.rrdQuery = rrdQuery;
+    this.dsId = dsId;
+    this.unit = rrdQuery.unit;
+};
+
+jarmon.RrdQueryDsProxy.prototype.getData = function(startTime, endTime) {
+    /**
+     * Call I{RrdQueryRemote.getData} with a particular dsId
+     *
+     * @method getData
+     * @param startTime {Number} A unix timestamp marking the start time
+     * @param endTime {Number} A unix timestamp marking the start time
+     * @return {Object} A Deferred which calls back with a flot data series.
+     **/
+    return this.rrdQuery.getData(startTime, endTime, this.dsId);
+};
+
+
+/**
+ * A class for creating a Flot chart from a series of RRD Queries
+ *
+ * @class jarmon.Chart
+ * @constructor
+ * @param template {Object} A jQuery containing a single element into which the
+ *      chart will be drawn
+ * @param options {Object} Flot options which control how the chart should be
+ *      drawn.
+ **/
+jarmon.Chart = function(template, options) {
+    this.template = template;
+    this.options = jQuery.extend(true, {yaxis: {}}, options);
+
+    this.data = [];
+
+    var self = this;
+
+
+    // Listen for clicks on the legend items - onclick enable / disable the
+    // corresponding data source.
+    $('.graph-legend .legendItem', this.template[0]).live('click', function(e) {
+        self.switchDataEnabled($(this).text());
+        self.draw();
+    });
+
+
+    this.options['yaxis']['ticks'] = function(axis) {
+        /*
+         * Choose a suitable SI multiplier based on the min and max values from
+         * the axis and then generate appropriate yaxis tick labels.
+         *
+         * @param axis: An I{Object} with min and max properties
+         * @return: An array of ~5 tick labels
+         */
+        var siPrefixes = {
+            0: '',
+            1: 'K',
+            2: 'M',
+            3: 'G',
+            4: 'T'
+        }
+        var si = 0;
+        while(true) {
+            if( Math.pow(1000, si+1)*0.9 > axis.max ) {
+                break;
+            }
+            si++;
+        }
+
+        var minVal = axis.min/Math.pow(1000, si);
+        var maxVal = axis.max/Math.pow(1000, si);
+
+        var stepSizes = [0.01, 0.05, 0.1, 0.25, 0.5, 1, 5, 10, 25, 50, 100, 250];
+        var realStep = (maxVal - minVal)/5.0;
+
+        var stepSize, decimalPlaces = 0;
+        for(var i=0; i<stepSizes.length; i++) {
+            stepSize = stepSizes[i]
+            if( realStep < stepSize ) {
+                if(stepSize < 10) {
+                    decimalPlaces = 2;
+                }
+                break;
+            }
+        }
+
+        if(self.options.yaxis.tickDecimals != null) {
+            decimalPlaces = self.options.yaxis.tickDecimals;
+        }
+
+        var tickMin = minVal - minVal % stepSize;
+        var tickMax = maxVal - maxVal % stepSize + stepSize
+
+        var ticks = [];
+        for(var j=tickMin; j<=tickMax; j+=stepSize) {
+            ticks.push([
+                j*Math.pow(1000, si),
+                j.toFixed(decimalPlaces)
+            ]);
+        }
+
+        self.siPrefix = siPrefixes[si];
+
+        return ticks;
+    };
+};
+
+jarmon.Chart.prototype.addData = function(label, db, enabled) {
+    /**
+     * Add details of a remote RRD data source whose data will be added to this
+     * chart.
+     *
+     * @method addData
+     * @param label {String} The label for this data which will be shown in the
+     *               chart legend
+     * @param db {String} The url of the remote RRD database
+     * @param enabled {Boolean} true if you want this data plotted on the chart,
+     *      false if not.
+     **/
+    if(typeof enabled == 'undefined') {
+        enabled = true;
+    }
+    this.data.push([label, db, enabled]);
+};
+
+jarmon.Chart.prototype.switchDataEnabled = function(label) {
+    /**
+     * Enable / Disable a single data source
+     *
+     * @method switchDataEnabled
+     * @param label {String} The label of the data source to be enabled /
+     *      disabled.
+     **/
+    for(var i=0; i<this.data.length; i++) {
+        if(this.data[i][0] == label) {
+            this.data[i][2] = !this.data[i][2];
+        }
+    }
+};
+
+jarmon.Chart.prototype.setTimeRange = function(startTime, endTime) {
+    /**
+     * Alter the time range of this chart and redraw
+     *
+     * @method setTimeRange
+     * @param startTime {Number} The start timestamp
+     * @param endTime {Number} The end timestamp
+     **/
+    this.startTime = startTime;
+    this.endTime = endTime;
+    return this.draw();
+}
+
+jarmon.Chart.prototype.draw = function() {
+    /**
+     * Draw the chart
+     * A 'chart_loading' event is triggered before the data is requested
+     * A 'chart_loaded' event is triggered when the chart has been drawn
+     *
+     * @method draw
+     * @return {Object} A Deferred which calls back with the chart data when
+     *      the chart has been rendered.
+     **/
+    this.template.addClass('loading');
+
+    var result;
+    var results = [];
+    for(var i=0; i<this.data.length; i++) {
+        if(this.data[i][2]) {
+            result = this.data[i][1].getData(this.startTime, this.endTime);
+        } else {
+            // If the data source has been marked as disabled return a fake
+            // empty dataset
+            // 0 values so that it can contribute to a stacked chart.
+            // 0 linewidth so that it doesn't cause a line in stacked chart
+            result = new MochiKit.Async.Deferred();
+            result.callback({
+                data: [
+                    [this.startTime, 0],
+                    [this.endTime, 0]
+                ],
+                lines: {
+                    lineWidth: 0
+                }
+            });
+        }
+
+        results.push(result);
+    }
+
+    return MochiKit.Async.gatherResults(results)
+            .addCallback(
+                function(self, data) {
+                    var i, label, disabled = [];
+                    unit = '';
+                    for(i=0; i<data.length; i++) {
+                        label = self.data[i][0];
+                        if(label) {
+                            data[i].label = label;
+                        }
+                        if(typeof data[i].unit != 'undefined') {
+                            // Just use the last unit for now
+                            unit = data[i].unit;
+                        }
+                        if(!self.data[i][2]) {
+                            disabled.push(label);
+                        }
+                    }
+
+                    $.plot(self.template.find('.chart'), data, self.options);
+
+                    var yaxisUnitLabel = $('<div>').text(self.siPrefix + unit)
+                                                   .css({width: '100px',
+                                                         position: 'absolute',
+                                                         top: '80px',
+                                                         left: '-90px',
+                                                         'text-align': 'right'});
+                    self.template.find('.chart').append(yaxisUnitLabel);
+
+                    // Manipulate and move the flot generated legend to an
+                    // alternative position.
+                    // The default legend is formatted as an HTML table, so we
+                    // grab the contents of the cells and turn them into
+                    // divs.
+                    // Actually, formatting the legend first as a one column
+                    // table is useful as it generates an optimum label element
+                    // width which we can copy to the new divs + a little extra
+                    // to accomodate the color box
+                    var legend = self.template.find('.graph-legend');
+                    legend.empty();
+                    self.template.find('.legendLabel')
+                        .each(function(i, el) {
+                            var orig = $(el);
+                            var label = orig.text();
+                            var newEl = $('<div />')
+                                .attr('class', 'legendItem')
+                                .attr('title', 'Data series switch - click to turn this data series on or off')
+                                .width(orig.width()+20)
+                                .text(label)
+                                .prepend(orig.prev().find('div div').clone().addClass('legendColorBox'))
+                                .appendTo(legend);
+                            // The legend label is clickable - to enable /
+                            // disable different data series. The disabled class
+                            // results in a label formatted with strike though
+                            if( $.inArray(label, disabled) > -1 ) {
+                                newEl.addClass('disabled');
+                            }
+                        })
+                        .remove();
+                    legend.append($('<div />').css('clear', 'both'));
+                    self.template.find('.legend').remove();
+
+                    yaxisUnitLabel.position(self.template.position());
+                    return data;
+                }, this)
+            .addErrback(
+                function(self, failure) {
+                    self.template.text('error: ' + failure.message);
+                }, this)
+            .addBoth(
+                function(self, res) {
+                    self.template.removeClass('loading');
+                    return res;
+                }, this);
+};
+
+
+jarmon.Chart.fromRecipe = function(recipes, templateFactory, downloader) {
+    /**
+     * A static factory method to generate a list of I{Chart} from a list of
+     * recipes and a list of available rrd files in collectd path format.
+     *
+     * @method fromRecipe
+     * @param recipes {Array} A list of recipe objects.
+     * @param templateFactory {Function} A callable which generates an html
+     *      template for a chart.
+     * @param downloader {Function} A download function which returns a Deferred
+     * @return {Array} A list of Chart objects
+     **/
+
+    var charts = [];
+    var dataDict = {};
+
+    var recipe, chartData, template, c, i, j, ds, label, rrd, unit, re, match;
+
+    for(i=0; i<recipes.length; i++) {
+        recipe = recipes[i];
+        chartData = [];
+
+        for(j=0; j<recipe['data'].length; j++) {
+            rrd = recipe['data'][j][0];
+            ds = recipe['data'][j][1];
+            label = recipe['data'][j][2];
+            unit = recipe['data'][j][3];
+            if(typeof dataDict[rrd] == 'undefined') {
+                dataDict[rrd] = new jarmon.RrdQueryRemote(rrd, unit, downloader);
+            }
+            chartData.push([label, new jarmon.RrdQueryDsProxy(dataDict[rrd], ds)]);
+        }
+        if(chartData.length > 0) {
+            template = templateFactory();
+            template.find('.title').text(recipe['title']);
+            c = new jarmon.Chart(template, recipe['options']);
+            for(j=0; j<chartData.length; j++) {
+                c.addData.apply(c, chartData[j]);
+            }
+            charts.push(c);
+        }
+    }
+    return charts;
+};
+
+
+// Options common to all the chart on this page
+jarmon.Chart.BASE_OPTIONS = {
+    grid: {
+        clickable: false,
+        borderWidth: 1,
+        borderColor: "#000",
+        color: "#000",
+        backgroundColor: "#fff",
+        tickColor: "#eee"
+    },
+    legend: {
+        position: 'nw',
+        noColumns: 1
+    },
+    selection: {
+        mode: 'x'
+    },
+    series: {
+        points: { show: false },
+        lines: {
+            show: true,
+            steps: false,
+            shadowSize: 0,
+            lineWidth: 1
+        },
+        shadowSize: 0
+    },
+    xaxis: {
+        mode: "time",
+        tickFormatter: jarmon.localTimeFormatter
+    }
+};
+
+// Extra options to generate a stacked chart
+jarmon.Chart.STACKED_OPTIONS = {
+    series: {
+        stack: true,
+        lines: {
+            fill: 0.5
+        }
+    }
+};
+
+
+// A selection of useful time ranges
+jarmon.timeRangeShortcuts = [
+    ['last hour', function(now) { return [now-60*60*1000*1, now]; }],
+    ['last 3 hours', function(now) { return [now-60*60*1000*3, now]; }],
+    ['last 6 hours', function(now) { return [now-60*60*1000*6, now]; }],
+    ['last 12 hours', function(now) { return [now-60*60*1000*12, now]; }],
+    ['last day', function(now) { return [now-60*60*1000*24, now]; }],
+    ['last week', function(now) { return [now-60*60*1000*24*7, now]; }],
+    ['last month', function(now) { return [now-60*60*1000*24*31, now]; }],
+    ['last year', function(now) { return [now-60*60*1000*24*365, now]; }]
+];
+
+
+/**
+ * Presents the user with a form and a timeline with which they can choose a
+ * time range and co-ordinates the refreshing of a series of charts.
+ *
+ * @class jarmon.ChartCoordinator
+ * @constructor
+ * @param ui {Object} A one element jQuery containing an input form and
+ *      placeholders for the timeline and for the series of charts.
+ **/
+jarmon.ChartCoordinator = function(ui) {
+    var self = this;
+    this.ui = ui;
+    this.charts = [];
+
+    // Style and configuration of the range timeline
+    this.rangePreviewOptions = {
+        grid: {
+            borderWidth: 1
+        },
+        selection: {
+            mode: 'x'
+        },
+        xaxis: {
+            mode: 'time',
+            tickFormatter: jarmon.localTimeFormatter
+        },
+        yaxis: {
+            ticks: []
+        }
+    };
+
+    var options = this.ui.find('select[name="from_standard"]');
+    for(var i=0; i<jarmon.timeRangeShortcuts.length; i++) {
+        options.append($('<option />').text(jarmon.timeRangeShortcuts[i][0]));
+    }
+
+    // Append a custom option for when the user selects an area of the graph
+    options.append($('<option />').text('custom'));
+    // Select the first shortcut by default
+    options.val(jarmon.timeRangeShortcuts[0][0]);
+
+    options.bind('change', function(e) {
+        // No point in updating if the user chose custom.
+        if($(this).val() != 'custom') {
+            self.update();
+        }
+    });
+
+    // Update the time ranges and redraw charts when the custom datetime inputs
+    // are changed
+    this.ui.find('[name="from_custom"]').bind('change',
+        function(e) {
+            self.ui.find('[name="from_standard"]').val('custom');
+            var tzoffset = parseInt(self.ui.find('[name="tzoffset"]').val());
+            self.setTimeRange(new Date(this.value + ' UTC').getTime() - tzoffset, null);
+            self.update();
+        }
+    );
+
+    this.ui.find('[name="to_custom"]').bind('change',
+        function(e) {
+            self.ui.find('[name="from_standard"]').val('custom');
+            var tzoffset = parseInt(self.ui.find('[name="tzoffset"]').val());
+            self.setTimeRange(null, new Date(this.value + ' UTC').getTime() - tzoffset);
+            self.update();
+        }
+    );
+
+    // Populate a list of tzoffset options if the element is present in the
+    // template as a select list
+    tzoffsetEl = this.ui.find('[name="tzoffset"]');
+    if(tzoffsetEl.is('select')) {
+        var label, val;
+        for(var i=-12; i<=12; i++) {
+            label = 'UTC';
+            val = i;
+            if(val >= 0) {
+                label += ' + ';
+            } else {
+                label += ' - ';
+            }
+            val = Math.abs(val).toString();
+            if(val.length == 1) {
+                label += '0';
+            }
+            label += val + '00';
+            tzoffsetEl.append($('<option />').attr('value', i*60*60*1000).text(label));
+        }
+
+        tzoffsetEl.bind('change', function(e) {
+            self.update();
+        });
+    }
+
+    // Default timezone offset based on localtime
+    var tzoffset = -1 * new Date().getTimezoneOffset() * 60 * 1000;
+    tzoffsetEl.val(tzoffset);
+
+    // Update the time ranges and redraw charts when the form is submitted
+    this.ui.find('[name="action"]').bind('click', function(e) {
+        self.update();
+        return false;
+    });
+
+    // When a selection is made on the range timeline, or any of my charts
+    // redraw all the charts.
+    this.ui.bind("plotselected", function(event, ranges) {
+        self.ui.find('[name="from_standard"]').val('custom');
+        self.setTimeRange(ranges.xaxis.from, ranges.xaxis.to);
+        self.update();
+    });
+};
+
+
+jarmon.ChartCoordinator.prototype.update = function() {
+    /**
+     * Grab the start and end time from the ui form, highlight the range on the
+     * range timeline and set the time range of all the charts and redraw.
+     *
+     * @method update
+     **/
+
+    var selection = this.ui.find('[name="from_standard"]').val();
+
+    var now = new Date().getTime();
+    for(var i=0; i<jarmon.timeRangeShortcuts.length; i++) {
+        if(jarmon.timeRangeShortcuts[i][0] == selection) {
+            range = jarmon.timeRangeShortcuts[i][1](now);
+            this.setTimeRange(range[0], range[1]);
+            break;
+        }
+    }
+
+    var startTime = parseInt(this.ui.find('[name="from"]').val());
+    var endTime = parseInt(this.ui.find('[name="to"]').val());
+    var tzoffset = parseInt(this.ui.find('[name="tzoffset"]').val());
+
+    this.ui.find('[name="from_custom"]').val(
+        new Date(startTime + tzoffset).toUTCString().split(' ').slice(1,5).join(' '));
+    this.ui.find('[name="to_custom"]').val(
+        new Date(endTime + tzoffset).toUTCString().split(' ').slice(1,5).join(' '));
+
+    this.rangePreviewOptions.xaxis.tzoffset = tzoffset;
+
+    var chartsLoading = [];
+    for(var i=0; i<this.charts.length; i++){
+        this.charts[i].options.xaxis.tzoffset = tzoffset;
+        // Don't render charts which are not currently visible
+        if(this.charts[i].template.is(':visible')) {
+            chartsLoading.push(
+                this.charts[i].setTimeRange(startTime, endTime));
+        }
+    }
+    return MochiKit.Async.gatherResults(chartsLoading).addCallback(
+        function(self, startTime, endTime, chartData) {
+
+            var firstUpdate = new Date().getTime();
+            var lastUpdate = 0;
+
+            for(var i=0; i<chartData.length; i++) {
+                for(var j=0; j<chartData[i].length; j++) {
+                    if(chartData[i][j].firstUpdated < firstUpdate) {
+                        firstUpdate = chartData[i][j].firstUpdated;
+                    }
+                    if(chartData[i][j].lastUpdated > lastUpdate) {
+                        lastUpdate = chartData[i][j].lastUpdated;
+                    }
+                }
+            }
+
+            var ranges = {
+                xaxis: {
+                    from: Math.max(startTime, firstUpdate),
+                    to: Math.min(endTime, lastUpdate)
+                }
+            };
+
+            // Add a suitable extended head and tail to preview graph time axis
+            var HOUR = 1000 * 60 * 60;
+            var DAY = HOUR * 24;
+            var WEEK = DAY * 7;
+            var MONTH = DAY * 31;
+            var YEAR = DAY * 365;
+            var periods = [HOUR, HOUR*6, HOUR*12,
+                           DAY, DAY*3,
+                           WEEK, WEEK*2,
+                           MONTH, MONTH*3, MONTH*6, YEAR];
+
+            var range = ranges.xaxis.to - ranges.xaxis.from;
+            for(var i=0; i<periods.length; i++) {
+                if(range <= periods[i]) {
+                    i++;
+                    break;
+                }
+            }
+
+            // Dummy data for the range timeline
+            var data = [
+                [Math.max(ranges.xaxis.from - periods[i-1], firstUpdate), 1],
+                [Math.min(ranges.xaxis.to + periods[i-1], lastUpdate), 1]];
+
+            self.rangePreview = $.plot(self.ui.find('.range-preview'), [data],
+                                       self.rangePreviewOptions);
+
+            self.rangePreview.setSelection(ranges, true);
+        }, this, startTime, endTime);
+};
+
+jarmon.ChartCoordinator.prototype.setTimeRange = function(from, to) {
+    /**
+     * Set the start and end time fields in the form and trigger an update
+     *
+     * @method setTimeRange
+     * @param startTime {Number} The start timestamp
+     * @param endTime {Number} The end timestamp
+     **/
+    if(from != null) {
+        this.ui.find('[name="from"]').val(from);
+    }
+    if(to != null) {
+        this.ui.find('[name="to"]').val(to);
+    }
+};
+
+jarmon.ChartCoordinator.prototype.init = function() {
+    /**
+     * Reset all charts and the input form to the default time range - last hour
+     *
+     * @method init
+     **/
+    this.update();
+};
+
+/**
+ * Limit the number of parallel async calls
+ *
+ * @class jarmon.Parallimiter
+ * @constructor
+ * @param limit {Number} The maximum number of in progress calls
+ **/
+jarmon.Parallimiter = function(limit) {
+    this.limit = limit || 1;
+    this._callQueue = [];
+    this._currentCallCount = 0;
+};
+
+jarmon.Parallimiter.prototype.addCallable = function(callable, args) {
+    /**
+    * Add a function to be called when the number of in progress calls drops
+    * below the configured limit
+    *
+    * @method addCallable
+    * @param callable {Function} A function which returns a Deferred.
+    * @param args {Array} A list of arguments to pass to the callable
+    * @return {Object} A Deferred which fires with the result of the callable
+    *       when it is called.
+    **/
+    var d = new MochiKit.Async.Deferred();
+    this._callQueue.unshift([d, callable, args]);
+    this._nextCall();
+    return d;
+};
+
+jarmon.Parallimiter.prototype._nextCall = function() {
+    if(this._callQueue.length > 0) {
+        if(this._currentCallCount < this.limit) {
+            this._currentCallCount++;
+            var nextCall = this._callQueue.pop();
+            nextCall[1].apply(null, nextCall[2]).addBoth(
+                function(self, d, res) {
+                    d.callback(res);
+                    self._currentCallCount--;
+                    self._nextCall();
+                }, this, nextCall[0]);
+        }
+    }
+};