I want to render line chart using grouping on particular field

Question

Currently I am rendering single line chart using json data which is as follow :

{"eventType":"A","startOpen":"0","asOfDate":"21-OCT-13","intervalNo":0},
{"eventType":"A","startOpen":"47","asOfDate":"21-OCT-13","intervalNo":1},
{"eventType":"A","startOpen":"60","asOfDate":"21-OCT-13","intervalNo":2},
{"eventType":"B","startOpen":"79","asOfDate":"21-OCT-13","intervalNo":4},
{"eventType":"B","startOpen":"90","asOfDate":"21-OCT-13","intervalNo":6}

I am plotting graph startOpen against intervalNo. Now I want to plot the graph using grouping on eventType field. Means for above data two line should be drawn in single chart, one for eventType A and another for eventType B.

Appreciate your any kind of help. Thank you :)

My current code for chart :

Ext.define("TestBug.view.TrendsChart", {
extend: "Ext.chart.Chart",
alias: "widget.trendschart",
store: "Trends",
style: 'background:#fff',
animate: true,
shadow: true,
groupField:'eventType',

legend: {position: 'right'},
axes: [
    {
        type: "numeric",
        position: "left",
        fields: "intervalNo",
        title:"Interval No",
        grid: {
            odd: {
                opacity: 1,
                fill: '#ddd',
                stroke: '#bbb',
                'stroke-width': 0.5
            }
        }
   },
    {
        type: "numeric",
        position: "bottom",
        fields: "startOpen",
        title: 'Start Open'
    }
],
series: [
    {
        type: "line",
        axis: "left",
        xField: "startOpen",
        yField: "intervalNo",
        gField:'eventType',
        markerConfig: {
            type: 'circle',
            size: 4,
            radius: 4,
            'stroke-width': 0
        }
    }
]
});

Answer 1

In order to plot multiple lines width different x values, you have to use multiple line series. Value points with value of undefined will be skipped, that is they won't be drawn in the chart.

Here's how to adapt your example data to do that (fiddle):

Ext.define("TestBug.view.TrendsChart", {
    extend: "Ext.chart.Chart",
    alias: "widget.trendschart",

    store: {
        fields: [
            'eventType', 
            {name: 'startOpen', type: 'int'}, 
            'asOfDate', 
            'intervalA',
            'intervalB'
        ]
        ,data: [
            {"eventType":"A","startOpen":"0","intervalA":0,"intervalB":undefined},
            {"eventType":"A","startOpen":"47","intervalA":1,"intervalB":undefined},
            {"eventType":"A","startOpen":"35","intervalA":undefined,"intervalB":2},
            {"eventType":"B","startOpen":"79","intervalA":undefined,"intervalB":4},
            {"eventType":"B","startOpen":"90","intervalA":undefined,"intervalB":6}
        ]
    },

    style: 'background:#fff',
    animate: true,
    shadow: true,
    groupField: 'eventType',

    legend: {
        position: 'right'
    },

    axes: [{
        type: "numeric",
        position: "left",
        fields: ["intervalA", "intervalB"],
        title: "Interval No",
        grid: {
            odd: {
                opacity: 1,
                fill: '#ddd',
                stroke: '#bbb',
                'stroke-width': 0.5
            }
        }
    },{
        type: "numeric",
        position: "bottom",
        fields: "startOpen",
        title: 'Start Open'
    }],

    series: [{
        type: "line",
        axis: "left",
        xField: "startOpen",
        yField: "intervalA",
        title: "A"
    },{
        type: "line",
        axis: 'left',
        xField: 'startOpen',
        yField: 'intervalB',
        title: "B"
    }]
});

Ext.widget('trendschart', {
    renderTo: Ext.getBody()
    ,width: 600
    ,height: 300
});