条形图上的jqplot工具提示

Question

I'm using the jquery plugin jqplot for plotting some bar charts. on hover, I'd like to display the tick for the bar and its value on a tooltip. I've tried

highlighter: { show: true, 
            showTooltip: true,      // show a tooltip with data point values.
            tooltipLocation: 'nw',  // location of tooltip: n, ne, e, se, s, sw, w, nw.
            tooltipAxes: 'both',    // which axis values to display in the tooltip, x, y or both.
            lineWidthAdjust: 2.5   // pixels to add to the size line stroking the data point marker
            }

but it doesn't work. the bar visually gets lighter, and there's a small dot on the top (which would ideally go away--probably from line chart renderer stuff), but there is no tooltip anywhere. Anyone know how I can do this? I'll have lots of bars so the x-axis will be cluttered and kind of a mess if I show them down there only.

Answer 1

I go through jqplot.highlighter.js and find an undocumented property: tooltipContentEditor . I use it to customize the tooltip to display x-axis label.

Use something like this:

highlighter:{
        show:true,
        tooltipContentEditor:tooltipContentEditor
    },

function tooltipContentEditor(str, seriesIndex, pointIndex, plot) {
    // display series_label, x-axis_tick, y-axis value
    return plot.series[seriesIndex]["label"] + ", " + plot.data[seriesIndex][pointIndex];
}

Answer 2

nevermind, I did a roundabout way to create my own tooltip via jquery.

I left my highlighter settings as they were in my question (though you probably don't need the tooltip stuff).

In my js file after the bar chart is set up (after $.jqplot('chart', ... ) I set up an on mouse hover binding, as some of the examples showed. I modified it like this:

 $('#mychartdiv').bind('jqplotDataHighlight', 
        function (ev, seriesIndex, pointIndex, data ) {
            var mouseX = ev.pageX; //these are going to be how jquery knows where to put the div that will be our tooltip
            var mouseY = ev.pageY;
            $('#chartpseudotooltip').html(ticks_array[pointIndex] + ', ' + data[1]);
            var cssObj = {
                  'position' : 'absolute',
                  'font-weight' : 'bold',
                  'left' : mouseX + 'px', //usually needs more offset here
                  'top' : mouseY + 'px'
                };
            $('#chartpseudotooltip').css(cssObj);
            }
    );    

    $('#chartv').bind('jqplotDataUnhighlight', 
        function (ev) {
            $('#chartpseudotooltip').html('');
        }
    );

explanation: ticks_array is previously defined, containing the x axis tick strings. jqplot's data has the current data under your mouse as an [x-category-#, y-value] type array. pointIndex has the current highlighted bar #. Basically we will use this to get the tick string.

Then I styled the tooltip so that it appears close to where the mouse cursor is. You will probably need to subtract from mouseX and mouseY a bit if this div is in other positioned containers.

you can then style #chartpseudotooltip in your css. If you want the default styles you can just add it to .jqplot-highlighter-tooltip in the the jqplot.css.

hope this is helpful to others!

Answer 3

I am using the version of the highlighter plugin on the following link:

https://github.com/tryolabs/jqplot-highlighter

The parameters I am using:

highlighter: {
    show:true,
    tooltipLocation: 'n',
    tooltipAxes: 'pieref', // exclusive to this version
    tooltipAxisX: 20, // exclusive to this version
    tooltipAxisY: 20, // exclusive to this version
    useAxesFormatters: false,
    formatString:'%s, %P',
}

The new parameters ensure a fixed location where the tooltip will appear. I prefer to place it on the upper left corner to avoid problems with resizing the container div.