Flot: how to style numbers within bar-charts?

问题:

I'm using FlotCharts and it's plugin flot.barnumbers (Demo) to display charts.

I need to display the numbers within the bar, it works. Unfortunately I've no idea how to style the numbers and cannot find anything in the Docs or via Google.

I'd like to use something like (apparently not possible):

bars: {
    numbers: {
        numberFormatter: function(v, bar) {
            return '<div class="pimp-my-number-class">'+ v +'</div>';               
        }
    }
}

Does anyone have an idea, how to fix this problem?

Thank's in advance!

回答1:

One of the nicest things about flot is that it provides the basics and then gets out of your way. Here's a quick code example where I've implemented this myself (ie no plugins). It's short and sweet and you have complete control over appearance.

$(function() {

    dsHook = function(plot, canvascontext, series){
        for (var i = 0; i < series.data.length; i++){ // loop the series
           var offset = plot.offset(); // offset of canvas to body
           var dP = series.data[i]; // our data point
           var pos = plot.p2c({x: dP[0], y: dP[1]}); // position of point           
           var barWidth = plot.p2c({x: dP[0]+series.bars.barWidth, y: dP[1]}).left - pos.left; // calc width of bar
           pos.left += offset.left; pos.top += offset.top; //adjust position for offset
           var aDiv = $('<div></div>').css({'width':barWidth, 'background-color':'green','color':'white','text-align':'center','position':'absolute','left': pos.left,'top':pos.top}).text(dP[1]).appendTo("body"); // add an absolute div with the number
        }
    }

    var d2 = [[0, 3], [4, 8], [8, 5], [9, 13]];

    somePlot = $.plot("#placeholder", [{
            data: d2,
            bars: { show: true }
        }],
        { hooks: { drawSeries: [dsHook] } }
    );
});

回答2:

flot.barnumbers doesn't support styling of the inserted numbers. You have to add that yourself to the code. Have a look at Drawing text using a canvas.

回答3:

I would try to achive your desired layout by using a combination of annotations like here and a second data series behind your actual series. The second series then should have equal x values as your original series. To the corresponding y values you add a constant (e.g. 2).

You can style the annotations and the second series as you like. The fiddly part would be to place the annotations at correct positions.