The SVG text function

• The options to the function
• A full source code example
• Using carriage returns in your text
• Disabling events for the text
• The RGraph.SVG.text.find() function
• The defaults object

The RGraph.SVG.text function is a function that can be used to add text to an SVG tag - in RGraphs case this will be a chart.

It has several features that make common tasks (eg font selection, size, font-weight and alignment) significantly easier than creating the text tags yourself and adding them to the SVG tag.

It's used by all of the charts libraries and there's no reason that you shouldn't use the function too if you need to add extra text to your chart.

It looks like this (assume that you have a chart object called obj):

RGraph.SVG.text({
    object:     obj,
    parent:     obj.svg.all,
    tag:        'Some text',
    text:       'A nice red\r\nBar chart!',
    x:          50,
    y:          260,
    halign:     'left',
    valign:     'bottom',
    font:       'Verdana',
    size:       18,
    bold:       true,
    italic:     true,
    color:      'blue',
    background: 'rgba(232,232,232,0.75)',
    padding:    5,
    link:       'http://www.google.com',
    linkTarget: '_blank'
});

The options to the function

Here's a breakdown of the options that are available to you:

A full source code example

Here's an example of a full chart. Notice that, unlike the canvas libraries, even though we're drawing on the chart and have dynamic features enabled (ie tooltips) the extra text that is being added doesn't need to be added in the draw event. This is because with SVG the scene is not repeatedly being redrawn like a canvas chart is.

<script>
    obj = new RGraph.SVG.Bar({
        id: 'cc',
        data: [7,6,5,2,3,5,8],
        options: {
            colors: ['gradient(red:#faa)'],
            xaxisLabels: ['Mon','Tue','Wed','Thu','Fri','Sat','Sun'],
            tooltips: ['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday
            xaxis: false,
            yaxis: false,
            shadow: true,
            backgroundGridVlines: false,
            backgroundGridBorder: false
        }
    }).draw();
    
    RGraph.SVG.text({
        object:     obj,
        parent:     obj.svg.all,
        tag:        'Some text',
        text:       'A nice red\r\nBar chart!',
        x:          50,
        y:          260,
        halign:     'left',
        valign:     'bottom',
        font:       'Verdana',
        size:       18,
        bold:       true,
        italic:     true,
        color:      'blue',
        background: 'rgba(232,232,232,0.75)',
        padding:    5,
        link:       'http://www.google.com',
        linkTarget: '_blank'
    });
</script>

Using carriage returns in your text

Carriage returns are catered for as of version 4.65 - all you need to do is use \r\n in your text - as you might expect. The example above uses a carriage return so that the text spans two lines.

Disabling events for the text

If you don't want the text to accept mouse events (such as click and mouseover) then you can disable them by using the events property. By default this is true - so the text will be liable for the click and mouseover events. But if you set this property to false then any events will be ignored and the text will be transparent to the mouse - allowing you to click elements behind the text as if the text wasn't there.

The RGraph.SVG.text.find() function

Like the canvas libraries there's an API function that can help you get hold of the text nodes that RGraph adds to your charts: the RGraph.SVG.text.find function. This function is very similar to the canvas version in its operation - here's an example.

<script>
    obj = new RGraph.SVG.Bar({
        id: 'cc',
        data: [4,8,6,3,5,8,4],
        options: {
            xaxisLabels: ['Mon','Tue','Wed','Thu','Fri','Sat','Sun'],
            labelsAbove: true,
            labelsAboveUnitsPost: '%',
            marginInner: 20,
            textSize: 20,
            textBold: true
        }
    }).draw();

    RGraph.SVG.text.find({
        object: obj,         // Give the object to get the relevant SVG tag
        // svg: obj.svg,     // Or give the actual SVG tag itself (you could also use document.getElementById() here)
        tag: 'labels.above', // Exact match tag to find (eg labels.above
        // tag: /^labels/    // A regex that matches the text nodes that we want
        // text: 'Thu'       // Exact match text to find (eg Mon)
        // text: /^t/i       // A regex that matches the text nodes that we want

        callback: function (opt)
        {
            alert(opt.nodes); // This is the nodes that were found
            alert(opt.nodes.length + ' node(s) found')
        }
    });
</script>

The options that you can give this function are:

• id - The id of the chart. If you prefer you can give the object argument instead.
• object - This can be given instead of the id option and is used to get the SVG tag.
• tag - This can be a string or a regular expression that is matched against the tag attribute (that RGraph adds to text nodes) of the text.
• text - This can be a string or a regular expression that is matched against the text (that you see) itself.
• callback - The optional callback can be a function that is called when the search has found any matching text nodes. If no nodes are found then the function is still called but with an empty array.

There's an example of using this function in the RGraph.SVG.text.find HOWTO document.

The defaults object

As with the canvas RGraph.text function, if you have a lot of text to add to your canvas then you may want to use the defaults object. As it sounds, this object allows you to set the default values that are used for the text function so you can set the values once instead of on every call to the function. For example:

obj = new RGraph.SVG.Bar({
    id: 'cc',
    data: [4,8,6,4,5,3,5],
    options: {
    }
}).draw();

RGraph.SVG.text.defaults = {
    font:  'Comic sans MS',
    size:  20,
    bold:  true,
    color: 'blue'
};

RGraph.SVG.text({
    object: obj,
    x: 50,
    y: 50,
    text: 'Some example text!'
});

RGraph.SVG.text({
    object: obj,
    x: 50,
    y: 100,
    italic: true,
    bold: false,
    text: 'Some more example text but in italic instead of bold!'
});