How to either determine SVG text box width, or force line breaks after 'x' characters?

Question

I'm creating an SVG text box using the Raphael library, and filling it with a dynamic string which is extracted from an XML document.

Sometimes, this string is longer than the canvas I am placing the text box on, so I need to either limit the width of the box which will itself force the line breaks (I can't find any evidence of this being possible) OR ensure that a '\n' line break is inserted after a certain amount of characters.

So (1) is this the best option? And (2) how would I do this?

Answer 1

There isn't an attribute for text wrapping, but there is a simple trick you can use. Add one word at a time to a text object and when it gets too wide, add a line feed. You can use the getBBox() function to determine the width. Basically, you emulate an old fashioned typewriter. Here is a sample of some code that will do this for you. You could easily turn this into a simple function that takes the text and a width.

var r = Raphael(500, 500);
var t = r.text(100, 100).attr('text-anchor', 'start');
var maxWidth = 100;

var content = "Mauris mauris ante, blandit et, ultrices a, suscipit eget, quam. Integer ut neque. Vivamus nisi metus, molestie vel, gravida in, condimentum sit amet, nunc. Nam a nibh. Donec suscipit eros. Nam mi. Proin viverra leo ut odio. Curabitur malesuada. Vestibulum a velit eu ante scelerisque vulputate. ";
var words = content.split(" ");

var tempText = "";
for (var i=0; i<words.length; i++) {
  t.attr("text", tempText + " " + words[i]);
  if (t.getBBox().width > maxWidth) {
    tempText += "\n" + words[i];
  } else {
    tempText += " " + words[i];
  }
}

t.attr("text", tempText.substring(1));