# SVG text wrapping The wrap function below is based on [one by Mike Bostock](https://bl.ocks.org/mbostock/7555321). It takes a D3 selector of text elements and wraps the text into tspan elements. With a D3 text selection called text, you can call the function like this: text.call(wrap, width, dyAdjust, lineHeightEms, lineHeightSquishFactor, splitOnHyphen, centreVertically) ## The <text> element needs x and y attributes It's necessary to set the x and y attributes on each <text> element (even if just to 0) before calling the wrap function. Otherwise, some lines of text may be positioned incorrectly. ## Parameters: - width: The maximum width of a label. (This may be exceeded if an individual word is longer than this width.) - dyAdjust: Add this many ems to the y position of each label. A value of .35 seems to work well. (Using the SVG dominant-baseline attribute is probably better but I don't think it works in IE11.) - lineHeightEms: The vertical distance in ems from the top of one line to the top of the next line. - lineHeightSquishFactor: If this equals 1, it does nothing. If it is less than 1, it squishes the lines together a bit more if a label has three or more lines of text. - splitOnHyphen: Allow a word to be split just after a hyphen? (Default: true) - centreVertically: Centre-align the text vertically? (Default: true) The final four parameters are optional.