In QGIS 2.18 there is an option to wrap text based on a certain character. What I need is to automatically wrap my text on the ' ' (space) character IF the character length exceeds the size of my legend box. Question is: how do I get an expression builder in the supplied warp box?
In this example I warped on the caracter '_'
There is no way to wrap a text in the legend based on the number of characters. As you can see in wrap text in the legend, it does not support expressions. There is no expression button beside the Wrap text in legend to use . If you want to wrap the text based on space, just hit the space on you keyboard and it will be wrapped:
Before pressing the space:
After:
I've found a bit of a work around for this - if you go into 'legend items' -> double click a layer to amend the text -> hit 'enter' on where you would like the text to wrap it starts a new line so you can manually create the wraps (bit tedious if you have a lot of layers showing)
As was brought to my attention in the corresponding feature request on GitHub, there is a very similar feature that made it into QGIS 3.44 (set to become LTR at the end of February 2026).
You can now use "Item Properties - Word Wrapping - Maximum length" to wrap text at a certain length (not number of characters).
See some more info in the pull request (including video) and the word wrapping documentation.
