Starting today, we�re introducing a new set of operators, which we�re calling lambda expressions, that allow you to apply rules to whole sets of data (think posts, comments, or labels), rather than just individual instances.
Let�s say you wanted to add a flower image to all posts with the label �Flower,� for example. With lambda expressions, simply define a variable name that each item in the set will take, and then refer to the variable name as though it were each item.
<!-- Show a Flower image if the post has the label flower -->
<b:if cond='data:post.labels any (l => l.name == "Flower")'>
<img src=�/img/flower.jpg� />
<b:if/>
An example of adding a flower icon to posts labelled 'Flower'
There�s lots more that you can do using lambda expressions, like only showing posts in your feed with a given label or quickly calculating how many posts you have with a given number of comments. For a full list of the new lambda expressions available, check out the help forum.
Happy Blogging! ??
Posted by Luke, Software Engineer