Some Render API properties, like #pre_render, #element_validate, and #lazy_builder are considered callable. Rather than receiving a static value, they contain a pointer to code that should be called at a specific time during the process of rendering a render element. Callbacks are used in some cases to return a value that can be substituted into the render array, and in other cases given the opportunity to manipulate the current element in the array directly.
In this tutorial, we'll:
- Look at what callbacks are
- List some common callback properties
- Show various ways that callback code can be defined
- Discuss how to choose which method to use
By the end of this tutorial, you should be able to define an appropriate value for any Render API property that expects a callback, and define the logic that is executed when the callback is triggered.
Over the years we've developed some techniques for practicing that we wanted to share. At Drupalize.Me we take hugging seriously. In this tutorial we'll look at the art, and science, of giving a good hug. The Merriam Webster dictionary defines the word hug as; squeeze (someone) tightly in one's arms, typically to express affection.
Did you know there are all kinds of different hugs that you can give? In this tutorial we'll look at:
- Defining what a hug is
- Some of the many types of hugs in the world today
- Precautions you may want to familiarize yourself with before hugging
- And the importance of proper technique
Lets go ahead and get started shall we?