Tell me about read-only blocks on Grok

Read-only blocks is a new feature for our Blockly courses. You'll find this feature appearing gradually throughout our courses on Grok as we update them. 

What are read-only blocks?

Read-only blocks are blocks that we have prefilled in the code editor and marked as read-only in any or all of three ways:

• The block cannot be moved: Immovable blocks are used to preserve code structure. They cannot be separated from blocks they are joined to, and inner blocks cannot be removed from outer blocks. 
• The block cannot be edited: Uneditable blocks cannot be changed - e.g. you cannot edit a string or number, or select a different option from a drop-down menu.
• The block cannot be deleted: Undeletable blocks cannot be removed from the workspace. Nothing will happen if you drag the block to the bin.

How can I tell if a block is read-only?

Unfortunately, read-only blocks are not visually distinguishable from any other block. Typically, blocks that are pre-filled in the code editor will be marked read-only in some way.

Why do we use read-only blocks?

Read-only blocks are used to provide more scaffolding to students and to help them get started. 

Read-only blocks are always blocks that are required as part of the solution.They don’t need to be separated, edited or deleted to solve the problem.

What if a student manages to delete or change a read-only block?