6.2.1. Anatomy of Scripts
6.2.2. Script Types
As mentioned before, scripts are triggered, while functions are explicitly called. Scripts have to be bound to a block, entity, ground, or area in order to function. A script can be triggered by walking over a block, interacting with an entity, entering an area, or interacting with a block.
Each of these triggers come with a type.
interact
The interact script type triggers when the player interacts with a block (stone, button, or anything else). There is no vanilla counterpart to this, except triggering a button or causing a block update.
The interact script type is often used for passwords, submit buttons, NPC (wool-type) dialogue, and much more.
walk
The walk script type triggers when the player walks over the block containing the script. If the script was bound to a block that is now removed, the script still triggers when the player is in the space just above the block.
The walk script type is often used for traps, story elements, resets, and much more.
ground
The ground script type triggers only when the player walks over the block containing the script. It only triggers once the player is on the block, and not while jumping over it, or when the block is air.
The ground script type can be used for crumbling pathways and other effects that require the player to stand on the block.
entity
The entity script type triggers when a player interacts with an entity. The script gets removed once the entity dies or despawns. When a script is applied to an entity, the server tries its best to keep the entity from despawning, but sometimes the inevitable occurs. Therefore, be prepared to respawn the entity with all scripts in place (by for example creating a function that correctly restores the entity may it be missing, and calling it whenever the entity is needed).
The entity script type is often used for dialogue.
area
The area script type is a new script type in MSC 2.0, triggering a script once when a player enters the set area.
function
To create content in a function, the function type is used. A function is always explicitly called from a script or other function. When adding script lines to a function, the function has to be defined using the function command. See Function Commands for details on defining a function
6.2.3. Lines
Every script consists of script lines, which are the actual content of the script. Each line is prefixed with the Script Operator, described in Script Operators. The Script Operator takes parameters that make up the rest of the script line.
A script is executed from top to bottom, waiting, delaying and executing commands as necessary. A script may not execute fully when a @return operator is used. @return cancels the script upon being run, halting further execution. Any resets should therefore always be done before the script terminates.
Once a script starts, a local namespace is created. In this namespace temporary variables can be declared using @define. Since the script executes from top to bottom, the script cannot use a variable before it is defined. The local namespace of the script always overrides the global namespace. Even if a used namespace contains a variable of the same name as the local namespace, the variable in the local namespace will always be used, unless a namespace specifier is used (::).
Once the script ends (due to a @return, expired @prompt or the end of the script), the local namespace is deleted, including any variables stored in it.
6.2.4. Parameters
Alongside default types and variables, a script can also contain parameters. Script Parameters are set by the ’system’. Parameters can be accessed much like any other variable.
A script can have the following basic parameters (situationally, use /s v type to see which ones are present):
player
A Player type. Represents the player executing the script. Is not present within functions.
block
A Block type. Represents the block the script is bound to (if any). Is not present within functions, entity scripts or area scripts.
entity
An Entity type. Represents the entity the script is bound to (if any). Is only present in entity scripts.