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Over on the nexus-scripting thread on the discord server, Steve asked about modifying the room items tab to add additional functions to the prop items there to enable cover functions -- ie take cover, shoulderroll if you are Scoundrel, cover destruction and the like.  This is in fact possible, but it's beyond my abilities for the moment. I said that it would be easier to assign cover items to the bottom buttons. And then, because I was curious, I tried it out to see if I could make it work.  I'm still not done with it, but I've made a start, and I've learned a ton about how various things work. I thought I'd go through and go over it.  Fair warning- this is going to go on and on, and I'll have to break it up into several posts- hence making it it's own thread rather than hijacking Nexus Miniscripts or something.

So step one. Can I get a list of cover in the room I'm in?  Answer- kinda.  So when you enter a room, or look around you get a GMCP message.  That's Generic Mud Communication Protocol, and it's what the game uses to send data to clients in the background. You normally don't see it, but you can check a box in the Advanced Tab in the client settings to toggle them on. You can see a list of what IRE uses GMCP for here: https://nexus.ironrealms.com/GMCP

So there are three messages we want to look at to deal with cover items:

Char.Items.List

Char.Items.Add

Char.Items.Remove

The first lists all the items in the location, which can be a container, your inventory or the room.

The second two deal with items added or removed from a location. It turns out there are some problems with using these second two for our purposes, but we'll come back to that later. The first one looks like this:

That's a lot of stuff! Let's look a little closer. So the GMCP method is Char.Items.List. The pieces of that are args (short for arguments) the name used for it is args.gmcp_args  Since it's a javascript object you use dot notation to get the pieces. So args.gmcp_args.location is "room". That's what we want, so that's what we are going to look for. The next piece is args.gmcp_args.items  You can see it's surrounded by square brackets [] which means it's an array - essentially a list of things accessed by number: item 0, item 1, etc. Inside that each item in the list is surrounded with curly brackets {}, which means it's an object. Objects, among other things, have named properties. So each item in the list has an id, name and in some cases an attrib.

(If you are already lost because you are unsure what arrays and object are, go here:  https://www.w3schools.com/js/js_arrays.asp , https://www.w3schools.com/js/js_objects.asp)

So, how do I capture that list?  Nexus provides the onGMCP function which will fire anytime a GMCP message is received by the client. In fact you can make as many onGMCP functions as you want and put them in different packages, and they will all trigger. Use caution that you know what each of them is doing if you chose to operate this way. For this, because I want to share, I made a shiny new "Cover" package and gave it it's very own onGMCP function, the first part of which looks like this:

So lets go through that. If the method is "Char.Items.List" do what's in the brackets. Otherwise do nothing.

On the second line we ask if args.gmcp_args is "room". Again, do what's inside the curly brackets, or do nothing.

The third line we create an empty object to hold the cover items. Poetic is the object that I'm using for my system. So we've made another object inside of that. The reason (one of them) to use objects like this is that if you define an object in a script somewhere, it's available in any script you want to use it in.

The fourth line we set a roomitems variable equal to the item list we get from GMCP. This is to make it a little more readable, and so we can use the room item list elsewhere if we want.

The fifth line gets the keys to the items in the object, so that we can iterate over them.

If we ask for args.gmcp_args.location we get "room". What happens when we ask for args.gmcp_args.items?  We get "objectObject" for each of the things in the list.  Hence the bit on the 6th line where it asks "forEach"  So for each item in the array, do this.  (I'll be honest, even though I know why it does it the objectObject response makes me crazy).

The next line is commented out.  // is a javacript comment. You can use it to clarify what you are doing (which I should have more of in there) or to keep code from running. In Nexus client.print displays text on the screen- in this case so I could see what I was getting for debugging purposes.

The following line is an if statement:  if (!poetic.roomitems[item].attrib){

Remember we mentioned above that some items have attributes(attrib)? As far as I know, none of the props have attributes. The ! At the beginning is a negative statement. It says, in effect, "if the item does not have an attribute, continue". 

Everybody still with me? I told you this was going to be long.

We'll gloss over the next lines a little. So we are sorting the items as they come in to see if they could potentially be cover. Things with attributes are out. Things that include "stuffed and preserved" are out. That gets us down to things that are pretty certain to be props. But not all props are cover. So I have an array of things that are "notcover". I don't have the whole list yet, cause I haven't tested every single thing. There are probably a few things that could be sorted out like the trophies. For now, when I get the "you can't cover behind that" message I grab the item name and add it to the array. After I try flipping it. Just for more fun- some things are only cover if you flip them. To make it extra confusing- some things you can flip, but they aren't cover no matter which position they are in. Some things are climbable, and I haven't done much with that at all yet, though I'm trying to build a list.

Once we have them sorted, and we are pretty sure they are cover, we add them to the cover object:

We set a variable again, to make things a little easier to read. roomitem is the entry in the array we get from the forEach statement- poetic.roomitems[item] where item is a numbered entry in the array.

For each of those we make a new entry in poetic.cover with the key set to the item ID number roomitem.id   We use bracket notation there, because you cannot use a variable to access object properties via dot notation. poetic.roomitems.item will fail because it wants an entry literally named "item".

So each item that passes our test becomes poetic.cover[cover item ID#]  That way we can ask for them later by item ID number and not have to search or sort.  For each of those things we store an object that contains the id number, the name, and button 1. The button is just a placeholder, we'll set the button numbers in the next bit.

That's pretty much that. Now we have a mostly correct list of things that are cover. Next up- bend the buttons to our will!