Want to learn coding: programming an ApplyDamage button

Hi! I am new to Roll20 (playing DnD5e) and new to javascript as well. But I can learn best if I have a specific task in mind .... I have added actions for my NPCs/creatures for attacking (I think like those added with TokenAction), plus a reference to a target. Now, if my creatures attack  player it is written into the journal (attack rolls, damage, and target of attack). What I want to have is a script that captures such a message and adds a button below that message, 'apply damage'. I am well aware of dozens of cases where such damage shouldn't be applied automatically, but most combats are standard combats. So I am satisfied to 'manually' decide if the situation is a standard situation and save a lot of time when applying the damage to the targeted player. It would be great if players could hit such a button also, so that I don't have to change hps of my monsters by myself. I really think this could save a lot of time. I am looking through the codes of applydamage.js for example, and I think I can figure out how to do this from here, _if_ the functionality of such a button is possible at all. So my question is: Is this possible or are there any severe problems to solve? In the forum this idea has been mentioned several times, but I didn't find a finished script :-) Best  regards, Norman

I am not sure you would need to write a new script. There are already scripts that can do some of what you wish, such as chatsetattr and TokenMod. Since you are creating macros you could create a global macro and tie it to an ability button in your macro to put into chat. 

True, and I use those scripts already and had planed to use them exactly as you suggest. ;-) But I want to have the button, or something similar, enabling me to choose between easy hitpoints reduction or not. I don't have a clue, how to 'feed' the button function with the correct information (target and damage). Maybe this is much easier than I thought ..?  I need to register an event, looking for some specific words in the chat, extract the needed information, then set up the button calling TokenMod with those information and I am done. That is the way to accomplish my little project, right?

I&nbsp; am not sure about how to do it in an API directly, but if you simply calling another api command you can put that into button via [label](ability/macro)&nbsp;&nbsp; <a href="https://roll20.zendesk.com/hc/en-us/articles/360037256754-API-Chat#API:Chat-sendChat(speakingAs,input[,callback[,options]])" rel="nofollow">https://roll20.zendesk.com/hc/en-us/articles/360037256754-API-Chat#API:Chat-sendChat(speakingAs,input[,callback[,options]])</a> &nbsp;and&nbsp;<a href="https://roll20.zendesk.com/hc/en-us/articles/360037256794#Macros-MoreExamples" rel="nofollow">https://roll20.zendesk.com/hc/en-us/articles/360037256794#Macros-MoreExamples</a>

So, there are a couple pieces you need to handle in the above, none of them too difficult. First off, the capturing of the message.&nbsp; You just need a handler for the "chat:message" event which then outputs your message.&nbsp; Here's a very simple example that responds to someone mentioning the word "taco": on('ready',()=&gt;{ on('chat:message', msg =&gt; { if(msg.playerid !== 'api' &amp;&amp; /taco/i.test(msg.content)){ sendChat('API',`(Did someone mention tacos?)`); } }); }); One thing to be aware of: you can very easily end up in an infinite loop if you aren't careful.&nbsp; If you take out the check against the playerid being the API, this will result in an infinite number of chat messages about mentioning tacos.&nbsp; If you get in that situation, disable your script then go clear your chat log outside the game. Secondly, outputting a button.&nbsp; This is really straight forward and well documented here:&nbsp; <a href="https://wiki.roll20.net/API:Chat#API_Command_Buttons" rel="nofollow">https://wiki.roll20.net/API:Chat#API_Command_Buttons</a> Basically, you're just outputting either a Markdown format button: sendChat('Do a thing',`[Do it](!do-something with args)`); Or an HTML anchor tag with the href set to the command: sendChat('Do a thing',`&lt;a href="!do-something with args"&gt;Do it&lt;/a&gt;`); The benefit of a HTML anchor tag is the ability to style it as something other than a big pink button.

Uh, looks much easier than I thought. Must try it immediately .... after taking a good nights sleep first :-) Thank you!

The scriptomancer to the rescue...lol

@Norman V.&nbsp; You can also check this script that @Jacob did some time ago:&nbsp;&nbsp; <a href="https://app.roll20.net/forum/post/3631602/script-groupcheck-roll-checks-saves-et-cetera-for-many-tokens-at-once/?pageforid=4359153#post-4359153" rel="nofollow">https://app.roll20.net/forum/post/3631602/script-groupcheck-roll-checks-saves-et-cetera-for-many-tokens-at-once/?pageforid=4359153#post-4359153</a> .

Thank you, Mark W., that was the post I had seen a while ago. Before I thought about scripting at all :-) Didn't find it again, though ... I wasn't sure it was almost exactly what I am looking for now :-) So, now I will try coding my button :-)

There's one thing (at least for now :-) ) I don't understand: I extract the different kinds of damage from the rolltemplate-message, adding dmg1 and dmg2, and also add the crits damage, but is there any flag to decide if that was a crit at all? Is this information not included in the message.content? Or am I just blind to see it? I began to circumvent this by evaluating the original rolls, but can't finish it right now.

Hi Norman. Did you happen to make any progress on this at all? It seems a rather useful feature.

Hi Ryan G.! Yes, I did make some progress. Actually up to that it is useful for me :-) The next step would require much more work .... and maybe it's not realistic to achieve at all: There are so many special conditions to consider. But still, I can use the "apply damage" button in about 75% of all times, although sometimes the damage is calculated wrong. I think it has to do with 2nd kind of damage and the way I set it up (e.g. sneak damage). But I can live with that; it still saves time! When I am returning to my computer I hope to remember to send the code. But it is mainly based on code from other people. I also changed ApplyDamage.js in some minor ways. I can't create a list of changes out of my head now, but I think it was only for displaying reasons. By the way: Thanks for all the input, players!

You might also get some use out of this script I wrote awhile back:&nbsp; <a href="https://app.roll20.net/forum/post/8469386/script-5e-automatic-attack-script-compares-roll-to-target-ac-and-deducts-damage/?pageforid=8469386#post-8469386" rel="nofollow">https://app.roll20.net/forum/post/8469386/script-5e-automatic-attack-script-compares-roll-to-target-ac-and-deducts-damage/?pageforid=8469386#post-8469386</a> .&nbsp; No "apply damage" button, it just automatically subtracts. If nothing else it might give you some ideas,&nbsp;

Thank you for this useful info.