Read the statement by Michael Teeuw here.
SmartThings
-
@buzzkc so, with promises, you have a ‘then’, with a ‘resolve’ and an ‘error’ callback, and the resolve and reject methods of the promise can provide data to the resolve and error routines…
just a reminder, the return new Promise() returns IMMEDIATELY… the function inside the promise is called async sometime (milliseconds) later
function_name: function(parm1_in, parm2_in) { return new Promise( function (resolve,reject){ if( all_good) { resolve(data_item) } else { reject(error_data) } } )
then the method CALLING this function
function_name(parm1, parm2).then( resolve_func(data_item){ }, error_func(error_data){} )
a working example , using the arrow function (parm) => {
the arrow function insures that the data context of the outside caller is maintained,
where as function(parm) { does not (u had to use the ‘self =this’ thinglet promise = new Promise(function(resolve, reject) { if(!setTimeout(() => resolve("done!"), 1000)){ reject("settimeout_failed") } }); // resolve runs the first function in .then, reject runs the second function promise.then( // this will block until the function inside the promise call resolve or reject result => alert(result), // shows "done!" after 1 second error => alert(error) // doesn't run .. this will never occurr as settimeout never fails. );
-
Thanks Sam, That does help explain things. The grandkids are visiting, so will be a day or so before I get back to this, unless I just can’t sleep tonight. ;-)
-
@buzzkc no problem… i’ll be around
also, the function in the promise can also be arrow
return new Promise( (resolve,reject) =>{ if( all_good) { resolve(data_item) } else { reject(error_data) } })
-
and you can nest calls to functions that return Promises.
call_function_a(parm1, parm2).then( resolve_function(resolve_parm){ ... processing call function_b(resolve_parm).then(resolve_function(some_otherdata){ .... processing }) })
the 1st call_function_a routine will return a Promise object immediately
and when the function inside the promise resolves, then ‘.then (resolve’ function will be called.the ‘.then’ waits
you can also split it up and wait later
var p = call_function_a(parm1, parm2) processing processing Promise(p).then (... etc)
i have a piece of code that loads a list of images from multiple difference sources, and knowing these take a ‘long time’ I wrapped them in promises… and start multiple at the same time…
now I have a list (array) of promises… but need to wait for all of them to complete (to have the complete list of images)
Promise.all(list).then(() => { sort full list of images, note that resolve() can't send back the list as its not complete }
you can also wait for one
Promise.race(list).then( ... etc)
-
Still working on getting things to refresh, but here is a teaser…
Let me know if the pic isn’t showing or disappears, using google photos
-
@buzzkc looks good
-
I’ll start a new thread for this, but if anyone wants to try it out or PR it, keep in mind, it’s my first module. ;-)
https://github.com/buzzkc/MMM-SmartthingsCurrently I’m only supporting a subset of device capabilities. I can only run one instance of the module also since everything is returned to a global array. More than one instance all the devices from each module instances get put into the array and the full list of devices displays on all instances rather than what was specified for that instance.
For multiple capabilities in the list, the display is sorted by device name, then by capability alphabetically.
It also displays devices for all locations, I’ll see if I can make this selective in the future, but fits my needs as it is.
-
Just stopping in and I wanted to say Thank you guys for working on this! I am still hammered as all get out with work and crawl home most nights… I’m running 3 months behind right now. But I wanted to check in and wow… this is amazing!! Thank you guys so much!
-
Well, looks like it’s duplicating some of the items in the array. I’ll get a patch uploaded for it soon.
Edit: Found this was due to having more than one browser open, each instance was updating the global array. Working on a fix.
-
I’ve fixed the duplication, added an excluded device name list, fixed some timing issues, and cleaned it up.
I’m not entirely happy with the way I’m getting all the data, but I haven’t quite figured out a good way to wait for all the promises returned from the smartthings-node library. I have to loop the capabilities, make a request to get devices by capability, wait for that promise, then loop devices to get the statuses for each, once those promises return I need to pair up the status with its device.
So the ugly of it is that I’m just pushing all the data via sockets for each status request into an array that gets updated, then it gets fed to the getDom(). Not pretty, but it’s working.