Reactor-Editor / Reactor-ui-Status Errors

[LibraSun]

WILCO, just bear with me while I endure the "two steps back" phase of debugging my workflow, and get back to you.
For the moment, I suspect the problem is me, not MSR.

[LibraSun]

@toggledbits I'm noticing that in MSR the following boolean test expressions are equating to FALSE when I naively expect TRUE (at least for the array version): 1 in {one:1} and 1 in [1,2,3]

Also FALSE for: "one" in keys(testobj) where testobj := {one:1,two:2,three:3} which MSR sees internally as {"one":1, "two":2, "three":3}

More importantly, despite in being declared a reserved keyword in lexpjs, it is not (yet) explicitly included in your docs among the array operations. Should I submit a request for that?

Thanks for your insights, as always.

EDIT: Think I found the answer to where "in" belongs in the lexpjs docs... it's intended for the each..<item>..in..<array> construct, whereas the docs currently describe each..<item>..OF..<array> so please accept this typo submission.

I believe this means I should not be attempting to use in as I described above, then? And always use indexOf() instead?

[toggledbits]

@librasun said in Expressions and LuaXP Functions:

1 in {one:1}

This is false because 1 is not a key of the object.

1 in [1,2,3]

Is actually true (just tested in lexpjs) because 1 is a key in the object (i.e. the element at array index 1 exists). This is JavaScript semantics.

Also FALSE for: "one" in keys(testobj)

That would be correct because, following those JavaScript semantics, keys() returns an array, and one is not a valid index for any array.

Now, we can talk about whether or not the array behavior is expected. The smart folks that came up with JavaScript think so, but that doesn't mean it's the right answer for Reactor. It never occurred to me to use in on array in JavaScript, so I've never seen this effect; the "correct" way is (among several) Array.find() or Array.indexOf(). There is an indexOf() function in MSR/lexpjs.

On the 1 in { 'one': 1 } being false, though, this is defensibly correct in both Reactor and JavaScript. If we change the behavior of in for arrays, then test (and true result) you want here would be written as 1 in values( { 'one': 1 } )

[LibraSun]

I see. I hadn't considered the .find method only because it wasn't explicitly mentioned in lexpjs docs, but should have assumed it present from JS by extension.

Furthermore, I stand corrected about 1 in [1,2,3] which I swore (should not!) MSR returned as FALSE on first run of test. My bad.

Lastly, where do you stand on [1,2,3] || [3,4,5] and [1,2,3] && [3,4,5]? Former is returning TRUE (sorta expected) and latter is returning [3,4,5] which I kinda get, but don't?

[toggledbits]

@librasun said in Expressions and LuaXP Functions:

I see. I hadn't considered the .find method only because it wasn't explicitly mentioned in lexpjs docs, but should have assumed it present from JS by extension.

[referring to Array.find()] That's not a lexpjs function, it's how you do what you are trying to do in JavaScript (find a value in an array). Your Reactor/lexpjs solution is indexOf(). Also note that dot-function notation is not supported by Reactor/lexpjs -- you can't say somearrayname.indexOf( lookingfor ), you have to write indexof( somearrayname, lookingfor ).

I'm tempted to just leave in as-is for arrays, but well-documented, simply because it follows a common-use language pattern, and there is a defined replacement, which happens to be (almost) the same for both.

Lastly, where do you stand on [1,2,3] || [3,4,5] and [1,2,3] && [3,4,5]?

That's a bug. The answer for the former should be [1,2,3] and for the latter [4,5,6]. Fixing now.

[LibraSun]

MSR SAMPLE EXPRESSIONS: Timestamp

If you want to display a timestamp in a stored variable or an outbound message from MSR, that looks like "14:24:43 Wed 2021-Mar-17", allow me to save you some typing. Just include this Expression in your Reaction, and reference ${{timeStamp}} in your workflow.

daysList = ["Sun","Mon","Tue","Wed","Thu","Fri","Sat"],
monthsList = ["","Jan","Feb","Mar","Apr","Jun","Jul","Aug","Sep","Oct","Nov","Dec"],
timeNow = dateparts(time()),
timeStamp = timeNow.hour + ':' + substr('0' + timeNow.minute,-2,2) + ':' + substr('0' + timeNow.second,-2,2) + '  ' + daysList[timeNow.weekday] + ' ' + timeNow.year + '-' + monthsList[timeNow.month] + '-' + substr('0' + timeNow.day,-2,2)

This construct takes advantage of the multi-statement feature built into MSR, which permits you to string together a series of declarations and evaluations within a single Expression. I've also sprinkled in a little formatting spice, so that single-digit day, minute and second fields display with a leading 0.

[toggledbits]

lexpjs is missing some functions that LuaXP had and range from convenience to vital. Seems that date/time formatting is among them, as this should be a simpler operation, and we can take advantage of all the localization that the system itself offers in the process.

Among the functions I know are missing, or I'm pondering, are:

format( template, ...args ) - A C-style formatter for strings (like sprintf())
strftime( template, time ) - Also C-style, formatting specifically for date parts.
dateadd( time, yy, mm, dd, hh, MM, ss ) - Modify a timestamp; e.g. dateadd( time(), null, null, 1 ) would add one day to the current time (so the result time would have the same hour, minute, second just a day forward)
dateset( time, yy, mm, dd, hh, MM, ss ) - Another way to modify a timestamp, e.g. dateset( time(), null, null, null, 0, 0, 0 ) would result in midnight for the current date, while dateset( time(), null, null, null, 24, 0, 0 ) would be exactly midnight tomorrow.
push, pop, shift and unshift - Array functions to move an element in or out.
concat - Concatenate two arrays; function, or overload + ( e.g. [1,2,3] + [4,5,6] => [1,2,3,4,5,6] )
slice - Return a portion of arrray; pondering whether this should be done as a function, or with python-style array[start:end] syntax (into the whole brevity thing);
splice - Remove elements from, and insert into, and array; splice() is the JavaScript function, and it's very powerful but not particularly user-friendly. Maybe better to have separate remove() and insert() ?

The HubitatController also extends lexpjs with its own private hsltorgb() and rgbtohsl() functions to convert between RGB and HS(L) as part of its entity mappings. I'm considering making these available everywhere (could be useful in some actions in particular on any platform).

You may note that map/reduce functions are missing, but they are covered by the each operator (e.g. each val in numbers: val**2 produces a new array of the square of the values in numbers, the map() function, while t=0, each val in squares: t=t+val is a reduce that produces the sum of the squares); the select() function from LuaXP is covered by the first option (e.g. first element in array-or-object with match-expression). And filtering can also be done with each because any null result during iteration isn't added to the result array.

[LibraSun]

Wonderful!

COMMENTS:

• Yes, brevity counts.
• Did not know LuaXP (much less lexpjs) has exponentiation with **, only knew pow( )
• Hadn't used some of the older syntax much like pop or concat, but other power users sure did
• YES to HSL◄►RGB conversion
• I'm new to each, first and do but gosh are they powerful!

Guess you'll have your hands full deciding which to implement and then fleshing out the lexpjs docs!
Looking forward to it. Thanks again.

[LibraSun]

Does MSR have an equivalent of Reactor's...?

getattribute( DeviceNum ,'name')

Cannot find such an attribute in Expression Builder.

[toggledbits]

No equivalent function, but the name is available as getEntity( .... ).name

[LibraSun]

I'll try that, and encourage you to add that to drop-down.

Also, meanwhile, I'm getting a (null) response with:
getEntity( "vera>device_337" ).attributes.x_vera_device.device_number
which IMHO ought to be (number) 337, no?
EDIT: Solved with a hard refresh of browser! Weird.

[LibraSun]

Is there a way to modify the following such that ALL whitespace gets replaced with the underscore (i.e. make the RegExp a 'global')??

replace(msgText, "\s", "_")

[toggledbits]

I'm going to enhance the following functions to work like this. I use the "old school" *nix notation for optional parameters by enclosing in square brackets, so where you see that below, those parameters are optional.

• match( string, pattern [ , num [ , flags ] ] ) - Find pattern in string. If num is given and the pattern contains regexp groups, the function will return the numth matched group (e.g. match( "The rain in Spain", "r(ai)n", 1 ) returns "ai"; zero is always the full match, and thus the default). If flags is given as "i", a case-insensitive match will be performed.
• find( string, pattern [ , flags ] ) - Returns the position (0-based) of the matched pattern in string. Returns -1 if the pattern is not matched. The flags have the same meaning as in match().
• replace( string, pattern, replacement [ , flags ] ) - Replaces the first occurrence (by default) of pattern in string with replacement. If specified, flags have the same meaning as in match(), plus the additional flag "g" (for global) modifies the behavior to replace all instances of the pattern in string (if needed, multiple flags can simply be concatenated, as in "ig" for case-insensitive + global). The replacement string uses $ as a special pattern lead-in, so $` yields the portion of string before the matched pattern, $' yields the portion of string after the matched pattern, $& is the entire matched substring, $n inserts the match of the nth group in pattern, and $$ yields "$" (self-escape).

Basically, all of this follows JavaScript semantics, which provides the underlying implementation.

[LibraSun]

Will MSR still interpret the literal \n as a line break (equivalent of <br> in HTML) in text strings? Or is it going to be escaped differently (if used at all)?

[toggledbits]

In what context?

[LibraSun]

For example, I like to pre-format the messages I send via SMTP, and routinely define:

msgText := "Hello from Vera. \n\n I see you are running MSR! \n \n Sincerely, Vera"

[toggledbits]

Yes, will happen. It raises priority on another "to-do" item for the parser, which has rather "blunt" string lexing at the moment. I've got a more formal version working now, but I want to play with it a little more before I commit it to MSR.

[LibraSun]

You make it, I break it.

[LibraSun]

@toggledbits I can't seem to concoct a meaningful example of DO .. DONE, since I'm probably not grasping its intended function within the MSR framework.
Does it have a use here, and if so, how would such a statement look? Thanks!

[toggledbits]

do...done is intended to help the first and each statements (but can be used anywhere, really).

1. the each and first statements operate only on a single expression;
2. do...done encapsulates multiple expressions (separated by comma), but looks like a single expression to each and first;
3. The result of a do...done statement is the value of the last expression executed within it.

Here from my own configuration is an example:

each detector in leak_detectors: 
do 
  d=getEntity(detector), 
  d.attributes.arming.state && d.attributes.binary_sensor.state ? d.id : null 
done

There's a separate expression called leak_detectors that provides an array of leak detector entity IDs (canonical, across controllers, of course). The each statement iterates over each of them. The do...done encapsulates two expressions: the fetch of the entity stored to a local variable in the first, and then uses that local variable twice in the second expression. The result of the do...done is the result of the last expression, which is the detector's ID if it is armed and tripped, or null otherwise. With an each expression, any nulls do not appear in the final array.

The idea should be familiar from RFV, although the construction is a little different: it's a loop over a list of known leak detectors and builds an array of those that are armed and in alarm (if any, hopefully not).