precision: 0; not working?

[Coernel82]

Hi, I tried to get rid after the digits after the comma, so instead of 89,32 just 89 - this seems to fail. I also tried precision: 5; which correctly resulted in 89,32000

Can you confirm that there is a bug?

[ralberth]

Hi! What did you try to get rid of the digits after the comma? For example, do you have the table definition, or the section of your config.js with the MMM-MysqlQuery set up? I'm wondering if you used precision: 0 and are seeing trouble.

As a stop-gap, you could consider logic in your SQL SELECT that prepares the data the way you want it to display, such as "select format(num_col, 0) from mytablename".

[Coernel82]

Yes, precision: 0 is causing the trouble:

{
            module: 'MMM-MysqlQuery',
            position: "bottom_center",
            config: {
                connection: {
                    host: "localhost",
                    port: 3306,
                    user: "zisterne",
                    password: "zisterne",
                    database: "RASPBERRY_PI",
                },
                query: `select level from zisterne order by id desc limit 1`,
                intervalSeconds: 15 * 60,
                emptyMessage: "Kein Füllstand",
                columns: [
                    { name: "level", title: " ", precision: 0,  cssClass: "zisterne", suffix: "%"},
                ]
            }
        },

Thank you for the sql hack but I am not sure how to implement. I also found SELECT ROUND(x,y) So would it be select round(level,0) from zisterne order by id desc limit 1 ?

[ralberth]

For now, yes you can use

query: `select format(level, 0) as level from zisterne order by id desc limit 1`,

as a temporary solution.

---

I tried precision: 0 with different data-types and values, and I can confirm it's a bug!

Here's some developer junk:

Setting a precision in config.js just causes the number toFixed() function to be called. This behaves like you think it would:

❯ node
Welcome to Node.js v16.13.0.
Type ".help" for more information.
> let a = 123.456;
undefined
> a.toFixed(0)
'123'
> a.toFixed(1)
'123.5'
> a.toFixed(2)
'123.46'

The code in question from MMM-MysqlQuery: https://github.com/ralberth/MMM-MysqlQuery/blob/master/MMM-MysqlQuery.js#L172-L174

When I tried it out, all values for precision worked as expected, but using 0 didn't. 0 just skips this "if". This is a crappy JavaScript thing: zero is "falsy", meaning it fails an IF statement. The fix is to change if (cellConf.precision) to if (cellConf.precision == null). I'll put in the change and test it soon.

[Coernel82]

Thank you for the explanation - I understand that and indeed that is crappy. A little anecdote from our German tax program ELSTER: In the past more ore less randomly the tax forms wanted to have a 0 for empty vaules and in other form fields just blank space and no 0 . You had to figure that out by trial and error.

[ralberth]

Fixed in commit https://github.com/ralberth/MMM-MysqlQuery/commit/c1e79c5b0033fdac25923fffbb0f24fc06f49569

Please do a git pull in your modules/MMM-MysqlQuery to pick-up the change, and restart your MagicMirror server. Let me know how it goes and if you're happy, we'll resolve this ticket.

[Coernel82]

Sorry, I missed to replay. I can confirm that it is fixed. Thank you for your great efforts!