BMI Calculator

[HSteacher]

Greetings,
I'm a high school teacher and I just worked through the BMI Calculator interactive tutorial but I'm having a problem. In the stack script I have the following code. When I go into the run mode, enter a height and weight, then click Calculate, I get the following error.

stack "BMI Calculator": execution error at line 7 (LCB Error in file json.lcb at line 65: syntax error: 1:0 unexpected end of input)

System info:
2012 iMac, Mac OS 10.14
LiveCode Community Plus 9.0.3

Any help is appreciated!
P.S. I replaced the period in the URL because the forum gave me the message "You can’t post image, email or url links. Please remove clinicalcalculator<dot>org". Even though I checked the "Do not automatically parse URLs" option

Code: Select all

function getBMI pHeight, pWeight
   put "http://api.clinicalcalculator<dot>org/bmi?" & \ 
         "height_in_m=" & pHeight & "&weight_in_kg=" & pWeight into tURL
   
   put url tURL into tJSON
   
   put JsonImport(tJSON) into tArray
   return round(tArray["result"]["value"])
end getBMI

[Klaus]

Hi HSteacher,

obvously the server involved in that example does not exist anymore!?
Therefore we get nothing in tJSON and obviously the "json.lcb" widget
does not like it and gives this error.

You need to have at least 10 postings before you can post links etc.


Best

Klaus

[dunbarx]

Hi.

Welcome.

I would roll my own BMI calculator. It is a perfect starter project. You will get all the help you need right here.

Start with a new stack, one button and one field. Make it pretty later.

Craig Newman

[mrcoollion]

I agree with Craig ,

Here is the BMI formula. Have fun.....

BMI_Formula.png (3.07 KiB) Viewed 5849 times

[FourthWorld]

1. The formula is easy enough that you'll deliver a a better user experience calculating it locally, as Craig suggested.

2. As an exercise in API usage, it's useful for diagnostic practice. What happens when you try the URL in a browser?

[Klaus]

When I tried/try this in a browser, Safari tells me that is cannot find the server.
That why i presumed the server to be down (or at least currently not available).

[bogs]

Considering this tutorial is included in the IDE, I wonder if the problem should be reported as a bug.
*Edit - Elanor beat me to it
https://quality.livecode.com/show_bug.cgi?id=20572

She also posted the work around code -

As a workaround to make the current stack work the getBMI function on the Stack Script can be replaced by

function getBMI pHeight, pWeight
return round((pWeight/pHeight)/pHeight)
end getBMI

2. As an exercise in API usage, it's useful for diagnostic practice. What happens when you try the URL in a browser?

It may be useful for diagnostic practice IF it were expected to not be working AND the tutorial informed you of that.

I think it far less useful for someone picking up the language as a new language, following what you would expect to be a working tutorial, and then coming upon the error with no explanation why.

I would think that would actually be very un-useful and probably confusing, or at the least very annoying and irritating to the new comer.

[Klaus]

Wonderful, so this is a known bug since october 2017!
Very encouraging for newcomers.

[MaxV]

I agree with Craig ,

Here is the BMI formula. Have fun.....

BMI_Formula.png

Yes, so the code would be:
########CODE to copy and paste with your mouse#######
function getBMI pHeight, pWeight
#if pHeight is in cm, then
put pHeight / 100 into pHeight
put pWeight / ((pHeight)^2) into temp
return round ( temp)
end getBMI
########END OF CODE generated by this livecode app: http://tinyurl.com/j8xf3xq ########
########Code tested with livecode 9.0.4-rc-2########