Fix for .data() method to read scientific notation as string as is.

[jasongodev]

Problem

<div class="data-scientific" data-unsigned="1234e5" data-epositive="1234e+5" data-enegative="1234e-5"></div>

// This is true
jQuery('.data-scientific').data('unsigned') === '1234e5';

// This is false, because cash will return 123400000 due to JSON.parse('1234e5') parses it to a number.
cash('.data-scientific').data('unsigned') === '1234e5';

Solution

• test for scientific notation using regex, if true then return value and do not JSON.parse'd it

[fabiospampinato]

1. Can you delete all the dist and unnecessary changes from this PR?
2. Looking at the code shouldn't this be working already? Like JSON.parse ( '1e99' ) is parsed correctly for me, is the string not reaching JSON.parse for some reason?

[jasongodev]

Hi Fabio, JSON.parse will convert the '1e99' into a number. What we want for .data() is to return '1e99' as '1e99' and not as 1000000000. So before we pass the string to JSON.parse, we need to check if it has a scientific notation format. This is consistent with jQuery, Zepto, and native Element.dataset.get() routine.

I will revert the dist and other edits from this pull request.

Thanks!

[fabiospampinato]

Thank you but our data function is explicitly not fully aligned with jQuery, as jQuery's implementation doesn't work with stuff like React, which some people, me included, use alongside more direct DOM manipulation libraries.

Moreover if there's a data-foo="123"attribute somewhere jQuery's data function will read that as a 123 number, so not reading things like 1e10 as a number too seems inconsistent to me, this should probably be something jQuery should change, not the other way around.

[jasongodev]

I respect your decision on this.

Regarding jQuery and Element.dataset, they probably based it on HTML Spec from WHATWG, where values of dataset properties are returned as DOMString.

https://html.spec.whatwg.org/multipage/dom.html#domstringmap
https://webidl.spec.whatwg.org/#idl-DOMString

Still, cash-dom's .data() method might be a more practical implementation in real world case than it is to follow the specs strictly.

Thank you for your review and have a nice day!

[fabiospampinato]

You might consider using the attr method if what you want is always a string. Potentially you could also override Cash's data method. Unfortunately the best way to write such function isn't obvious, there are pros and cons of both approaches.

Sorry for the inconvenience.