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Groups > comp.lang.javascript > #23208
| Message-ID | <1780761.mlrEmVmIzg@PointedEars.de> (permalink) |
|---|---|
| From | Thomas 'PointedEars' Lahn <PointedEars@web.de> |
| Organization | PointedEars Software (PES) |
| Date | 2014-02-22 22:05 +0100 |
| Subject | Re: Get inner text of HMTL element |
| Newsgroups | comp.lang.javascript |
| References | <leambb$nfo$1@dont-email.me> <5308ed02$0$9512$9b4e6d93@newsspool1.arcor-online.net> <leav3t$aa4$5@dont-email.me> <1633562.pVBMJriu5e@PointedEars.de> <leb1q1$r9i$1@dont-email.me> |
Cezary Tomczyk wrote:
> W dniu 2014-02-22 21:11, Thomas 'PointedEars' Lahn pisze:
>> Cezary Tomczyk wrote:
>>> On 2014-02-22 19:31, Martin Honnen wrote:
>>>> Cezary Tomczyk wrote:
>>>>> I would use now:
>>>>>
>>>>> var str = elm.textContent || elm.data || elm.innerText;
>>>>>
>>>>> Is it a good approach?
>>>>
>>>> No, with a browser implementing the W3C DOM Level 3 textContent
>>>> property and an empty element "elm" and no support for the other
>>>> properties you would get the value undefined, see
>>>> http://jsfiddle.net/55euf/, instead of the empty string.
>>>
>>> I've updated the code. How about that?
>>>
>>> http://jsfiddle.net/55euf/1/
>>
>> How about posting it?
>
> No problem. Here we go:
>
> function get_inner_text(elm) {
> var txt = '';
> if (elm && elm.childNodes && elm.childNodes.length > 0) {
> txt = elm.data || elm.textContent || elm.innerText;
> }
> return txt;
> }
Better (but unnecessarily inefficient: consider the “firstChild” property),
but see below.
>>> P.S. I should write first unit tests for it and probably this would
>>> catch scenario which you've described.
>>
>> You do not need a unit test for this, only deeper and clear thinking.
>> What is the result of
>>
>> "" || void 0 || void 0
>>
>> ?
>
> "" is converted to "false" boolean
> void 0 is evaluated to "undefined" and then to "false" boolean
>
> Because all of them are converted to "false" boolean then "undefined" by
> default is returned.
>
> How about that?
The final operand¹ is not converted, and no operand is actually converted
(instead of just internally for the purpose of determining shortcut
evaluation). And nothing is *returned*. Otherwise you have described it
correctly.
> function get_inner_text(elm) {
> var txt = (elm.data || elm.textContent || elm.innerText);
> if (!txt) {
> txt = '';
> }
> return txt;
> }
Much the same could be achieved with
var text = elm.data || elm.textContent || elm.innerText || "";
and it would still be wrong.
For a start, one wonders how you got the idea that an *element* object had a
(built-in, standards-compliant) “data” property to yield the text content of
the represented element.
_______
¹ Colloquially speaking; actually, we are looking at only one “||” operation
whose first operand is the result of another one: “a || b || c” is parsed
like “(a || b) || c” due to the production
| LogicalORExpression(NoIn) :
| LogicalANDExpression(NoIn)
| LogicalORExpression || LogicalANDExpression(NoIn)
<http://ecma-international.org/ecma-262/5.1/#sec-11.11>
--
PointedEars
Twitter: @PointedEars2
Please do not Cc: me. / Bitte keine Kopien per E-Mail.
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Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-22 18:21 +0100
Re: Get inner text of HMTL element Martin Honnen <mahotrash@yahoo.de> - 2014-02-22 19:31 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-22 20:51 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-22 21:11 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-22 21:37 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-22 22:05 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-22 23:38 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-23 10:43 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-23 14:50 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-23 15:48 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-24 21:01 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-24 22:34 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-27 21:41 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-27 22:32 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-28 13:44 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-28 16:54 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-03-04 20:51 +0100
Re: Get inner text of HMTL element ompalompasales2@gmail.com - 2014-03-04 12:59 -0800
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-22 20:59 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-22 22:23 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-22 23:32 +0100
Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-22 21:27 -0300
Re: Get inner text of HMTL element "se" <se@no-one.here> - 2014-02-23 05:35 +0100
Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-23 15:29 -0300
Re: Get inner text of HMTL element "se" <se@no-one.here> - 2014-02-23 21:01 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-23 20:02 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-23 21:55 +0100
Re: Get inner text of HMTL element Cezary Tomczyk <cezary.tomczyk@gmail.com> - 2014-02-24 08:37 +0100
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-24 12:30 +0100
Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-24 15:09 -0300
Re: Get inner text of HMTL element Christoph Michael Becker <cmbecker69@arcor.de> - 2014-02-24 19:43 +0100
Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-24 18:12 -0300
Re: Get inner text of HMTL element Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-02-24 22:51 +0100
Re: Get inner text of HMTL element Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-25 19:49 +0000
Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-26 05:20 -0300
Re: Get inner text of HMTL element "se" <se@no-one.here> - 2014-02-26 17:10 +0100
OT - Re: Get inner text of HMTL element Joao Rodrigues <groups_jr-1@yahoo.com.br> - 2014-02-26 15:48 -0300
Re: OT - Re: Get inner text of HMTL element "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-26 22:43 +0100
Re: OT - Re: Get inner text of HMTL element Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-27 15:00 +0000
Re: OT - Re: Get inner text of HMTL element "Evertjan." <exxjxw.hannivoort@inter.nl.net> - 2014-02-28 10:50 +0100
Re: OT - Re: Get inner text of HMTL element "se" <se@no-one.here> - 2014-02-27 10:57 +0100
Re: Get inner text of HMTL element Dr J R Stockton <reply1400@merlyn.demon.co.uk.invalid> - 2014-02-27 15:46 +0000
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