The modern one does not work (I used Google Chrome and Microsoft Edge, both failed)
The classic one works.
Meanwhile, one more question:
Before I got your help, I got around the problem by using an "each" loop, as follow:
$(e.target).find("tr").each(function (idx, myElem) {
if ($(myElem).attr("class") == pid) {
myTr = myElem; break; // this break causes failure
}
});
I used "break" above because I was interested only in the first occurance. But the "break" caused failure that the rest of the code (not shown) was not executed.
Why?
But the "break" caused failure that the rest of the code (not shown) was not executed.
The break statement exits a switch statement or a loop (for, for ... in, while, do ... while), if you want to excute the first occurance, you can try to use "return" instead of break.
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the .each() is making a function call. jQuery added break support it:
$(e.target).find("tr").each(function (idx, myElem) {
if ($(myElem).attr("class") == pid) {
myTr = myElem;
return false; // this will break the .each() loop
}
});
your code is much slower than passing the computed string to jquery, because jquery can use the browsers built-in document.querySelector(). also if you are only interested in the first match, you should add to the query (so it can do the break on first match):
var q = $(e.target).find("tr[class=" + prodId +"]:first");
note: chrome, firefox & safari supports javascript template strings. you probably did not use the backquote:
var p1 = "hello";
var p2 = "jon";
var s = `${p1} ${p2}`; // "hello john"
You are right that "break" can't break out of "each" loop.
(However, I can't use "return" here because I still need to execute the remaining statements following the "each" loop)
Member
19 Points
66 Posts
Specifying attribute name matching a variable does not work
Nov 19, 2019 11:11 PM|GoldenMicrosoft|LINK
Hi everyone,
The following does not work: $(e.target).find("tr[class=prodId]"); where prodId = "P123", for example.
However, when I use a literal in place of a variable, e.g., $(e.target).find("tr[class='P123']"); works.
My question is: is there anyway to find an HTML element, such as 'tr' in the above example, whose attribute value equal to a given variable?
Thanks,
Golden
All-Star
58214 Points
15668 Posts
Re: Specifying attribute name matching a variable does not work
Nov 19, 2019 11:16 PM|bruce (sqlwork.com)|LINK
in moderen javascript its:
$(e.target).find(`tr[class=${prodId}]`);
in classic its:
$(e.target).find("tr[class=" + prodId +"]");
Member
19 Points
66 Posts
Re: Specifying attribute name matching a variable does not work
Nov 20, 2019 03:00 AM|GoldenMicrosoft|LINK
Hi Bruce,
Thanks so much for your help.
I tested both ways:
The modern one does not work (I used Google Chrome and Microsoft Edge, both failed)
The classic one works.
Meanwhile, one more question:
Before I got your help, I got around the problem by using an "each" loop, as follow:
$(e.target).find("tr").each(function (idx, myElem) {
if ($(myElem).attr("class") == pid) {
myTr = myElem;
break; // this break causes failure
}
});
I used "break" above because I was interested only in the first occurance. But the "break" caused failure that the rest of the code (not shown) was not executed.
Why?
Thanks again,
Golden
Contributor
3370 Points
1409 Posts
Re: Specifying attribute name matching a variable does not work
Nov 20, 2019 10:39 AM|samwu|LINK
Hi GoldenMicrosoft,
The break statement exits a switch statement or a loop (for, for ... in, while, do ... while), if you want to excute the first occurance, you can try to use "return" instead of break.
More information about the use of break you can refer to this link: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Statements/break
Best regards,
Sam
All-Star
58214 Points
15668 Posts
Re: Specifying attribute name matching a variable does not work
Nov 20, 2019 06:16 PM|bruce (sqlwork.com)|LINK
the .each() is making a function call. jQuery added break support it:
$(e.target).find("tr").each(function (idx, myElem) { if ($(myElem).attr("class") == pid) { myTr = myElem; return false; // this will break the .each() loop } });your code is much slower than passing the computed string to jquery, because jquery can use the browsers built-in document.querySelector(). also if you are only interested in the first match, you should add to the query (so it can do the break on first match):
var q = $(e.target).find("tr[class=" + prodId +"]:first");
note: chrome, firefox & safari supports javascript template strings. you probably did not use the backquote:
var p1 = "hello";
var p2 = "jon";
var s = `${p1} ${p2}`; // "hello john"
Member
19 Points
66 Posts
Re: Specifying attribute name matching a variable does not work
Nov 20, 2019 11:04 PM|GoldenMicrosoft|LINK
Hi Sam,
Thanks for your reply.
You are right that "break" can't break out of "each" loop.
(However, I can't use "return" here because I still need to execute the remaining statements following the "each" loop)
Best Regards,
Golden
Member
19 Points
66 Posts
Re: Specifying attribute name matching a variable does not work
Nov 20, 2019 11:16 PM|GoldenMicrosoft|LINK
Hi Bruce,
Your reply puts the great versatility of jQuery in great display!
Yesterday I took the backquote as a single quote, othewise everything works according to what you said.
Thanks so much for your great help,
Golden