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Orig. question: I want to write a function in pure javascript which uses the Jquery-like selector with :eq(0) declarations, let's say eg to iterate trough a table like
$('tr:eq(8) > td:eq(13)').val();
For this I am trying to write a regex and I stuck here
var str = "I don't want +5+ and not 10 or [12] nor (120) but :eq(5) and :eq(120)";
var matches = str.match(/\:eq\(\d+(\d{1,2})\)?/g);
console.log('matches: '+matches);
which returns only matches: :eq(120)
but not matches: :eq(5),:eq(120)
as wanted. What can I do here ?
You can simplify your regex:
var str = "I don't want +5+ and not 10 or [12] nor (120) but :eq(5) and :eq(120)"; const matches = str.match(/:eq\\(\\d+\\)/g); console.log('matches: '+matches);
UPDATE SUCCESS / RESULTS to share my toughts:
I have a table
<table>
<tr>
<td><span>1</span></td>
<td><span id="span2">2</span></td>
<td><span>3</span></td>
<td><span>4</span></td>
</tr>
<tr>
<td><span>5</span></td>
<td><span>6</span></td>
<td><span>7</span></td>
<td><span>8</span></td>
</tr>
</table>
and using the previous answers I wrote this small script, which is the beginning of a simple selector engine.
const ltrim = (haystack, needle) => {
var regex = new RegExp('^'+needle);
return haystack.replace(regex, '');
}
const rtrim = (haystack, needle) => {
var regex = new RegExp(needle+'$');
return haystack.replace(regex, '');
}
const $ = (s) => {
var el = document;
if (!s.match(/:eq/g)) {
var cut_index = Math.max(s.lastIndexOf('>'),s.lastIndexOf(' '))+1;
var last = s.substring(cut_index);
if (/#/.test(last)) el = el.querySelector(s);
else el = el.querySelectorAll(s);
}
else {
var m = s.match(/:eq\(\d+\)/g);
var p = s.split(/:eq\(\d+\)/g);
for (i in p) {
if (p[i] == '') i++;
else {
if (i == p.length-1) {
if (p[i].match(/#/)) el = el.querySelector(p[i]);
else el = el.querySelectorAll(p[i]);
}
else el = el.querySelectorAll(p[i])[m[i].match(/\d+/g)];
}
}
}
return el;
}
Now I can iterate trough the table using jquery-like selector syntax with
alert($('table tr td span#span2').innerHTML); // 2
alert($('table tr:eq(1) td:eq(1) span:eq(0)').innerHTML); // 6
alert($('table tr:eq(1) td:eq(2) span')[0].innerHTML); // 7
and I am happy for now. This expression, eg
$('table tr:eq(1) td span').forEach(elem => {elem.classList.add('yellow')});
uses regular JS syntax to highlight a complete row, or just one cell:
$('table tr:eq(1) td span:eq(2)').classList.add('yellow');
I'm not sure about the support of other jquery-like css selectors, will see in the future. In case of improvements further updates will be here.
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