Node.js puppeteer - How to fetch only certain (filter) records from a table

I'm using node.js and puppeteer to get some data. From the targeted table I only want to fetch certain records though .... . More specific, records with innerText: 'file. ........ .idx'.

The below shows my query:

const tableRows = await page.$$('table > tbody tr');
console.log(tableRows.length);

let tableCell01;
let tableCell01Val;

for (let i=1; i < tableRows.length; i++)

tableRow = tableRows[i];
tableCell01 = await tableRow.$('td:nth-child(1) a');
tableCell01Val = await page.evaluate( tableCell01 => tableCell01.href, tableCell01 );

console.log('n');
console.log(tableCell01Val);




And here the output without the filtering is:

Console:

6

file.20180702.idx
file.20180703.idx
file.20180705.idx
sitemap.20180702.xml
sitemap.20180703.xml
sitemap.20180705.xml


So the desired result should be:

Console:

3

file.20180702.idx
file.20180703.idx
file.20180705.idx


What's the best way to do this? Best would be to filter already before the loop ... to also get the correct tableRows.length

2 Answers
2

You can use page.$x() to check the value of the href attribute with an XPath expression before selecting the rows:

page.$x()

href

const tableRows = await page.$x( '//table/tbody/tr/td[1]/a[starts-with(@href, "file.")]/../..' );


Result:

3

file.20180702.idx
file.20180703.idx
file.20180705.idx


I would use page.$$eval (evaluate a function against an array of elements matched by a selector). This will do all of the required operations in a single call to the browser.

page.$$eval

Pseudocode (assumes that all first-child tds have an a child):

td

a

const hrefArray = await page.$$eval( 'table > tbody tr', trs =>
return trs.map( tr =>
return tr.querySelector( 'td:nth-child(1) a' ).href;
).filter( href => /^file.*idx$/.test( href ) );
);


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