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February 5, 2017 13:01
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Endless scrolling table...
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| <!DOCTYPE html> | |
| <html lang="en"> | |
| <head> | |
| <meta charset="utf-8"> | |
| <title>lazy table</title> | |
| <link rel="stylesheet" href="style.css"> | |
| <script src="https://cdnjs.cloudflare.com/ajax/libs/underscore.js/1.8.3/underscore-min.js"></script> | |
| </head> | |
| <body> | |
| <table id="lazyTable"></table> | |
| </body> | |
| <script> | |
| const table = document.querySelector("#lazyTable") | |
| const range = n => [...Array(n).keys()] | |
| const randomInt = upper => Math.round(Math.random() * upper) + 1 | |
| const rowData = n => [`Row ${n}`, ...range(4).map(k => randomInt(10))] | |
| const rowDom = row => { | |
| const tr = document.createElement('tr') | |
| row.forEach((cell, index) => tr.insertCell(index).innerHTML = cell) | |
| return tr | |
| } | |
| const delay = (n) => () => { | |
| return [rowDom(rowData(n)), delay(n + 1)] | |
| } | |
| const take = function(fn, n) { | |
| return range(n).reduce(([fn, l], ele) => { | |
| const [s, t] = fn() | |
| return [t, [...l, s]] | |
| }, [fn, []]) | |
| } | |
| const trs = delay(1) | |
| const [firstRun, initial] = take(trs, 50) | |
| initial.forEach(row => table.appendChild(row)) | |
| let lastRun = firstRun, | |
| newRows = [] | |
| const scrollCallback = _.debounce(function() { | |
| if(window.scrollY + 50 > window.innerHeight) { | |
| [lastRun, newRows] = take(lastRun, 30) | |
| newRows.forEach(row => table.appendChild(row)) | |
| } | |
| }, 100) | |
| window.addEventListener("scroll", scrollCallback) | |
| </script> | |
| </html> |
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