Left aligned and centered grid with flexbox

Question

I\'d like to implement a responsive grid-like layout using flexbox (without media queries). There can be variable number of elements in the grid. Each item should have fixed

Answer 1

CSS Grid

CSS Grid solution is the only elegant and flexible CSS solution.

.container {
  display: grid;
  grid-template-columns: repeat(auto-fill, 200px);
  grid-auto-rows: 200px;
  grid-gap: 10px;
  justify-content: center;
}

.item {
  background-color: purple;
  padding: 10px;
}

  
Flex item 1
  
Flex item 2
  
Flex item 3
  
Flex item 4
  
Flex item 5

Unfortunately, it doesn't have the best browser support, so if you need outdated browsers like IE you'll have to use Javascript to achieve this. It's due the fact that flexbox container occupies all width even in case when items don't.

Pure Javascript version

So basically we are calculating needed value of margin-left to center our flexbox items. This Javascript should work regardless of initial markup settings.

// get width of element with margins
function getOuterWidth(el) {
  var styles = window.getComputedStyle(el);
  var margins = parseFloat(styles["marginLeft"]) +
    parseFloat(styles["marginRight"]);

  return Math.ceil(el.getBoundingClientRect().width + margins);
}

// get width of element without paddings
function getContentWidth(el) {
  var styles = window.getComputedStyle(el);
  var paddings = parseFloat(styles["paddingLeft"]) +
    parseFloat(styles["paddingRight"]);

  return Math.ceil(el.getBoundingClientRect().width - paddings);
}

// Get top of element
function getTopOfElement(el) {
  return el.getBoundingClientRect().top;
}

var container = document.querySelector(".container");
var initialMarginLeft = parseFloat(window.getComputedStyle(container)["marginLeft"]);
// getting array of items
var items = Array.prototype.slice.call(document.querySelectorAll(".item"));

function centerItems() {
  if (items.length === 0) return 0;

  // set margin-left to initial value to recalculate it
  container.style.marginLeft = initialMarginLeft + "px";

  var topOfFirstItem = getTopOfElement(items[0]);
  var spaceTakenByElementsOnFirstLine = getOuterWidth(items[0]);

  for (var i = 1; i < items.length; i++) {
    // Break in case we are in second line
    if (getTopOfElement(items[i]) > topOfFirstItem)
      break;
    spaceTakenByElementsOnFirstLine += getOuterWidth(items[i]);
  }

  // Set margin-left to center elements
  var marginLeft = initialMarginLeft + (getContentWidth(container) - spaceTakenByElementsOnFirstLine) / 2;

  container.style.marginLeft = marginLeft + "px";
};

window.addEventListener("resize", centerItems);

centerItems();

.container {
  display: flex;
  flex-wrap: wrap;
}

.item {
  height: 200px;
  width: 200px;
  background-color: purple;
  padding: 10px;
  margin: 10px;
}

  
Flex item 1
  
Flex item 2
  
Flex item 3
  
Flex item 4
  
Flex item 5

jQuery version

// get width of element with margins
function getOuterWidth(el) {
  return $(el).outerWidth(true);
}

// get width of element without paddings
function getContentWidth(el) {
  return parseFloat($(el).css("width"));
}

function getTopOfElement(el) {
  return $(el).position().top;
}

var $container = $(".container");
var $items = $(".item");
var initialMarginLeft = parseFloat($container.css("margin-left"));

function centerItems() {
  if ($items.length === 0) return 0;

  // set margin-left to initial value to recalculate it
  $container.css("margin-left", initialMarginLeft + "px");

  var topOfFirstItem = getTopOfElement($items[0]);
  var spaceTakenByElementsOnFirstLine = getOuterWidth($items[0]);

  for (var i = 1; i < $items.length; i++) {
    // Break in case we are in second line
    if (getTopOfElement($items[i]) > topOfFirstItem)
      break;
    spaceTakenByElementsOnFirstLine += getOuterWidth($items[i]);
  }

  // Set margin left to center elements
  var marginLeft = initialMarginLeft + (getContentWidth($container) - spaceTakenByElementsOnFirstLine) / 2;

  $container.css("margin-left", marginLeft + "px");
};

$(window).resize(centerItems);

centerItems();

.container {
  display: flex;
  flex-wrap: wrap;
}

.item {
  height: 200px;
  width: 200px;
  background-color: purple;
  padding: 10px;
  margin: 10px;
}

  
Flex item 1
  
Flex item 2
  
Flex item 3
  
Flex item 4
  
Flex item 5