Import fiddle as a JS Module - chain fiddles together

by rhelminen

HTML

<script src="https://raw.githubusercontent.com/procurios/ResizeSensor/master/dist/resizeSensor.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="container-fluid" id="grdContainer">
  <div class="grid-container" id="grdSelector">
    <div>Item 1</div>
    <div>Item 1235645</div>
    <div>Item 42642645254251</div>
    <div>Item 164</div>
    <div>Item 16</div>
    <div>Item 13</div>
    <div>Item 133</div>
  </div>
</div>

JavaScript

var GRID_GAP = 3; // GRID-GAP of the grid
var iGridW = 0; // LAST comparative value of grid item width
var sizingWIP = false;
var GRID_LAYOUT = {
  'maxwidth': { /* CSS settings to compare item widths */
    display: "grid",
    gap: GRID_GAP + "px",
    "grid-template-columns": "none",
    "grid-auto-columns": "max-content"
  },
  'normal': { /* Normal CSS style to display the grid */
    display: "grid",
    gap: GRID_GAP + "px",
    "grid-template-columns": "repeat(auto-fit, minmax(" + iGridW + "px, 1fr)",
    "grid-auto-columns": "none"
  }
};

$(function() { // Shorthand for document.ready event
  evalGridItemMaxSize();
});

new ResizeSensor(document.getElementById("grdContainer"), function() {
  if(sizingWIP) return;
  sizingWIP = true;
  evalGridItemMaxSize();
  sizingWIP = false;
});


// EVALUATE GRID ITEM WIDTH TO MAX-CONTENT FOR *ALL* COLUMNS (equivalent to "grid-template-columns: repeat(auto-fit, max-content)" which *cannot* be set in CSS
//    (repeat(auto-fill... & repeat(auto-fit... *cannot* be used with intrinsic {min-content, max-content, auto})
function evalGridItemMaxSize() {
  $("#grdSelector").css(GRID_LAYOUT['maxwidth']);
  if ($("#someGridItemID").outerWidth() === iGridW) {
    $("#grdSelector").css(GRID_LAYOUT['normal']);
    return; //Exit if grid item max-width is same as last time
  }

  // Re-evaluate grid item width as a function of max-content of *all* items
  iGridW = $("#someGridItemID").outerWidth();
  GRID_LAYOUT['normal']['grid-template-columns'] = "repeat(auto-fit, minmax(" + iGridW + "px, 1fr)"
  $("#grdSelector").css(GRID_LAYOUT['normal']);
}