in js/bootstrap.bundle.js [2492:2536]
function update() {
// if popper is destroyed, don't perform any further update
if (this.state.isDestroyed) {
return;
}
var data = {
instance: this,
styles: {},
arrowStyles: {},
attributes: {},
flipped: false,
offsets: {}
};
// compute reference element offsets
data.offsets.reference = getReferenceOffsets(this.state, this.popper, this.reference, this.options.positionFixed);
// compute auto placement, store placement inside the data object,
// modifiers will be able to edit `placement` if needed
// and refer to originalPlacement to know the original value
data.placement = computeAutoPlacement(this.options.placement, data.offsets.reference, this.popper, this.reference, this.options.modifiers.flip.boundariesElement, this.options.modifiers.flip.padding);
// store the computed placement inside `originalPlacement`
data.originalPlacement = data.placement;
data.positionFixed = this.options.positionFixed;
// compute the popper offsets
data.offsets.popper = getPopperOffsets(this.popper, data.offsets.reference, data.placement);
data.offsets.popper.position = this.options.positionFixed ? 'fixed' : 'absolute';
// run the modifiers
data = runModifiers(this.modifiers, data);
// the first `update` will call `onCreate` callback
// the other ones will call `onUpdate` callback
if (!this.state.isCreated) {
this.state.isCreated = true;
this.options.onCreate(data);
} else {
this.options.onUpdate(data);
}
}