(function (global, factory) {
typeof exports === 'object' && typeof module !== 'undefined' ? module.exports = factory() :
typeof define === 'function' && define.amd ? define(factory) :
(global = global || self, global.dialogPolyfill = factory());
}(this, function () { 'use strict';
// nb. This is for IE10 and lower _only_.
var supportCustomEvent = window.CustomEvent;
if (!supportCustomEvent || typeof supportCustomEvent === 'object') {
supportCustomEvent = function CustomEvent(event, x) {
x = x || {};
var ev = document.createEvent('CustomEvent');
ev.initCustomEvent(event, !!x.bubbles, !!x.cancelable, x.detail || null);
return ev;
};
supportCustomEvent.prototype = window.Event.prototype;
}
/**
* @param {Element} el to check for stacking context
* @return {boolean} whether this el or its parents creates a stacking context
*/
function createsStackingContext(el) {
while (el && el !== document.body) {
var s = window.getComputedStyle(el);
var invalid = function(k, ok) {
return !(s[k] === undefined || s[k] === ok);
};
if (s.opacity < 1 ||
invalid('zIndex', 'auto') ||
invalid('transform', 'none') ||
invalid('mixBlendMode', 'normal') ||
invalid('filter', 'none') ||
invalid('perspective', 'none') ||
s['isolation'] === 'isolate' ||
s.position === 'fixed' ||
s.webkitOverflowScrolling === 'touch') {
return true;
}
el = el.parentElement;
}
return false;
}
/**
* Finds the nearest <dialog> from the passed element.
*
* @param {Element} el to search from
* @return {HTMLDialogElement} dialog found
*/
function findNearestDialog(el) {
while (el) {
if (el.localName === 'dialog') {
return /** @type {HTMLDialogElement} */ (el);
}
el = el.parentElement;
}
return null;
}
/**
* Blur the specified element, as long as it's not the HTML body element.
* This works around an IE9/10 bug - blurring the body causes Windows to
* blur the whole application.
*
* @param {Element} el to blur
*/
function safeBlur(el) {
if (el && el.blur && el !== document.body) {
el.blur();
}
}
/**
* @param {!NodeList} nodeList to search
* @param {Node} node to find
* @return {boolean} whether node is inside nodeList
*/
function inNodeList(nodeList, node) {
for (var i = 0; i < nodeList.length; ++i) {
if (nodeList[i] === node) {
return true;
}
}
return false;
}
/**
* @param {HTMLFormElement} el to check
* @return {boolean} whether this form has method="dialog"
*/
function isFormMethodDialog(el) {
if (!el || !el.hasAttribute('method')) {
return false;
}
return el.getAttribute('method').toLowerCase() === 'dialog';
}
/**
* @param {!HTMLDialogElement} dialog to upgrade
* @constructor
*/
function dialogPolyfillInfo(dialog) {
this.dialog_ = dialog;
this.replacedStyleTop_ = false;
this.openAsModal_ = false;
// Set a11y role. Browsers that support dialog implicitly know this already.
if (!dialog.hasAttribute('role')) {
dialog.setAttribute('role', 'dialog');
}
dialog.show = this.show.bind(this);
dialog.showModal = this.showModal.bind(this);
dialog.close = this.close.bind(this);
if (!('returnValue' in dialog)) {
dialog.returnValue = '';
}
if ('MutationObserver' in window) {
var mo = new MutationObserver(this.maybeHideModal.bind(this));
mo.observe(dialog, {attributes: true, attributeFilter: ['open']});
} else {
// IE10 and below support. Note that DOMNodeRemoved etc fire _before_ removal. They also
// seem to fire even if the element was removed as part of a parent removal. Use the removed
// events to force downgrade (useful if removed/immediately added).
var removed = false;
var cb = function() {
removed ? this.downgradeModal() : this.maybeHideModal();
removed = false;
}.bind(this);
var timeout;
var delayModel = function(ev) {
if (ev.target !== dialog) { return; } // not for a child element
var cand = 'DOMNodeRemoved';
removed |= (ev.type.substr(0, cand.length) === cand);
window.clearTimeout(timeout);
timeout = window.setTimeout(cb, 0);
};
['DOMAttrModified', 'DOMNodeRemoved', 'DOMNodeRemovedFromDocument'].forEach(function(name) {
dialog.addEventListener(name, delayModel);
});
}
// Note that the DOM is observed inside DialogManager while any dialog
// is being displayed as a modal, to catch modal removal from the DOM.
Object.defineProperty(dialog, 'open', {
set: this.setOpen.bind(this),
get: dialog.hasAttribute.bind(dialog, 'open')
});
this.backdrop_ = document.createElement('div');
this.backdrop_.className = 'backdrop';
this.backdrop_.addEventListener('click', this.backdropClick_.bind(this));
}
dialogPolyfillInfo.prototype = {
get dialog() {
return this.dialog_;
},
/**
* Maybe remove this dialog from the modal top layer. This is called when
* a modal dialog may no longer be tenable, e.g., when the dialog is no
* longer open or is no longer part of the DOM.
*/
maybeHideModal: function() {
if (this.dialog_.hasAttribute('open') && document.body.contains(this.dialog_)) { return; }
this.downgradeModal();
},
/**
* Remove this dialog from the modal top layer, leaving it as a non-modal.
*/
downgradeModal: function() {
if (!this.openAsModal_) { return; }
this.openAsModal_ = false;
this.dialog_.style.zIndex = '';
// This won't match the native <dialog> exactly because if the user set top on a centered
// polyfill dialog, that top gets thrown away when the dialog is closed. Not sure it's
// possible to polyfill this perfectly.
if (this.replacedStyleTop_) {
this.dialog_.style.top = '';
this.replacedStyleTop_ = false;
}
// Clear the backdrop and remove from the manager.
this.backdrop_.parentNode && this.backdrop_.parentNode.removeChild(this.backdrop_);
dialogPolyfill.dm.removeDialog(this);
},
/**
* @param {boolean} value whether to open or close this dialog
*/
setOpen: function(value) {
if (value) {
this.dialog_.hasAttribute('open') || this.dialog_.setAttribute('open', '');
} else {
this.dialog_.removeAttribute('open');
this.maybeHideModal(); // nb. redundant with MutationObserver
}
},
/**
* Handles clicks on the fake .backdrop element, redirecting them as if
* they were on the dialog itself.
*
* @param {!Event} e to redirect
*/
backdropClick_: function(e) {
if (!this.dialog_.hasAttribute('tabindex')) {
// Clicking on the backdrop should move the implicit cursor, even if dialog cannot be
// focused. Create a fake thing to focus on. If the backdrop was _before_ the dialog, this
// would not be needed - clicks would move the implicit cursor there.
var fake = document.createElement('div');
this.dialog_.insertBefore(fake, this.dialog_.firstChild);
fake.tabIndex = -1;
fake.focus();
this.dialog_.removeChild(fake);
} else {
this.dialog_.focus();
}
var redirectedEvent = document.createEvent('MouseEvents');
redirectedEvent.initMouseEvent(e.type, e.bubbles, e.cancelable, window,
e.detail, e.screenX, e.screenY, e.clientX, e.clientY, e.ctrlKey,
e.altKey, e.shiftKey, e.metaKey, e.button, e.relatedTarget);
this.dialog_.dispatchEvent(redirectedEvent);
e.stopPropagation();
},
/**
* Focuses on the first focusable element within the dialog. This will always blur the current
* focus, even if nothing within the dialog is found.
*/
focus_: function() {
// Find element with `autofocus` attribute, or fall back to the first form/tabindex control.
var target = this.dialog_.querySelector('[autofocus]:not([disabled])');
if (!target && this.dialog_.tabIndex >= 0) {
target = this.dialog_;
}
if (!target) {
// Note that this is 'any focusable area'. This list is probably not exhaustive, but the
// alternative involves stepping through and trying to focus everything.
var opts = ['button', 'input', 'keygen', 'select', 'textarea'];
var query = opts.map(function(el) {
return el + ':not([disabled])';
});
// TODO(samthor): tabindex values that are not numeric are not focusable.
query.push('[tabindex]:not([disabled]):not([tabindex=""])'); // tabindex != "", not disabled
target = this.dialog_.querySelector(query.join(', '));
}
safeBlur(document.activeElement);
target && target.focus();
},
/**
* Sets the zIndex for the backdrop and dialog.
*
* @param {number} dialogZ
* @param {number} backdropZ
*/
updateZIndex: function(dialogZ, backdropZ) {
if (dialogZ < backdropZ) {
throw new Error('dialogZ should never be < backdropZ');
}
this.dialog_.style.zIndex = dialogZ;
this.backdrop_.style.zIndex = backdropZ;
},
/**
* Shows the dialog. If the dialog is already open, this does nothing.
*/
show: function() {
if (!this.dialog_.open) {
this.setOpen(true);
this.focus_();
}
},
/**
* Show this dialog modally.
*/
showModal: function() {
if (this.dialog_.hasAttribute('open')) {
throw new Error('Failed to execute \'showModal\' on dialog: The element is already open, and therefore cannot be opened modally.');
}
if (!document.body.contains(this.dialog_)) {
throw new Error('Failed to execute \'showModal\' on dialog: The element is not in a Document.');
}
if (!dialogPolyfill.dm.pushDialog(this)) {
throw new Error('Failed to execute \'showModal\' on dialog: There are too many open modal dialogs.');
}
if (createsStackingContext(this.dialog_.parentElement)) {
console.warn('A dialog is being shown inside a stacking context. ' +
'This may cause it to be unusable. For more information, see this link: ' +
'https://github.com/GoogleChrome/dialog-polyfill/#stacking-context');
}
this.setOpen(true);
this.openAsModal_ = true;
// Optionally center vertically, relative to the current viewport.
if (dialogPolyfill.needsCentering(this.dialog_)) {
dialogPolyfill.reposition(this.dialog_);
this.replacedStyleTop_ = true;
} else {
this.replacedStyleTop_ = false;
}
// Insert backdrop.
this.dialog_.parentNode.insertBefore(this.backdrop_, this.dialog_.nextSibling);
// Focus on whatever inside the dialog.
this.focus_();
},
/**
* Closes this HTMLDialogElement. This is optional vs clearing the open
* attribute, however this fires a 'close' event.
*
* @param {string=} opt_returnValue to use as the returnValue
*/
close: function(opt_returnValue) {
if (!this.dialog_.hasAttribute('open')) {
throw new Error('Failed to execute \'close\' on dialog: The element does not have an \'open\' attribute, and therefore cannot be closed.');
}
this.setOpen(false);
// Leave returnValue untouched in case it was set directly on the element
if (opt_returnValue !== undefined) {
this.dialog_.returnValue = opt_returnValue;
}
// Triggering "close" event for any attached listeners on the <dialog>.
var closeEvent = new supportCustomEvent('close', {
bubbles: false,
cancelable: false
});
// If we have an onclose handler assigned and it's a function, call it
if(this.dialog_.onclose instanceof Function) {
this.dialog_.onclose(closeEvent);
}
// Dispatch the event as normal
this.dialog_.dispatchEvent(closeEvent);
}
};
var dialogPolyfill = {};
dialogPolyfill.reposition = function(element) {
var scrollTop = document.body.scrollTop || document.documentElement.scrollTop;
var topValue = scrollTop + (window.innerHeight - element.offsetHeight) / 2;
element.style.top = Math.max(scrollTop, topValue) + 'px';
};
dialogPolyfill.isInlinePositionSetByStylesheet = function(element) {
for (var i = 0; i < document.styleSheets.length; ++i) {
var styleSheet = document.styleSheets[i];
var cssRules = null;
// Some browsers throw on cssRules.
try {
cssRules = styleSheet.cssRules;
} catch (e) {}
if (!cssRules) { continue; }
for (var j = 0; j < cssRules.length; ++j) {
var rule = cssRules[j];
var selectedNodes = null;
// Ignore errors on invalid selector texts.
try {
selectedNodes = document.querySelectorAll(rule.selectorText);
} catch(e) {}
if (!selectedNodes || !inNodeList(selectedNodes, element)) {
continue;
}
var cssTop = rule.style.getPropertyValue('top');
var cssBottom = rule.style.getPropertyValue('bottom');
if ((cssTop && cssTop !== 'auto') || (cssBottom && cssBottom !== 'auto')) {
return true;
}
}
}
return false;
};
dialogPolyfill.needsCentering = function(dialog) {
var computedStyle = window.getComputedStyle(dialog);
if (computedStyle.position !== 'absolute') {
return false;
}
// We must determine whether the top/bottom specified value is non-auto. In
// WebKit/Blink, checking computedStyle.top == 'auto' is sufficient, but
// Firefox returns the used value. So we do this crazy thing instead: check
// the inline style and then go through CSS rules.
if ((dialog.style.top !== 'auto' && dialog.style.top !== '') ||
(dialog.style.bottom !== 'auto' && dialog.style.bottom !== '')) {
return false;
}
return !dialogPolyfill.isInlinePositionSetByStylesheet(dialog);
};
/**
* @param {!Element} element to force upgrade
*/
dialogPolyfill.forceRegisterDialog = function(element) {
if (window.HTMLDialogElement || element.showModal) {
console.warn('This browser already supports <dialog>, the polyfill ' +
'may not work correctly', element);
}
if (element.localName !== 'dialog') {
throw new Error('Failed to register dialog: The element is not a dialog.');
}
new dialogPolyfillInfo(/** @type {!HTMLDialogElement} */ (element));
};
/**
* @param {!Element} element to upgrade, if necessary
*/
dialogPolyfill.registerDialog = function(element) {
if (!element.showModal) {
dialogPolyfill.forceRegisterDialog(element);
}
};
/**
* @constructor
*/
dialogPolyfill.DialogManager = function() {
/** @type {!Array<!dialogPolyfillInfo>} */
this.pendingDialogStack = [];
var checkDOM = this.checkDOM_.bind(this);
// The overlay is used to simulate how a modal dialog blocks the document.
// The blocking dialog is positioned on top of the overlay, and the rest of
// the dialogs on the pending dialog stack are positioned below it. In the
// actual implementation, the modal dialog stacking is controlled by the
// top layer, where z-index has no effect.
this.overlay = document.createElement('div');
this.overlay.className = '_dialog_overlay';
this.overlay.addEventListener('click', function(e) {
this.forwardTab_ = undefined;
e.stopPropagation();
checkDOM([]); // sanity-check DOM
}.bind(this));
this.handleKey_ = this.handleKey_.bind(this);
this.handleFocus_ = this.handleFocus_.bind(this);
this.zIndexLow_ = 100000;
this.zIndexHigh_ = 100000 + 150;
this.forwardTab_ = undefined;
if ('MutationObserver' in window) {
this.mo_ = new MutationObserver(function(records) {
var removed = [];
records.forEach(function(rec) {
for (var i = 0, c; c = rec.removedNodes[i]; ++i) {
if (!(c instanceof Element)) {
continue;
} else if (c.localName === 'dialog') {
removed.push(c);
}
removed = removed.concat(c.querySelectorAll('dialog'));
}
});
removed.length && checkDOM(removed);
});
}
};
/**
* Called on the first modal dialog being shown. Adds the overlay and related
* handlers.
*/
dialogPolyfill.DialogManager.prototype.blockDocument = function() {
document.documentElement.addEventListener('focus', this.handleFocus_, true);
document.addEventListener('keydown', this.handleKey_);
this.mo_ && this.mo_.observe(document, {childList: true, subtree: true});
};
/**
* Called on the first modal dialog being removed, i.e., when no more modal
* dialogs are visible.
*/
dialogPolyfill.DialogManager.prototype.unblockDocument = function() {
document.documentElement.removeEventListener('focus', this.handleFocus_, true);
document.removeEventListener('keydown', this.handleKey_);
this.mo_ && this.mo_.disconnect();
};
/**
* Updates the stacking of all known dialogs.
*/
dialogPolyfill.DialogManager.prototype.updateStacking = function() {
var zIndex = this.zIndexHigh_;
for (var i = 0, dpi; dpi = this.pendingDialogStack[i]; ++i) {
dpi.updateZIndex(--zIndex, --zIndex);
if (i === 0) {
this.overlay.style.zIndex = --zIndex;
}
}
// Make the overlay a sibling of the dialog itself.
var last = this.pendingDialogStack[0];
if (last) {
var p = last.dialog.parentNode || document.body;
p.appendChild(this.overlay);
} else if (this.overlay.parentNode) {
this.overlay.parentNode.removeChild(this.overlay);
}
};
/**
* @param {Element} candidate to check if contained or is the top-most modal dialog
* @return {boolean} whether candidate is contained in top dialog
*/
dialogPolyfill.DialogManager.prototype.containedByTopDialog_ = function(candidate) {
while (candidate = findNearestDialog(candidate)) {
for (var i = 0, dpi; dpi = this.pendingDialogStack[i]; ++i) {
if (dpi.dialog === candidate) {
return i === 0; // only valid if top-most
}
}
candidate = candidate.parentElement;
}
return false;
};
dialogPolyfill.DialogManager.prototype.handleFocus_ = function(event) {
if (this.containedByTopDialog_(event.target)) { return; }
if (document.activeElement === document.documentElement) { return; }
event.preventDefault();
event.stopPropagation();
safeBlur(/** @type {Element} */ (event.target));
if (this.forwardTab_ === undefined) { return; } // move focus only from a tab key
var dpi = this.pendingDialogStack[0];
var dialog = dpi.dialog;
var position = dialog.compareDocumentPosition(event.target);
if (position & Node.DOCUMENT_POSITION_PRECEDING) {
if (this.forwardTab_) {
// forward
dpi.focus_();
} else if (event.target !== document.documentElement) {
// backwards if we're not already focused on <html>
document.documentElement.focus();
}
}
return false;
};
dialogPolyfill.DialogManager.prototype.handleKey_ = function(event) {
this.forwardTab_ = undefined;
if (event.keyCode === 27) {
event.preventDefault();
event.stopPropagation();
var cancelEvent = new supportCustomEvent('cancel', {
bubbles: false,
cancelable: true
});
var dpi = this.pendingDialogStack[0];
if (dpi && dpi.dialog.dispatchEvent(cancelEvent)) {
dpi.dialog.close();
}
} else if (event.keyCode === 9) {
this.forwardTab_ = !event.shiftKey;
}
};
/**
* Finds and downgrades any known modal dialogs that are no longer displayed. Dialogs that are
* removed and immediately readded don't stay modal, they become normal.
*
* @param {!Array<!HTMLDialogElement>} removed that have definitely been removed
*/
dialogPolyfill.DialogManager.prototype.checkDOM_ = function(removed) {
// This operates on a clone because it may cause it to change. Each change also calls
// updateStacking, which only actually needs to happen once. But who removes many modal dialogs
// at a time?!
var clone = this.pendingDialogStack.slice();
clone.forEach(function(dpi) {
if (removed.indexOf(dpi.dialog) !== -1) {
dpi.downgradeModal();
} else {
dpi.maybeHideModal();
}
});
};
/**
* @param {!dialogPolyfillInfo} dpi
* @return {boolean} whether the dialog was allowed
*/
dialogPolyfill.DialogManager.prototype.pushDialog = function(dpi) {
var allowed = (this.zIndexHigh_ - this.zIndexLow_) / 2 - 1;
if (this.pendingDialogStack.length >= allowed) {
return false;
}
if (this.pendingDialogStack.unshift(dpi) === 1) {
this.blockDocument();
}
this.updateStacking();
return true;
};
/**
* @param {!dialogPolyfillInfo} dpi
*/
dialogPolyfill.DialogManager.prototype.removeDialog = function(dpi) {
var index = this.pendingDialogStack.indexOf(dpi);
if (index === -1) { return; }
this.pendingDialogStack.splice(index, 1);
if (this.pendingDialogStack.length === 0) {
this.unblockDocument();
}
this.updateStacking();
};
dialogPolyfill.dm = new dialogPolyfill.DialogManager();
dialogPolyfill.formSubmitter = null;
dialogPolyfill.useValue = null;
/**
* Installs global handlers, such as click listers and native method overrides. These are needed
* even if a no dialog is registered, as they deal with <form method="dialog">.
*/
if (window.HTMLDialogElement === undefined) {
/**
* If HTMLFormElement translates method="DIALOG" into 'get', then replace the descriptor with
* one that returns the correct value.
*/
var testForm = document.createElement('form');
testForm.setAttribute('method', 'dialog');
if (testForm.method !== 'dialog') {
var methodDescriptor = Object.getOwnPropertyDescriptor(HTMLFormElement.prototype, 'method');
if (methodDescriptor) {
// nb. Some older iOS and older PhantomJS fail to return the descriptor. Don't do anything
// and don't bother to update the element.
var realGet = methodDescriptor.get;
methodDescriptor.get = function() {
if (isFormMethodDialog(this)) {
return 'dialog';
}
return realGet.call(this);
};
var realSet = methodDescriptor.set;
methodDescriptor.set = function(v) {
if (typeof v === 'string' && v.toLowerCase() === 'dialog') {
return this.setAttribute('method', v);
}
return realSet.call(this, v);
};
Object.defineProperty(HTMLFormElement.prototype, 'method', methodDescriptor);
}
}
/**
* Global 'click' handler, to capture the <input type="submit"> or <button> element which has
* submitted a <form method="dialog">. Needed as Safari and others don't report this inside
* document.activeElement.
*/
document.addEventListener('click', function(ev) {
dialogPolyfill.formSubmitter = null;
dialogPolyfill.useValue = null;
if (ev.defaultPrevented) { return; } // e.g. a submit which prevents default submission
var target = /** @type {Element} */ (ev.target);
if (!target || !isFormMethodDialog(target.form)) { return; }
var valid = (target.type === 'submit' && ['button', 'input'].indexOf(target.localName) > -1);
if (!valid) {
if (!(target.localName === 'input' && target.type === 'image')) { return; }
// this is a <input type="image">, which can submit forms
dialogPolyfill.useValue = ev.offsetX + ',' + ev.offsetY;
}
var dialog = findNearestDialog(target);
if (!dialog) { return; }
dialogPolyfill.formSubmitter = target;
}, false);
/**
* Replace the native HTMLFormElement.submit() method, as it won't fire the
* submit event and give us a chance to respond.
*/
var nativeFormSubmit = HTMLFormElement.prototype.submit;
var replacementFormSubmit = function () {
if (!isFormMethodDialog(this)) {
return nativeFormSubmit.call(this);
}
var dialog = findNearestDialog(this);
dialog && dialog.close();
};
HTMLFormElement.prototype.submit = replacementFormSubmit;
/**
* Global form 'dialog' method handler. Closes a dialog correctly on submit
* and possibly sets its return value.
*/
document.addEventListener('submit', function(ev) {
if (ev.defaultPrevented) { return; } // e.g. a submit which prevents default submission
var form = /** @type {HTMLFormElement} */ (ev.target);
if (!isFormMethodDialog(form)) { return; }
ev.preventDefault();
var dialog = findNearestDialog(form);
if (!dialog) { return; }
// Forms can only be submitted via .submit() or a click (?), but anyway: sanity-check that
// the submitter is correct before using its value as .returnValue.
var s = dialogPolyfill.formSubmitter;
if (s && s.form === form) {
dialog.close(dialogPolyfill.useValue || s.value);
} else {
dialog.close();
}
dialogPolyfill.formSubmitter = null;
}, false);
}
return dialogPolyfill;
}));