/**

* @license

* Copyright Google LLC All Rights Reserved.

*

* Use of this source code is governed by an MIT-style license that can be

* found in the LICENSE file at https://angular.dev/license

*/

/**

* Returns element classes in form of a stable (sorted) string.

*

* @param element HTML Element.

* @returns Returns element classes in form of a stable (sorted) string.

*/

export function getSortedClassName(element: Element): string {

const names: string[] = Object.keys(getElementClasses(element));

names.sort();

return names.join(' ');

}

/**

* Returns element classes in form of a map.

*

* @param element HTML Element.

* @returns Map of class values.

*/

export function getElementClasses(element: Element): {[key: string]: true} {

const classes: {[key: string]: true} = {};

if (element.nodeType === Node.ELEMENT_NODE) {

const classList = element.classList;

for (let i = 0; i < classList.length; i++) {

const key = classList[i];

classes[key] = true;

}

}

return classes;

}

/**

* Returns element styles in form of a stable (sorted) string.

*

* @param element HTML Element.

* @returns Returns element styles in form of a stable (sorted) string.

*/

export function getSortedStyle(element: Element): string {

const styles = getElementStyles(element);

const names: string[] = Object.keys(styles);

names.sort();

let sorted = '';

names.forEach((key) => {

const value = styles[key];

if (value != null && value !== '') {

if (sorted !== '') sorted += ' ';

sorted += key + ': ' + value + ';';

}

});

return sorted;

}

/**

* Returns element styles in form of a map.

*

* @param element HTML Element.

* @returns Map of style values.

*/

export function getElementStyles(element: Element): {[key: string]: string} {

const styles: {[key: string]: string} = {};

if (element.nodeType === Node.ELEMENT_NODE) {

const style = (element as HTMLElement).style;

// reading `style.color` is a work around for a bug in Domino. The issue is that Domino has

// stale value for `style.length`. It seems that reading a property from the element causes the

// stale value to be updated. (As of Domino v 2.1.3)

style.color;

for (let i = 0; i < style.length; i++) {

const key = style.item(i);

const value = style.getPropertyValue(key);

if (value !== '') {

styles[key] = value;

}

}

}

return styles;

}