117 lines
3.7 KiB
TypeScript
117 lines
3.7 KiB
TypeScript
/**
|
|
* @license
|
|
* Copyright Google Inc. 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.io/license
|
|
*/
|
|
|
|
const enum Char {
|
|
OpenParen = 40,
|
|
CloseParen = 41,
|
|
Colon = 58,
|
|
Semicolon = 59,
|
|
BackSlash = 92,
|
|
QuoteNone = 0, // indicating we are not inside a quote
|
|
QuoteDouble = 34,
|
|
QuoteSingle = 39,
|
|
}
|
|
|
|
|
|
/**
|
|
* Parses string representation of a style and converts it into object literal.
|
|
*
|
|
* @param value string representation of style as used in the `style` attribute in HTML.
|
|
* Example: `color: red; height: auto`.
|
|
* @returns An array of style property name and value pairs, e.g. `['color', 'red', 'height',
|
|
* 'auto']`
|
|
*/
|
|
export function parse(value: string): string[] {
|
|
// we use a string array here instead of a string map
|
|
// because a string-map is not guaranteed to retain the
|
|
// order of the entries whereas a string array can be
|
|
// construted in a [key, value, key, value] format.
|
|
const styles: string[] = [];
|
|
|
|
let i = 0;
|
|
let parenDepth = 0;
|
|
let quote: Char = Char.QuoteNone;
|
|
let valueStart = 0;
|
|
let propStart = 0;
|
|
let currentProp: string|null = null;
|
|
let valueHasQuotes = false;
|
|
while (i < value.length) {
|
|
const token = value.charCodeAt(i++) as Char;
|
|
switch (token) {
|
|
case Char.OpenParen:
|
|
parenDepth++;
|
|
break;
|
|
case Char.CloseParen:
|
|
parenDepth--;
|
|
break;
|
|
case Char.QuoteSingle:
|
|
// valueStart needs to be there since prop values don't
|
|
// have quotes in CSS
|
|
valueHasQuotes = valueHasQuotes || valueStart > 0;
|
|
if (quote === Char.QuoteNone) {
|
|
quote = Char.QuoteSingle;
|
|
} else if (quote === Char.QuoteSingle && value.charCodeAt(i - 1) !== Char.BackSlash) {
|
|
quote = Char.QuoteNone;
|
|
}
|
|
break;
|
|
case Char.QuoteDouble:
|
|
// same logic as above
|
|
valueHasQuotes = valueHasQuotes || valueStart > 0;
|
|
if (quote === Char.QuoteNone) {
|
|
quote = Char.QuoteDouble;
|
|
} else if (quote === Char.QuoteDouble && value.charCodeAt(i - 1) !== Char.BackSlash) {
|
|
quote = Char.QuoteNone;
|
|
}
|
|
break;
|
|
case Char.Colon:
|
|
if (!currentProp && parenDepth === 0 && quote === Char.QuoteNone) {
|
|
currentProp = hyphenate(value.substring(propStart, i - 1).trim());
|
|
valueStart = i;
|
|
}
|
|
break;
|
|
case Char.Semicolon:
|
|
if (currentProp && valueStart > 0 && parenDepth === 0 && quote === Char.QuoteNone) {
|
|
const styleVal = value.substring(valueStart, i - 1).trim();
|
|
styles.push(currentProp, valueHasQuotes ? stripUnnecessaryQuotes(styleVal) : styleVal);
|
|
propStart = i;
|
|
valueStart = 0;
|
|
currentProp = null;
|
|
valueHasQuotes = false;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (currentProp && valueStart) {
|
|
const styleVal = value.substr(valueStart).trim();
|
|
styles.push(currentProp, valueHasQuotes ? stripUnnecessaryQuotes(styleVal) : styleVal);
|
|
}
|
|
|
|
return styles;
|
|
}
|
|
|
|
export function stripUnnecessaryQuotes(value: string): string {
|
|
const qS = value.charCodeAt(0);
|
|
const qE = value.charCodeAt(value.length - 1);
|
|
if (qS == qE && (qS == Char.QuoteSingle || qS == Char.QuoteDouble)) {
|
|
const tempValue = value.substring(1, value.length - 1);
|
|
// special case to avoid using a multi-quoted string that was just chomped
|
|
// (e.g. `font-family: "Verdana", "sans-serif"`)
|
|
if (tempValue.indexOf('\'') == -1 && tempValue.indexOf('"') == -1) {
|
|
value = tempValue;
|
|
}
|
|
}
|
|
return value;
|
|
}
|
|
|
|
export function hyphenate(value: string): string {
|
|
return value.replace(/[a-z][A-Z]/g, v => {
|
|
return v.charAt(0) + '-' + v.charAt(1);
|
|
}).toLowerCase();
|
|
}
|