source: trip-planner-front/node_modules/critters/src/css.js@ 6fe77af

Last change on this file since 6fe77af was e29cc2e, checked in by Ema <ema_spirova@…>, 3 years ago

primeNG components

  • Property mode set to 100644
File size: 5.8 KB
Line 
1/**
2 * Copyright 2018 Google LLC
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5 * use this file except in compliance with the License. You may obtain a copy of
6 * the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations under
14 * the License.
15 */
16
17import { parse, stringify } from 'postcss';
18
19/**
20 * Parse a textual CSS Stylesheet into a Stylesheet instance.
21 * Stylesheet is a mutable postcss AST with format similar to CSSOM.
22 * @see https://github.com/postcss/postcss/
23 * @private
24 * @param {String} stylesheet
25 * @returns {css.Stylesheet} ast
26 */
27export function parseStylesheet(stylesheet) {
28 return parse(stylesheet);
29}
30
31/**
32 * Serialize a postcss Stylesheet to a String of CSS.
33 * @private
34 * @param {css.Stylesheet} ast A Stylesheet to serialize, such as one returned from `parseStylesheet()`
35 * @param {Object} options Options used by the stringify logic
36 * @param {Boolean} [options.compress] Compress CSS output (removes comments, whitespace, etc)
37 */
38export function serializeStylesheet(ast, options) {
39 let cssStr = '';
40
41 stringify(ast, (result, node, type) => {
42 if (!options.compress) {
43 cssStr += result;
44 return;
45 }
46
47 // Simple minification logic
48 if (node?.type === 'comment') return;
49
50 if (node?.type === 'decl') {
51 const prefix = node.prop + node.raws.between;
52
53 cssStr += result.replace(prefix, prefix.trim());
54 return;
55 }
56
57 if (type === 'start') {
58 if (node.type === 'rule' && node.selectors) {
59 cssStr += node.selectors.join(',') + '{';
60 } else {
61 cssStr += result.replace(/\s\{$/, '{');
62 }
63 return;
64 }
65
66 if (type === 'end' && result === '}' && node?.raws?.semicolon) {
67 cssStr = cssStr.slice(0, -1);
68 }
69
70 cssStr += result.trim();
71 });
72
73 return cssStr;
74}
75
76/**
77 * Converts a walkStyleRules() iterator to mark nodes with `.$$remove=true` instead of actually removing them.
78 * This means they can be removed in a second pass, allowing the first pass to be nondestructive (eg: to preserve mirrored sheets).
79 * @private
80 * @param {Function} iterator Invoked on each node in the tree. Return `false` to remove that node.
81 * @returns {(rule) => void} nonDestructiveIterator
82 */
83export function markOnly(predicate) {
84 return (rule) => {
85 const sel = rule.selectors;
86 if (predicate(rule) === false) {
87 rule.$$remove = true;
88 }
89 rule.$$markedSelectors = rule.selectors;
90 if (rule._other) {
91 rule._other.$$markedSelectors = rule._other.selectors;
92 }
93 rule.selectors = sel;
94 };
95}
96
97/**
98 * Apply filtered selectors to a rule from a previous markOnly run.
99 * @private
100 * @param {css.Rule} rule The Rule to apply marked selectors to (if they exist).
101 */
102export function applyMarkedSelectors(rule) {
103 if (rule.$$markedSelectors) {
104 rule.selectors = rule.$$markedSelectors;
105 }
106 if (rule._other) {
107 applyMarkedSelectors(rule._other);
108 }
109}
110
111/**
112 * Recursively walk all rules in a stylesheet.
113 * @private
114 * @param {css.Rule} node A Stylesheet or Rule to descend into.
115 * @param {Function} iterator Invoked on each node in the tree. Return `false` to remove that node.
116 */
117export function walkStyleRules(node, iterator) {
118 node.nodes = node.nodes.filter((rule) => {
119 if (hasNestedRules(rule)) {
120 walkStyleRules(rule, iterator);
121 }
122 rule._other = undefined;
123 rule.filterSelectors = filterSelectors;
124 return iterator(rule) !== false;
125 });
126}
127
128/**
129 * Recursively walk all rules in two identical stylesheets, filtering nodes into one or the other based on a predicate.
130 * @private
131 * @param {css.Rule} node A Stylesheet or Rule to descend into.
132 * @param {css.Rule} node2 A second tree identical to `node`
133 * @param {Function} iterator Invoked on each node in the tree. Return `false` to remove that node from the first tree, true to remove it from the second.
134 */
135export function walkStyleRulesWithReverseMirror(node, node2, iterator) {
136 if (node2 === null) return walkStyleRules(node, iterator);
137
138 [node.nodes, node2.nodes] = splitFilter(
139 node.nodes,
140 node2.nodes,
141 (rule, index, rules, rules2) => {
142 const rule2 = rules2[index];
143 if (hasNestedRules(rule)) {
144 walkStyleRulesWithReverseMirror(rule, rule2, iterator);
145 }
146 rule._other = rule2;
147 rule.filterSelectors = filterSelectors;
148 return iterator(rule) !== false;
149 }
150 );
151}
152
153// Checks if a node has nested rules, like @media
154// @keyframes are an exception since they are evaluated as a whole
155function hasNestedRules(rule) {
156 return (
157 rule.nodes &&
158 rule.nodes.length &&
159 rule.nodes.some((n) => n.type === 'rule' || n.type === 'atrule') &&
160 rule.name !== 'keyframes'
161 );
162}
163
164// Like [].filter(), but applies the opposite filtering result to a second copy of the Array without a second pass.
165// This is just a quicker version of generating the compliment of the set returned from a filter operation.
166function splitFilter(a, b, predicate) {
167 const aOut = [];
168 const bOut = [];
169 for (let index = 0; index < a.length; index++) {
170 if (predicate(a[index], index, a, b)) {
171 aOut.push(a[index]);
172 } else {
173 bOut.push(a[index]);
174 }
175 }
176 return [aOut, bOut];
177}
178
179// can be invoked on a style rule to subset its selectors (with reverse mirroring)
180function filterSelectors(predicate) {
181 if (this._other) {
182 const [a, b] = splitFilter(
183 this.selectors,
184 this._other.selectors,
185 predicate
186 );
187 this.selectors = a;
188 this._other.selectors = b;
189 } else {
190 this.selectors = this.selectors.filter(predicate);
191 }
192}
Note: See TracBrowser for help on using the repository browser.