html-to-image
Version:
Generates an image from a DOM node using HTML5 canvas and SVG.
188 lines • 7.74 kB
JavaScript
var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
function adopt(value) { return value instanceof P ? value : new P(function (resolve) { resolve(value); }); }
return new (P || (P = Promise))(function (resolve, reject) {
function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
function step(result) { result.done ? resolve(result.value) : adopt(result.value).then(fulfilled, rejected); }
step((generator = generator.apply(thisArg, _arguments || [])).next());
});
};
import { toArray } from './util';
import { shouldEmbed, embedResources } from './embedResources';
export function parseWebFontRules(clonedNode) {
return __awaiter(this, void 0, void 0, function* () {
return new Promise((resolve, reject) => {
if (!clonedNode.ownerDocument) {
reject(new Error('Provided element is not within a Document'));
}
resolve(toArray(clonedNode.ownerDocument.styleSheets));
})
.then(getCssRules)
.then(getWebFontRules);
});
}
export function embedWebFonts(clonedNode, options) {
return __awaiter(this, void 0, void 0, function* () {
return parseWebFontRules(clonedNode)
.then((rules) => Promise.all(rules.map((rule) => {
const baseUrl = rule.parentStyleSheet
? rule.parentStyleSheet.href
: null;
return embedResources(rule.cssText, baseUrl, options);
})))
.then((cssStrings) => cssStrings.join('\n'))
.then((cssString) => {
const styleNode = document.createElement('style');
const sytleContent = document.createTextNode(cssString);
styleNode.appendChild(sytleContent);
if (clonedNode.firstChild) {
clonedNode.insertBefore(styleNode, clonedNode.firstChild);
}
else {
clonedNode.appendChild(styleNode);
}
return clonedNode;
});
});
}
export function getCssRules(styleSheets) {
return __awaiter(this, void 0, void 0, function* () {
const ret = [];
const promises = [];
// First loop inlines imports
styleSheets.forEach((sheet) => {
if ('cssRules' in sheet) {
try {
toArray(sheet.cssRules).forEach((item) => {
if (item.type === CSSRule.IMPORT_RULE) {
promises.push(fetchCSS(item.href, sheet)
.then(embedFonts)
.then((cssText) => {
const parsed = parseCSS(cssText);
parsed.forEach((rule) => {
sheet.insertRule(rule, sheet.cssRules.length);
});
})
.catch((e) => {
console.log('Error loading remote css', e.toString());
}));
}
});
}
catch (e) {
const inline = styleSheets.find((a) => a.href === null) || document.styleSheets[0];
if (sheet.href != null) {
promises.push(fetchCSS(sheet.href, inline)
.then(embedFonts)
.then((cssText) => {
const parsed = parseCSS(cssText);
parsed.forEach((rule) => {
inline.insertRule(rule, sheet.cssRules.length);
});
})
.catch((e) => {
console.log('Error loading remote stylesheet', e.toString());
}));
}
console.log('Error inlining remote css file', e.toString());
}
}
});
return Promise.all(promises).then(() => {
// Second loop parses rules
styleSheets.forEach((sheet) => {
if ('cssRules' in sheet) {
try {
toArray(sheet.cssRules).forEach((item) => {
ret.push(item);
});
}
catch (e) {
console.log(`Error while reading CSS rules from ${sheet.href}`, e.toString());
}
}
});
return ret;
});
});
}
function getWebFontRules(cssRules) {
return cssRules
.filter((rule) => rule.type === CSSRule.FONT_FACE_RULE)
.filter((rule) => shouldEmbed(rule.style.getPropertyValue('src')));
}
function parseCSS(source) {
if (source === undefined) {
return [];
}
let cssText = source;
const css = [];
const cssKeyframeRegex = '((@.*?keyframes [\\s\\S]*?){([\\s\\S]*?}\\s*?)})';
const combinedCSSRegex = '((\\s*?(?:\\/\\*[\\s\\S]*?\\*\\/)?\\s*?@media[\\s\\S]' +
'*?){([\\s\\S]*?)}\\s*?})|(([\\s\\S]*?){([\\s\\S]*?)})'; // to match css & media queries together
const cssCommentsRegex = new RegExp('(\\/\\*[\\s\\S]*?\\*\\/)', 'gi');
// strip out comments
cssText = cssText.replace(cssCommentsRegex, '');
const keyframesRegex = new RegExp(cssKeyframeRegex, 'gi');
let arr;
while (true) {
arr = keyframesRegex.exec(cssText);
if (arr === null) {
break;
}
css.push(arr[0]);
}
cssText = cssText.replace(keyframesRegex, '');
// unified regex
const unified = new RegExp(combinedCSSRegex, 'gi');
while (true) {
arr = unified.exec(cssText);
if (arr === null) {
break;
}
css.push(arr[0]);
}
return css;
}
function fetchCSS(url, sheet) {
return fetch(url).then((res) => {
return {
url,
cssText: res.text(),
};
}, (e) => {
console.log('ERROR FETCHING CSS: ', e.toString());
});
}
function embedFonts(data) {
return __awaiter(this, void 0, void 0, function* () {
return data.cssText.then((resolved) => {
let cssText = resolved;
const regexUrlFind = /url\(["']?([^"')]+)["']?\)/g;
const fontLocations = cssText.match(/url\([^)]+\)/g) || [];
const fontLoadedPromises = fontLocations.map((location) => {
let url = location.replace(regexUrlFind, '$1');
if (!url.startsWith('https://')) {
const source = data.url;
url = new URL(url, source).href;
}
return new Promise((resolve, reject) => {
fetch(url)
.then((res) => res.blob())
.then((blob) => {
const reader = new FileReader();
reader.addEventListener('load', (res) => {
// Side Effect
cssText = cssText.replace(location, `url(${reader.result})`);
resolve([location, reader.result]);
});
reader.readAsDataURL(blob);
})
.catch(reject);
});
});
return Promise.all(fontLoadedPromises).then(() => cssText);
});
});
}
//# sourceMappingURL=embedWebFonts.js.map