57 lines
1.9 KiB
JavaScript
57 lines
1.9 KiB
JavaScript
// https://github.com/substack/insert-css
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var containers = []; // will store container HTMLElement references
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var styleElements = []; // will store {prepend: HTMLElement, append: HTMLElement}
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var usage = 'insert-css: You need to provide a CSS string. Usage: insertCss(cssString[, options]).';
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function createStyleElement() {
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var styleElement = document.createElement('style');
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styleElement.setAttribute('type', 'text/css');
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return styleElement;
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} // eslint-disable-next-line @typescript-eslint/explicit-module-boundary-types
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function insertCss(css, options) {
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options = options || {};
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if (css === undefined) {
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throw new Error(usage);
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}
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var position = options.prepend === true ? 'prepend' : 'append';
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var container = options.container !== undefined ? options.container : document.querySelector('head');
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var containerId = containers.indexOf(container); // first time we see this container, create the necessary entries
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if (containerId === -1) {
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containerId = containers.push(container) - 1;
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styleElements[containerId] = {};
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} // try to get the correponding container + position styleElement, create it otherwise
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var styleElement;
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if (styleElements[containerId] !== undefined && styleElements[containerId][position] !== undefined) {
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styleElement = styleElements[containerId][position];
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} else {
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styleElement = styleElements[containerId][position] = createStyleElement();
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var referenceNode = position === 'prepend' ? container.childNodes[0] || null : null;
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container.insertBefore(styleElement, referenceNode);
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} // strip potential UTF-8 BOM if css was read from a file
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if (css.charCodeAt(0) === 0xfeff) {
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css = css.substr(1, css.length);
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} // actually add the stylesheet
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if (styleElement.styleSheet) {
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styleElement.styleSheet.cssText += css;
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} else {
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styleElement.textContent += css;
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}
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return styleElement;
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}
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export default insertCss; |