Joseph Izang
2 years ago
committed by
Aniket
parent
3d3d32d2d9
commit
3e48cd9697
@ -0,0 +1,286 @@ |
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import domToImage from 'dom-to-image'; |
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import { jsPDF } from 'jspdf'; |
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|
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const _cloneNode = (node, javascriptEnabled) => { |
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let child = node.firstChild |
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const clone = node.nodeType === 3 ? document.createTextNode(node.nodeValue) : node.cloneNode(false) |
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while (child) { |
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if (javascriptEnabled === true || child.nodeType !== 1 || child.nodeName !== 'SCRIPT') { |
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clone.appendChild(_cloneNode(child, javascriptEnabled)) |
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} |
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child = child.nextSibling |
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} |
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if (node.nodeType === 1) { |
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if (node.nodeName === 'CANVAS') { |
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clone.width = node.width |
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clone.height = node.height |
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clone.getContext('2d').drawImage(node, 0, 0) |
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} else if (node.nodeName === 'TEXTAREA' || node.nodeName === 'SELECT') { |
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clone.value = node.value |
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} |
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clone.addEventListener('load', (() => { |
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clone.scrollTop = node.scrollTop |
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clone.scrollLeft = node.scrollLeft |
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}), true) |
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} |
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return clone |
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} |
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|
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const _createElement = (tagName, {className, innerHTML, style}) => { |
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let i |
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let scripts |
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const el = document.createElement(tagName) |
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if (className) { |
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el.className = className |
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} |
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if (innerHTML) { |
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el.innerHTML = innerHTML |
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scripts = el.getElementsByTagName('script') |
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i = scripts.length |
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while (i-- > 0) { |
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scripts[i].parentNode.removeChild(scripts[i]) |
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} |
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} |
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for (const key in style) { |
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el.style[key] = style[key]; |
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} |
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return el; |
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}; |
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|
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const _isCanvasBlank = canvas => { |
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const blank = document.createElement('canvas'); |
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blank.width = canvas.width; |
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blank.height = canvas.height; |
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const ctx = blank.getContext('2d'); |
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ctx.fillStyle = '#FFFFFF'; |
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ctx.fillRect(0, 0, blank.width, blank.height); |
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return canvas.toDataURL() === blank.toDataURL(); |
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}; |
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|
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const downloadPdf = (dom, options, cb) => { |
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const a4Height = 841.89; |
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const a4Width = 595.28; |
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let overrideWidth; |
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let container; |
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let containerCSS; |
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let containerWidth; |
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let elements; |
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let excludeClassNames; |
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let excludeTagNames; |
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let filename; |
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let filterFn; |
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let innerRatio; |
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let overlay; |
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let overlayCSS; |
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let pageHeightPx; |
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let proxyUrl; |
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let compression = 'NONE'; |
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let scale; |
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let opts; |
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let offsetHeight; |
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let offsetWidth; |
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let scaleObj; |
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let style; |
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const transformOrigin = 'top left'; |
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const pdfOptions = { |
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orientation: 'l', |
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unit: 'pt', |
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format: 'a4' |
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}; |
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|
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({filename, excludeClassNames = [], excludeTagNames = ['button', 'input', 'select'], overrideWidth, proxyUrl, compression, scale} = options); |
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|
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overlayCSS = { |
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position: 'fixed', |
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zIndex: 1000, |
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opacity: 0, |
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left: 0, |
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right: 0, |
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bottom: 0, |
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top: 0, |
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backgroundColor: 'rgba(0,0,0,0.8)' |
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}; |
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if (overrideWidth) { |
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overlayCSS.width = `${overrideWidth}px`; |
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} |
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containerCSS = { |
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position: 'absolute', |
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left: 0, |
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right: 0, |
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top: 0, |
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height: 'auto', |
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margin: 'auto', |
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overflow: 'auto', |
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backgroundColor: 'white' |
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}; |
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overlay = _createElement('div', { |
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style: overlayCSS |
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}); |
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container = _createElement('div', { |
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style: containerCSS |
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}); |
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container.appendChild(_cloneNode(dom)); |
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overlay.appendChild(container); |
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document.body.appendChild(overlay); |
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innerRatio = a4Height / a4Width; |
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containerWidth = overrideWidth || container.getBoundingClientRect().width; |
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pageHeightPx = Math.floor(containerWidth * innerRatio); |
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elements = container.querySelectorAll('*'); |
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|
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for (let i = 0, len = excludeClassNames.length; i < len; i++) { |
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const clName = excludeClassNames[i]; |
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container.querySelectorAll(`.${clName}`).forEach(function(a) { |
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return a.remove(); |
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}); |
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} |
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|
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for (let j = 0, len1 = excludeTagNames.length; j < len1; j++) { |
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const tName = excludeTagNames[j]; |
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let els = container.getElementsByTagName(tName); |
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|
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for (let k = els.length - 1; k >= 0; k--) { |
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if (!els[k]) { |
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continue; |
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} |
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els[k].parentNode.removeChild(els[k]); |
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} |
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} |
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|
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Array.prototype.forEach.call(elements, el => { |
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let clientRect; |
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let endPage; |
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let nPages; |
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let pad; |
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let rules; |
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let startPage; |
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rules = { |
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before: false, |
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after: false, |
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avoid: true |
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}; |
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clientRect = el.getBoundingClientRect(); |
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if (rules.avoid && !rules.before) { |
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startPage = Math.floor(clientRect.top / pageHeightPx); |
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endPage = Math.floor(clientRect.bottom / pageHeightPx); |
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nPages = Math.abs(clientRect.bottom - clientRect.top) / pageHeightPx; |
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// Turn on rules.before if the el is broken and is at most one page long.
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if (endPage !== startPage && nPages <= 1) { |
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rules.before = true; |
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} |
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// Before: Create a padding div to push the element to the next page.
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if (rules.before) { |
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pad = _createElement('div', { |
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style: { |
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display: 'block', |
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height: `${pageHeightPx - clientRect.top % pageHeightPx}px` |
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} |
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}); |
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return el.parentNode.insertBefore(pad, el); |
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} |
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} |
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}); |
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|
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// Remove unnecessary elements from result pdf
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filterFn = ({classList, tagName}) => { |
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let cName; |
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let j; |
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let len; |
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let ref; |
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if (classList) { |
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for (j = 0, len = excludeClassNames.length; j < len; j++) { |
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cName = excludeClassNames[j]; |
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if (Array.prototype.indexOf.call(classList, cName) >= 0) { |
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return false; |
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} |
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} |
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} |
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ref = tagName != null ? tagName.toLowerCase() : undefined; |
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return excludeTagNames.indexOf(ref) < 0; |
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}; |
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opts = { |
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filter: filterFn, |
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proxy: proxyUrl |
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}; |
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if (scale) { |
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offsetWidth = container.offsetWidth; |
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offsetHeight = container.offsetHeight; |
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style = { |
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transform: 'scale(' + scale + ')', |
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transformOrigin: transformOrigin, |
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width: offsetWidth + 'px', |
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height: offsetHeight + 'px' |
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}; |
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scaleObj = { |
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width: offsetWidth * scale, |
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height: offsetHeight * scale, |
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quality: 1, |
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style: style |
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}; |
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opts = Object.assign(opts, scaleObj); |
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} |
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|
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return domToImage.toCanvas(container, opts).then(canvas => { |
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let h; |
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let imgData; |
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let nPages; |
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let page; |
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let pageCanvas; |
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let pageCtx; |
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let pageHeight; |
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let pdf; |
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let pxFullHeight; |
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let w; |
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// Remove overlay
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document.body.removeChild(overlay); |
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// Initialize the PDF.
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pdf = new jsPDF(pdfOptions); |
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// Calculate the number of pages.
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pxFullHeight = canvas.height; |
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nPages = Math.ceil(pxFullHeight / pageHeightPx); |
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// Define pageHeight separately so it can be trimmed on the final page.
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pageHeight = a4Height; |
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pageCanvas = document.createElement('canvas'); |
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pageCtx = pageCanvas.getContext('2d'); |
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pageCanvas.width = canvas.width; |
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pageCanvas.height = pageHeightPx; |
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page = 0; |
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while (page < nPages) { |
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if (page === nPages - 1 && pxFullHeight % pageHeightPx !== 0) { |
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pageCanvas.height = pxFullHeight % pageHeightPx; |
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pageHeight = pageCanvas.height * a4Width / pageCanvas.width; |
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} |
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w = pageCanvas.width; |
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h = pageCanvas.height; |
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pageCtx.fillStyle = 'white'; |
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pageCtx.fillRect(0, 0, w, h); |
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pageCtx.drawImage(canvas, 0, page * pageHeightPx, w, h, 0, 0, w, h); |
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// Don't create blank pages
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if (_isCanvasBlank(pageCanvas)) { |
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++page; |
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continue; |
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} |
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// Add the page to the PDF.
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if (page) { |
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pdf.addPage(); |
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} |
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imgData = pageCanvas.toDataURL('image/PNG'); |
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pdf.addImage(imgData, 'PNG', 0, 0, a4Width, pageHeight, undefined, compression); |
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++page; |
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} |
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if (typeof cb === "function") { |
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cb(pdf); |
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} |
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return pdf.save(filename); |
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}).catch(error => { |
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// Remove overlay
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document.body.removeChild(overlay); |
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if (typeof cb === "function") { |
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cb(null); |
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} |
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return console.error(error); |
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}); |
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}; |
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|
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module.exports = downloadPdf; |
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