未验证 提交 989af238 编写于 作者: D daminglu 提交者: GitHub

Added a JS lib to help download graph image (#387)

上级 42561cea
......@@ -14,8 +14,6 @@
"dependencies": {
"axios": "^0.16.1",
"csshint": "^0.3.3",
"cytoscape": "^3.2.11",
"cytoscape-dagre": "^2.2.0",
"d3": "^4.7.4",
"d3-format": "^1.2.1",
"dagre": "^0.8.2",
......
......@@ -11,6 +11,10 @@
// service
import {getPluginGraphsGraph} from '../../service';
// The name 'svgToPngDownloadHelper' is just a placeholder.
// Loading the JS lib file will bind saveSvgAsPng to window.
import * as svgToPngDownloadHelper from './svgToPngDownloadHelper.js';
// for d3 drawing
import * as d3 from 'd3';
......@@ -31,32 +35,8 @@ export default {
watch: {
doDownload: function(val) {
if (this.doDownload) {
// TODO(daming-lu): .svg is ugly and colorless.
let svg = this.$refs.graphSvg;
// get svg source.
let serializer = new XMLSerializer();
let source = serializer.serializeToString(svg);
// add name spaces.
if (!source.match(/^<svg[^>]+xmlns="http\:\/\/www\.w3\.org\/2000\/svg"/)) {
source = source.replace(/^<svg/, '<svg xmlns="http://www.w3.org/2000/svg"');
}
if (!source.match(/^<svg[^>]+"http\:\/\/www\.w3\.org\/1999\/xlink"/)) {
source = source.replace(/^<svg/, '<svg xmlns:xlink="http://www.w3.org/1999/xlink"');
}
// add xml declaration
source = '<?xml version="1.0" standalone="no"?>\r\n' + source;
// convert svg source to URI data scheme.
let url = 'data:image/svg+xml;charset=utf-8,'+encodeURIComponent(source);
let a = document.createElement('a');
a.download = 'graph.svg';
a.href = url;
a.click();
saveSvgAsPng(svg, "graph.png", {scale: 1.0});
this.$emit('triggerDownload', false);
}
},
......
// URL for this library : https://github.com/exupero/saveSvgAsPng
// Blog about it: https://spin.atomicobject.com/2014/01/21/convert-svg-to-png/
(function() {
var out$ = window;
var doctype = '<?xml version="1.0" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd" [<!ENTITY nbsp "&#160;">]>';
function isElement(obj) {
return obj instanceof HTMLElement || obj instanceof SVGElement;
}
function requireDomNode(el) {
if (!isElement(el)) {
throw new Error('an HTMLElement or SVGElement is required; got ' + el);
}
}
function isExternal(url) {
return url && url.lastIndexOf('http',0) == 0 && url.lastIndexOf(window.location.host) == -1;
}
function inlineImages(el, callback) {
requireDomNode(el);
var images = el.querySelectorAll('image'),
left = images.length,
checkDone = function() {
if (left === 0) {
callback();
}
};
checkDone();
for (var i = 0; i < images.length; i++) {
(function(image) {
var href = image.getAttributeNS("http://www.w3.org/1999/xlink", "href");
var canvas = document.createElement('canvas');
var ctx = canvas.getContext('2d');
var img = new Image();
img.crossOrigin="anonymous";
href = href || image.getAttribute('href');
if (isExternal(href)) {
href += (href.indexOf('?') === -1 ? '?' : '&') + 't=' + (new Date().valueOf());
}
if (href) {
img.src = href;
img.onload = function() {
canvas.width = img.width;
canvas.height = img.height;
ctx.drawImage(img, 0, 0);
image.setAttributeNS("http://www.w3.org/1999/xlink", "href", canvas.toDataURL('image/png'));
left--;
checkDone();
}
img.onerror = function() {
console.log("Could not load "+href);
left--;
checkDone();
}
} else {
left--;
checkDone();
}
})(images[i]);
}
}
function styles(el, options, cssLoadedCallback) {
var selectorRemap = options.selectorRemap;
var modifyStyle = options.modifyStyle;
var modifyCss = options.modifyCss || function(selector, properties) {
var selector = selectorRemap ? selectorRemap(selector) : selector;
var cssText = modifyStyle ? modifyStyle(properties) : properties;
return selector + " { " + cssText + " }\n";
};
var css = "";
// Each font that has an external link is saved into queue, and processed asynchronously.
var fontsQueue = [];
var sheets = document.styleSheets;
for (var i = 0; i < sheets.length; i++) {
try {
var rules = sheets[i].cssRules;
} catch (e) {
console.warn("Stylesheet could not be loaded: "+sheets[i].href);
continue;
}
if (rules != null) {
for (var j = 0, match; j < rules.length; j++, match = null) {
var rule = rules[j];
if (typeof(rule.style) != "undefined") {
var selectorText;
try {
selectorText = rule.selectorText;
} catch(err) {
console.warn('The following CSS rule has an invalid selector: "' + rule + '"', err);
}
try {
if (selectorText) {
match = el.querySelector(selectorText) || (el.parentNode && el.parentNode.querySelector(selectorText));
}
} catch(err) {
console.warn('Invalid CSS selector "' + selectorText + '"', err);
}
if (match) {
css += modifyCss(rule.selectorText, rule.style.cssText);
} else if(rule.cssText.match(/^@font-face/)) {
// below we are trying to find matches to external link. E.g.
// @font-face {
// // ...
// src: local('Abel'), url(https://fonts.gstatic.com/s/abel/v6/UzN-iejR1VoXU2Oc-7LsbvesZW2xOQ-xsNqO47m55DA.woff2);
// }
//
// This regex will save extrnal link into first capture group
var fontUrlRegexp = /url\(["']?(.+?)["']?\)/;
// TODO: This needs to be changed to support multiple url declarations per font.
var fontUrlMatch = rule.cssText.match(fontUrlRegexp);
var externalFontUrl = (fontUrlMatch && fontUrlMatch[1]) || '';
var fontUrlIsDataURI = externalFontUrl.match(/^data:/);
if (fontUrlIsDataURI) {
// We should ignore data uri - they are already embedded
externalFontUrl = '';
}
if (externalFontUrl === 'about:blank') {
// no point trying to load this
externalFontUrl = '';
}
if (externalFontUrl) {
// okay, we are lucky. We can fetch this font later
//handle url if relative
if (externalFontUrl.startsWith('../')) {
externalFontUrl = sheets[i].href + '/../' + externalFontUrl
} else if (externalFontUrl.startsWith('./')) {
externalFontUrl = sheets[i].href + '/.' + externalFontUrl
}
fontsQueue.push({
text: rule.cssText,
// Pass url regex, so that once font is downladed, we can run `replace()` on it
fontUrlRegexp: fontUrlRegexp,
format: getFontMimeTypeFromUrl(externalFontUrl),
url: externalFontUrl
});
} else {
// otherwise, use previous logic
css += rule.cssText + '\n';
}
}
}
}
}
}
// Now all css is processed, it's time to handle scheduled fonts
processFontQueue(fontsQueue);
function getFontMimeTypeFromUrl(fontUrl) {
var supportedFormats = {
'woff2': 'font/woff2',
'woff': 'font/woff',
'otf': 'application/x-font-opentype',
'ttf': 'application/x-font-ttf',
'eot': 'application/vnd.ms-fontobject',
'sfnt': 'application/font-sfnt',
'svg': 'image/svg+xml'
};
var extensions = Object.keys(supportedFormats);
for (var i = 0; i < extensions.length; ++i) {
var extension = extensions[i];
// TODO: This is not bullet proof, it needs to handle edge cases...
if (fontUrl.indexOf('.' + extension) > 0) {
return supportedFormats[extension];
}
}
// If you see this error message, you probably need to update code above.
console.error('Unknown font format for ' + fontUrl+ '; Fonts may not be working correctly');
return 'application/octet-stream';
}
function processFontQueue(queue) {
if (queue.length > 0) {
// load fonts one by one until we have anything in the queue:
var font = queue.pop();
processNext(font);
} else {
// no more fonts to load.
cssLoadedCallback(css);
}
function processNext(font) {
// TODO: This could benefit from caching.
var oReq = new XMLHttpRequest();
oReq.addEventListener('load', fontLoaded);
oReq.addEventListener('error', transferFailed);
oReq.addEventListener('abort', transferFailed);
oReq.open('GET', font.url);
oReq.responseType = 'arraybuffer';
oReq.send();
function fontLoaded() {
// TODO: it may be also worth to wait until fonts are fully loaded before
// attempting to rasterize them. (e.g. use https://developer.mozilla.org/en-US/docs/Web/API/FontFaceSet )
var fontBits = oReq.response;
var fontInBase64 = arrayBufferToBase64(fontBits);
updateFontStyle(font, fontInBase64);
}
function transferFailed(e) {
console.warn('Failed to load font from: ' + font.url);
console.warn(e)
css += font.text + '\n';
processFontQueue(queue);
}
function updateFontStyle(font, fontInBase64) {
var dataUrl = 'url("data:' + font.format + ';base64,' + fontInBase64 + '")';
css += font.text.replace(font.fontUrlRegexp, dataUrl) + '\n';
// schedule next font download on next tick.
setTimeout(function() {
processFontQueue(queue)
}, 0);
}
}
}
function arrayBufferToBase64(buffer) {
var binary = '';
var bytes = new Uint8Array(buffer);
var len = bytes.byteLength;
for (var i = 0; i < len; i++) {
binary += String.fromCharCode(bytes[i]);
}
return window.btoa(binary);
}
}
function getDimension(el, clone, dim) {
var v = (el.viewBox && el.viewBox.baseVal && el.viewBox.baseVal[dim]) ||
(clone.getAttribute(dim) !== null && !clone.getAttribute(dim).match(/%$/) && parseInt(clone.getAttribute(dim))) ||
el.getBoundingClientRect()[dim] ||
parseInt(clone.style[dim]) ||
parseInt(window.getComputedStyle(el).getPropertyValue(dim));
return (typeof v === 'undefined' || v === null || isNaN(parseFloat(v))) ? 0 : v;
}
function reEncode(data) {
data = encodeURIComponent(data);
data = data.replace(/%([0-9A-F]{2})/g, function(match, p1) {
var c = String.fromCharCode('0x'+p1);
return c === '%' ? '%25' : c;
});
return decodeURIComponent(data);
}
out$.prepareSvg = function(el, options, cb) {
requireDomNode(el);
options = options || {};
options.scale = options.scale || 1;
options.responsive = options.responsive || false;
var xmlns = "http://www.w3.org/2000/xmlns/";
inlineImages(el, function() {
var outer = document.createElement("div");
var clone = el.cloneNode(true);
var width, height;
if(el.tagName == 'svg') {
width = options.width || getDimension(el, clone, 'width');
height = options.height || getDimension(el, clone, 'height');
} else if(el.getBBox) {
var box = el.getBBox();
width = box.x + box.width;
height = box.y + box.height;
clone.setAttribute('transform', clone.getAttribute('transform').replace(/translate\(.*?\)/, ''));
var svg = document.createElementNS('http://www.w3.org/2000/svg','svg')
svg.appendChild(clone)
clone = svg;
} else {
console.error('Attempted to render non-SVG element', el);
return;
}
clone.setAttribute("version", "1.1");
if (!clone.getAttribute('xmlns')) {
clone.setAttributeNS(xmlns, "xmlns", "http://www.w3.org/2000/svg");
}
if (!clone.getAttribute('xmlns:xlink')) {
clone.setAttributeNS(xmlns, "xmlns:xlink", "http://www.w3.org/1999/xlink");
}
if (options.responsive) {
clone.removeAttribute('width');
clone.removeAttribute('height');
clone.setAttribute('preserveAspectRatio', 'xMinYMin meet');
} else {
clone.setAttribute("width", width * options.scale);
clone.setAttribute("height", height * options.scale);
}
clone.setAttribute("viewBox", [
options.left || 0,
options.top || 0,
width,
height
].join(" "));
var fos = clone.querySelectorAll('foreignObject > *');
for (var i = 0; i < fos.length; i++) {
if (!fos[i].getAttribute('xmlns')) {
fos[i].setAttributeNS(xmlns, "xmlns", "http://www.w3.org/1999/xhtml");
}
}
outer.appendChild(clone);
// In case of custom fonts we need to fetch font first, and then inline
// its url into data-uri format (encode as base64). That's why style
// processing is done asynchonously. Once all inlining is finshed
// cssLoadedCallback() is called.
styles(el, options, cssLoadedCallback);
function cssLoadedCallback(css) {
// here all fonts are inlined, so that we can render them properly.
var s = document.createElement('style');
s.setAttribute('type', 'text/css');
s.innerHTML = "<![CDATA[\n" + css + "\n]]>";
var defs = document.createElement('defs');
defs.appendChild(s);
clone.insertBefore(defs, clone.firstChild);
if (cb) {
var outHtml = outer.innerHTML;
outHtml = outHtml.replace(/NS\d+:href/gi, 'xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href');
cb(outHtml, width, height);
}
}
});
}
out$.svgAsDataUri = function(el, options, cb) {
out$.prepareSvg(el, options, function(svg) {
var uri = 'data:image/svg+xml;base64,' + window.btoa(reEncode(doctype + svg));
if (cb) {
cb(uri);
}
});
}
out$.svgAsPngUri = function(el, options, cb) {
requireDomNode(el);
options = options || {};
options.encoderType = options.encoderType || 'image/png';
options.encoderOptions = options.encoderOptions || 0.8;
var convertToPng = function(src, w, h) {
var canvas = document.createElement('canvas');
var context = canvas.getContext('2d');
canvas.width = w;
canvas.height = h;
var pixelRatio = window.devicePixelRatio || 1;
canvas.style.width = canvas.width+'px';
canvas.style.height = canvas.height+'px';
canvas.width *= pixelRatio;
canvas.height *= pixelRatio;
context.setTransform(pixelRatio,0,0,pixelRatio,0,0);
if(options.canvg) {
options.canvg(canvas, src);
} else {
context.drawImage(src, 0, 0);
}
if(options.backgroundColor){
context.globalCompositeOperation = 'destination-over';
context.fillStyle = options.backgroundColor;
context.fillRect(0, 0, canvas.width, canvas.height);
}
var png;
try {
png = canvas.toDataURL(options.encoderType, options.encoderOptions);
} catch (e) {
if ((typeof SecurityError !== 'undefined' && e instanceof SecurityError) || e.name == "SecurityError") {
console.error("Rendered SVG images cannot be downloaded in this browser.");
return;
} else {
throw e;
}
}
cb(png);
}
if(options.canvg) {
out$.prepareSvg(el, options, convertToPng);
} else {
out$.svgAsDataUri(el, options, function(uri) {
var image = new Image();
image.onload = function() {
convertToPng(image, image.width, image.height);
}
image.onerror = function() {
console.error(
'There was an error loading the data URI as an image on the following SVG\n',
window.atob(uri.slice(26)), '\n',
"Open the following link to see browser's diagnosis\n",
uri);
}
image.src = uri;
});
}
}
out$.download = function(name, uri) {
if (navigator.msSaveOrOpenBlob) {
navigator.msSaveOrOpenBlob(uriToBlob(uri), name);
} else {
var saveLink = document.createElement('a');
var downloadSupported = 'download' in saveLink;
if (downloadSupported) {
saveLink.download = name;
saveLink.style.display = 'none';
document.body.appendChild(saveLink);
try {
var blob = uriToBlob(uri);
var url = URL.createObjectURL(blob);
saveLink.href = url;
saveLink.onclick = function() {
requestAnimationFrame(function() {
URL.revokeObjectURL(url);
})
};
} catch (e) {
console.warn('This browser does not support object URLs. Falling back to string URL.');
saveLink.href = uri;
}
saveLink.click();
document.body.removeChild(saveLink);
}
else {
window.open(uri, '_temp', 'menubar=no,toolbar=no,status=no');
}
}
}
function uriToBlob(uri) {
var byteString = window.atob(uri.split(',')[1]);
var mimeString = uri.split(',')[0].split(':')[1].split(';')[0]
var buffer = new ArrayBuffer(byteString.length);
var intArray = new Uint8Array(buffer);
for (var i = 0; i < byteString.length; i++) {
intArray[i] = byteString.charCodeAt(i);
}
return new Blob([buffer], {type: mimeString});
}
out$.saveSvg = function(el, name, options) {
requireDomNode(el);
options = options || {};
out$.svgAsDataUri(el, options, function(uri) {
out$.download(name, uri);
});
}
out$.saveSvgAsPng = function(el, name, options) {
requireDomNode(el);
options = options || {};
out$.svgAsPngUri(el, options, function(uri) {
out$.download(name, uri);
});
}
// if define is defined create as an AMD module
if (typeof define !== 'undefined') {
define(function() {
return out$;
});
}
})();
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