saveSvgAsPng.js

(function() {
  var out$ = typeof exports != 'undefined' && exports || typeof define != 'undefined' && {} || this;

  var doctype = '<?xml version="1.0" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "https://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">';

  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("https://www.w3.org/1999/xlink", "href");
        if (href) {
          if (isExternal(href.value)) {
            console.warn("Cannot render embedded images linking to external hosts: "+href.value);
            return;
          }
        }
        var canvas = document.createElement('canvas');
        var ctx = canvas.getContext('2d');
        var img = new Image();
        href = href || image.getAttribute('href');
        if (href) {
          img.src = href;
          img.onload = function() {
            canvas.width = img.width;
            canvas.height = img.height;
            ctx.drawImage(img, 0, 0);
            image.setAttributeNS("https://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, selectorRemap) {
    var css = "";
    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; j < rules.length; j++) {
          var rule = rules[j];
          if (typeof(rule.style) != "undefined") {
            var match, 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);
              }
            } catch(err) {
              console.warn('Invalid CSS selector "' + selectorText + '"', err);
            }

            if (match) {
              var selector = selectorRemap ? selectorRemap(rule.selectorText) : rule.selectorText;
              css += selector + " { " + rule.style.cssText + " }\n";
            } else if(rule.cssText.match(/^@font-face/)) {
              css += rule.cssText + '\n';
            }
          }
        }
      }
    }
    return css;
  }

  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$.svgAsDataUri = function(el, options, cb) {
    requireDomNode(el);

    options = options || {};
    options.scale = options.scale || 1;
    var xmlns = "https://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('https://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", "https://www.w3.org/2000/svg");
      }
      if (!clone.getAttribute('xmlns:xlink')) {
        clone.setAttributeNS(xmlns, "xmlns:xlink", "https://www.w3.org/1999/xlink");
      }
      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++) {
        fos[i].setAttributeNS(xmlns, "xmlns", "https://www.w3.org/1999/xhtml");
      }

      outer.appendChild(clone);

      var css = styles(el, options.selectorRemap);
      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);

      var svg = doctype + outer.innerHTML;
      var uri = 'data:image/svg+xml;base64,' + window.btoa(reEncode(svg));
      if (cb) {
        cb(uri);
      }
    });
  }

  out$.svgAsPngUri = function(el, options, cb) {
    requireDomNode(el);

    out$.svgAsDataUri(el, options, function(uri) {
      var image = new Image();
      image.onload = function() {
        var canvas = document.createElement('canvas');
        canvas.width = image.width;
        canvas.height = image.height;
        var context = canvas.getContext('2d');
        if(options && options.backgroundColor){
          context.fillStyle = options.backgroundColor;
          context.fillRect(0, 0, canvas.width, canvas.height);
        }
        context.drawImage(image, 0, 0);
        var a = document.createElement('a'), png;
        try {
          png = canvas.toDataURL('image/png');
        } 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);
      }
      image.onerror = function(error) {
        console.error('There was an error loading the data URI as an image', error);
      }
      image.src = uri;
    });
  }

  function download(name, uri) {
    var a = document.createElement('a');
    a.download = name;
    a.href = uri;
    document.body.appendChild(a);
    a.addEventListener("click", function(e) {
      a.parentNode.removeChild(a);
    });
    a.click();
  }

  out$.saveSvg = function(el, name, options) {
    requireDomNode(el);

    options = options || {};
    out$.svgAsDataUri(el, options, function(uri) {
      download(name, uri);
    });
  }

  out$.saveSvgAsPng = function(el, name, options) {
    requireDomNode(el);

    options = options || {};
    out$.svgAsPngUri(el, options, function(uri) {
      download(name, uri);
    });
  }

  // if define is defined create as an AMD module
  if (typeof define !== 'undefined') {
    define(function() {
      return out$;
    });
  }
})();