How do I get d3.zoom working for inline svg? - javascript

I am trying to use d3.zoom on an inline svg, specifically a map of the USA (please note that I am very inexperienced at d3js). After some research I found a simple tutorial for using d3.zoom https://www.datamake.io/blog/d3-zoom/.
The issue I have now is that it just doesn't work. There is no error which shows up. It just does nothing.
Here is the HTML code with the svg map.
<div id="map">
<?xml version="1.0" encoding="UTF-8"?>
<svg id="usa_svg" height="800" width="1200" version="1.1" viewBox="0 0 800 600" xmlns="http://www.w3.org/2000/svg">
<g id="USA">
<rect height="600" width="1200"></rect>
<!-- paths here -->
</g>
</svg>
</div>
Here is the JavaScript
var usa = d3.select("svg")
var rect = d3.select("rect");
var zoom = d3.zoom().on("zoom", zoomed);
rect.call(zoom);
function zoomed() {
var transform = d3.event.transform;
usa.attr("transform", transform.toString());
}
I have no clue what I am doing wrong. Is it a syntax error? Am I just missing a vital part of the code? Help would be much appreciated.

Related

I need help understanding how to get s stringified (variable) version of an SVG image

I am currently working with an svg image that I need help stringifying, If that makes sense. Basically how to make the image open in a text/code editor as only variables?
Here is an example of what I am looking for:
var svgData='PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI1MTIiIGhlaWdodD0iNTEyIiB2ZXJzaW9uPSIxLjEiPjxkZWZzPjxsaW5lYXJHcmFkaWVudCBpZD0ic3Ryb2tl
Currently when open an svg image in a text editor I just get something like this.
<?xml version="1.0" encoding="utf-8"?>
<!-- Generator: Adobe Illustrator 22.0.1, SVG Export Plug-In . SVG
Version: 6.00 Build 0) -->
<svg version="1.1" xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="0 0 255.1 227.3" style="enable-background:new 0 0 255.1
227.3;" xml:space="preserve">
<style type="text/css">
Any help is welcome! Thank You.
It looks like svgData is cut a little short. But if I understand your question right, you want that encoded svgData available in a textarea?
You can use the native functions btoa and atob (https://developer.mozilla.org/en-US/docs/Web/API/WindowBase64/Base64_encoding_and_decoding) to encode and decode the svg content.
For example using your svgData value: atob("PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI1MTIiIGhlaWdodD0iNTEyIiB2ZXJzaW9uPSIxLjEiPjxkZWZzPjxsaW5lYXJHcmFkaWVudCBpZD0ic3Ryb2tl") = <svg xmlns="http://www.w3.org/2000/svg" width="512" height="512" version="1.1"><defs><linearGradient id="stroke"
and we can convert it back with:
btoa('<svg xmlns="http://www.w3.org/2000/svg" width="512" height="512" version="1.1"><defs><linearGradient id="stroke"') = "PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI1MTIiIGhlaWdodD0iNTEyIiB2ZXJzaW9uPSIxLjEiPjxkZWZzPjxsaW5lYXJHcmFkaWVudCBpZD0ic3Ryb2tlIg=="

Why is my canvas embedded in an inline SVG not updating?

It seems like a contrived problem but I am trying to make a proof of concept of an HTML 5 document, containing inline SVG, which itself contains a <foreignObject> element with an HTML canvas inside. I then want to call a JavaScript function to draw on the canvas.
(How I got here: I want to use SVG as a format for defining an animated graphical view which can contain graphs, which are animated by replacing a dummy element in the SVG with a live graph using JavaScript / ECMAScript, and one of the JavaScript libraries we are considering to generate the graphs (Flot) uses an HTML canvas for the view, so I want to inject this canvas into the SVG view. A further complication is we ideally want this system to run on local files, on the file:// protocol, meaning we can't run scripts on external files (e.g. referenced with <object> or <iframe>) because browsers block them, hence the inline SVG.)
Here is an HTML source illustrating the problem:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Canvas Test</title>
<script type="text/javascript">
function draw_box() {
var canvas = document.getElementById("box_canvas");
var context = canvas.getContext("2d");
context.fillRect(50, 20, 50, 60);
}
</script>
</head>
<body>
<h1>Canvas Test
<p>
<svg width="400" viewBox="-10 -10 268 108">
<rect style="fill: #a0a0a0" x="8" y="8" width="240" height="80" rx="40" ry="40"/>
<g>
<rect style="fill: #0000ff" x="0" y="0" width="240" height="80" rx="40" ry="40"/>
<rect style="fill: none; fill-opacity:0; stroke-width: 2; stroke-linejoin: round; stroke: #000000" x="0" y="0" width="240" height="80" rx="40" ry="40"/>
<foreignObject x="120" y="25" width="150" height="100">
<canvas id="box_canvas" width="150" height="100" style="border:1px dotted;float:left">Canvas alt text</canvas>
</foreignObject>
</g>
</svg>
<p>
<button type="button" onclick="draw_box();return false">Animate</button>
</body>
</html>
The above page doesn't display the canvas at all in IE 11. In the latest version of Chrome it displays the canvas, but the effects of the JavaScript function called by the button - drawing the black box - only show up if you click on the SVG image.
What I need to know:
1) Is there something wrong with what I've written - e.g. am I missing some function call to make the SVG or foreignObject update after I have drawn on the canvas?
2) Is this a lost cause? Is the specification of <foreignObject> etc. immature enough that I could never be confident that this will work, even if we can control what browser the user views the document in? It's actually fine if this is the case because we can just say going forward that we need our graph library to generate SVG and not HTML.
Thanks a lot

Using an svg object as a container for a Google map

As the title says I have an svg object and I want that object to contain a Google map instance. I was trying to do this the same way I usually do with divs or simple elements, using Javascript and getElementByID and placing the map inside the element. however this does not seem to work here. I have done a lot of searching but since Google uses svg for custom icons and overlays all the responses are related to that. I've mostly tried different approaches regarding where to put the id="map_canvas but nothing has worked.
My HTML with the svg as an object:
<div class="row map">
<div class="span12">
<object type="image/svg+xml" id="map_canvas" data="assets/map/MA_map.svg"></object>
</div>
</div>
My JavaScript (this is currently in the <head> tag but I want to move it to the .js document):
<script>
function initialize() {
var mapCanvas = document.getElementById('map_canvas');
var mapOptions = {
center: new google.maps.LatLng(44.5403, -78.5463),
zoom: 8,
mapTypeId: google.maps.MapTypeId.ROADMAP
}
var map = new google.maps.Map(mapCanvas, mapOptions)
}
google.maps.event.addDomListener(window, 'load', initialize);
</script>
And finally this is what my svg file looks like (created in Illustrator):
<?xml version="1.0" encoding="utf-8"?>
<!-- Generator: Adobe Illustrator 16.0.0, SVG Export Plug-In . SVG Version: 6.00 Build 0) -->
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg version="1.1"
id="map_canvas"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
viewBox="-79.892 94.942 960 599.864"
enable-background="new -79.892 94.942 960 599.864"
xml:space="preserve">
<filter id="dropshadow" height="130%">
<feGaussianBlur in="SourceAlpha" stdDeviation="3"/> <!-- stdDeviation is how much to blur -->
<feOffset dx="2" dy="2" result="offsetblur"/> <!-- how much to offset -->
<feMerge>
<feMergeNode/> <!-- this contains the offset blurred image -->
<feMergeNode in="SourceGraphic"/> <!-- this contains the element that the filter is applied to -->
</feMerge>
</filter>
<path
id="map_canvas"
style="filter:url(#dropshadow)"
<path //lots of lines of code for the path />
</svg>
Possible solutions you can try:
Use an SVG <foreignObject> with a <clipPath> or <mask>. I am not sure how well this will work though.
Use a CSS Mask (http://caniuse.com/#feat=css-masks).
Create a maps Polygon that has the same colour as the background and which is the size of the map and has a hole the shape of your mask.
Cover the map with an <img> (eg. PNG) that has the same colour or texture as the background and which has a hole the shape of your mask.

How to get hammer.js to work with svg files without using jquery?

I am trying to implement the hammer.js with svg files and without using any jquery. I'm trying to use the sample code from the hammer.js site {https://github.com/EightMedia/hammer.js/wiki/Getting-Started}. I have the external javascripts called like this.
<script src="javascript/hammer.js" type="text/javascript"></script>
My javascript is as follows:
<script type="text/javascript">
//<![CDATA[
var element = document.getElementById("testsvg");
var hammertime = Hammer(element).on('doubletap', function(event){
alert("doubletap!");
return false;
}
);
//]]>
</script>
My svg looks like the following.
<svg version="1.1" id="testsvg" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px"
width="585px" height="230" viewBox="0 0 585 230" enable-background="new 0 0 585 230" xml:space="preserve">
<rect x="10" y="10" height="210" width="565" style="stroke:#006600; fill: #00cc00"/>
</svg>
Starting out, I'm just trying to get any detection to work. I do not get any alert when I double tap. I have also tried to implement this with the hammer.fakemultitouch.js plugin on my desktop. Neither the desktop or touch environment do anything.
Anyone have any idea what I might be doing wrongly?
Thanks,
--christopher
First make sure hammer.js is loading correctly. If it is, then you are most likely executing the javascript before the DOM is loaded. The easiest way to fix this is to place your <script> right before the closing </body> tag (near the bottom of your html file). You can also wrap your code in a load event function such as...
window.onload = function(){
var element = document.getElementById("testsvg");
var hammertime = Hammer(element).on('doubletap', function(event){
alert("doubletap!");
return false;
});
}

Accessing a DOM object defined in an external SVG file

SVG standard allows to use and refer external SVG files.
I have a file circle.svg that defines a circle object with id "the_circle".
From the main SVG file I am able to include this circle and animate it, using SVG linking.
I would also like to access the same circle object via javascript, how can I do this ?
What is the javascript equivalent of xlink:href="url(#the_image)#the_circle" ?
Using document.getElementById('the_image') I can only access the SVGImageElement but not the objects defined inside the included SVG.
<?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">
<svg width="100%" height="100%" version="1.1"
xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" >
<image
id="the_image"
x="0" y="0" width="100%" height="100%"
xlink:href="circle.svg" />
<animateTransform
xlink:href="url(#the_image)#the_circle"
attributeName="transform" attributeType="XML"
type="translate"
from="0" to="25"
dur="1s" repeatCount="indefinite"
additive="replace" fill="freeze" />
</svg>
It seems like the "right" way to do this would actually be to use an SVG "use" element, rather than an image. The reason for this is that the DOM interface of the SVG use element specifies a property "instanceRoot", which allows you to get the root of the "instance tree" corresponding to that use element: http://www.w3.org/TR/SVG/struct.html#InterfaceSVGUseElement
So, you would end up with a solution that looks something like the following:
circle.svg:
<?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">
<svg width="4in" height="4in" id="the_svg"
viewBox="0 0 4 4" version="1.1"
xmlns="http://www.w3.org/2000/svg">
<circle r="1" fill="blue" stroke="none" id="the_circle"/>
</svg>
Document which uses the svg root node of circle.svg:
<?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">
<svg width="100%" height="100%" id="foo"
version="1.1"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">
<use xlink:href="circle.svg#the_svg"/>
</svg>
Unfortunately, though, while Firefox supports use of the use element with external documents, there's currently a bug in Webkit which does not allow this: https://bugs.webkit.org/show_bug.cgi?id=12499
Also, Firefox does not seem to implement the instanceRoot property for use elements.
So, it seems you may need to work around the limitations of current SVG implementations. The way I would recommend doing this is to use XMLHttpRequest to download the document to which you would like to link, and import the DOM of the downloaded document into your host document's DOM. The following code implements this, and works in Firefox, Opera and Chromium:
<?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">
<svg width="100%" height="100%" id="foo"
version="1.1"
xmlns="http://www.w3.org/2000/svg"
xmlns:xlink="http://www.w3.org/1999/xlink">
<script>
function fetchXML (url, callback) {
var xhr = new XMLHttpRequest();
xhr.open('GET', url, true);
xhr.onreadystatechange = function (evt) {
//Do not explicitly handle errors, those should be
//visible via console output in the browser.
if (xhr.readyState === 4) {
callback(xhr.responseXML);
}
};
xhr.send(null);
};
//fetch the document
fetchXML("http://localhost:8082/tmp/circle.svg",function(newSVGDoc){
//import it into the current DOM
var n = document.importNode(newSVGDoc.documentElement,true);
document.documentElement.appendChild(n);
var circle = document.getElementById("the_circle"); //now you have the circle
})
</script>
</svg>
You can access the necessary element a bit easier:
document.getElementById('the_image').contentDocument.getElementById('the_circle')
See this image for reference (taken on dev.opera.com)
To supplement #echo-flow's excellent solution with the code in jQuery/Coffeescript:
$.get '/assets/hexagon.svg', (svgFileData)->
svgTag = svgFileData.documentElement
$('body').append(svgTag)
circle = $('#the_circle')
Here's a solution to this problem when using React and ES6. Usage:
<SvgImage url='pathToImage.svg'></SvgImage>
https://gist.github.com/mikkel/8b79a713ff06bbec379d

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