Is there a way to just generate an svg and get it as a string without actually drawing it? I thought about render svg to a hidden div and then reading the inner html, but is there a cleaner way?
I would think you could do this:
var svg = d3.select("body").append("svg")
svg = d3.select(svg).remove()
Append the svg to the body, but immediately remove it. This will, of course, give you the 'd3 selection' object, not a string.
You can create a whole other DOM tree in javascript using createDocumentFragment(). This is commonly used to create a complex section of the document and then add it all to the page in one step, so the browser only has to re-calculate layout once.
I haven't tested it, but you should also be able to use .innerHTML() to extract everything you've created as a string that can be saved to file. Answers to this SO Question suggest that you can't call innerHTML() directly on the document fragment itself, so you would have to add a body element to the fragment, add your SVG to it, and then get the inner HTML from the body node.
One way to approach this problem is by checking how it would be done on the server side -- where there is no DOM.
As it turns out, the way to do this on the server side involves more or less the same "hack" used in the question. This is because d3 expects to work on a DOM; writing that DOM to HTML is really the only way to render it to a string.
Brief example:
var svg = window.d3.select('body')
.append('div').attr('class','container')
.append('svg'); // and lots of other stuff
//etc etc
svg.selectAll('.arc').doSomething('blah blah');
var svgAsString = d3.select('.container').html();
Related
In tutorials I've learnt to use document.write. Now I understand that by many this is frowned upon. I've tried print(), but then it literally sends it to the printer.
So what are alternatives I should use, and why shouldn't I use document.write? Both w3schools and MDN use document.write.
The reason that your HTML is replaced is because of an evil JavaScript function: document.write().
It is most definitely "bad form." It only works with webpages if you use it on the page load; and if you use it during runtime, it will replace your entire document with the input. And if you're applying it as strict XHTML structure it's not even valid code.
the problem:
document.write writes to the document stream. Calling document.write on a closed (or loaded) document automatically calls document.open which will clear the document.
-- quote from the MDN
document.write() has two henchmen, document.open(), and document.close(). When the HTML document is loading, the document is "open". When the document has finished loading, the document has "closed". Using document.write() at this point will erase your entire (closed) HTML document and replace it with a new (open) document. This means your webpage has erased itself and started writing a new page - from scratch.
I believe document.write() causes the browser to have a performance decrease as well (correct me if I am wrong).
an example:
This example writes output to the HTML document after the page has loaded. Watch document.write()'s evil powers clear the entire document when you press the "exterminate" button:
I am an ordinary HTML page. I am innocent, and purely for informational purposes. Please do not <input type="button" onclick="document.write('This HTML page has been succesfully exterminated.')" value="exterminate"/>
me!
the alternatives:
.innerHTML This is a wonderful alternative, but this attribute has to be attached to the element where you want to put the text.
Example: document.getElementById('output1').innerHTML = 'Some text!';
.createTextNode() is the alternative recommended by the W3C.
Example: var para = document.createElement('p');
para.appendChild(document.createTextNode('Hello, '));
NOTE: This is known to have some performance decreases (slower than .innerHTML). I recommend using .innerHTML instead.
the example with the .innerHTML alternative:
I am an ordinary HTML page.
I am innocent, and purely for informational purposes.
Please do not
<input type="button" onclick="document.getElementById('output1').innerHTML = 'There was an error exterminating this page. Please replace <code>.innerHTML</code> with <code>document.write()</code> to complete extermination.';" value="exterminate"/>
me!
<p id="output1"></p>
Here is code that should replace document.write in-place:
document.write=function(s){
var scripts = document.getElementsByTagName('script');
var lastScript = scripts[scripts.length-1];
lastScript.insertAdjacentHTML("beforebegin", s);
}
You can combine insertAdjacentHTML method and document.currentScript property.
The insertAdjacentHTML() method of the Element interface parses the specified text as HTML or XML and inserts the resulting nodes into the DOM tree at a specified position:
'beforebegin': Before the element itself.
'afterbegin': Just inside the element, before its first child.
'beforeend': Just inside the element, after its last child.
'afterend': After the element itself.
The document.currentScript property returns the <script> element whose script is currently being processed. Best position will be beforebegin — new HTML will be inserted before <script> itself. To match document.write's native behavior, one would position the text afterend, but then the nodes from consecutive calls to the function aren't placed in the same order as you called them (like document.write does), but in reverse. The order in which your HTML appears is probably more important than where they're place relative to the <script> tag, hence the use of beforebegin.
document.currentScript.insertAdjacentHTML(
'beforebegin',
'This is a document.write alternative'
)
As a recommended alternative to document.write you could use DOM manipulation to directly query and add node elements to the DOM.
Just dropping a note here to say that, although using document.write is highly frowned upon due to performance concerns (synchronous DOM injection and evaluation), there is also no actual 1:1 alternative if you are using document.write to inject script tags on demand.
There are a lot of great ways to avoid having to do this (e.g. script loaders like RequireJS that manage your dependency chains) but they are more invasive and so are best used throughout the site/application.
I fail to see the problem with document.write. If you are using it before the onload event fires, as you presumably are, to build elements from structured data for instance, it is the appropriate tool to use. There is no performance advantage to using insertAdjacentHTML or explicitly adding nodes to the DOM after it has been built. I just tested it three different ways with an old script I once used to schedule incoming modem calls for a 24/7 service on a bank of 4 modems.
By the time it is finished this script creates over 3000 DOM nodes, mostly table cells. On a 7 year old PC running Firefox on Vista, this little exercise takes less than 2 seconds using document.write from a local 12kb source file and three 1px GIFs which are re-used about 2000 times. The page just pops into existence fully formed, ready to handle events.
Using insertAdjacentHTML is not a direct substitute as the browser closes tags which the script requires remain open, and takes twice as long to ultimately create a mangled page. Writing all the pieces to a string and then passing it to insertAdjacentHTML takes even longer, but at least you get the page as designed. Other options (like manually re-building the DOM one node at a time) are so ridiculous that I'm not even going there.
Sometimes document.write is the thing to use. The fact that it is one of the oldest methods in JavaScript is not a point against it, but a point in its favor - it is highly optimized code which does exactly what it was intended to do and has been doing since its inception.
It's nice to know that there are alternative post-load methods available, but it must be understood that these are intended for a different purpose entirely; namely modifying the DOM after it has been created and memory allocated to it. It is inherently more resource-intensive to use these methods if your script is intended to write the HTML from which the browser creates the DOM in the first place.
Just write it and let the browser and interpreter do the work. That's what they are there for.
PS: I just tested using an onload param in the body tag and even at this point the document is still open and document.write() functions as intended. Also, there is no perceivable performance difference between the various methods in the latest version of Firefox. Of course there is a ton of caching probably going on somewhere in the hardware/software stack, but that's the point really - let the machine do the work. It may make a difference on a cheap smartphone though. Cheers!
The question depends on what you are actually trying to do.
Usually, instead of doing document.write you can use someElement.innerHTML or better, document.createElement with an someElement.appendChild.
You can also consider using a library like jQuery and using the modification functions in there: http://api.jquery.com/category/manipulation/
This is probably the most correct, direct replacement: insertAdjacentHTML.
Try to use getElementById() or getElementsByName() to access a specific element and then to use innerHTML property:
<html>
<body>
<div id="myDiv1"></div>
<div id="myDiv2"></div>
</body>
<script type="text/javascript">
var myDiv1 = document.getElementById("myDiv1");
var myDiv2 = document.getElementById("myDiv2");
myDiv1.innerHTML = "<b>Content of 1st DIV</b>";
myDiv2.innerHTML = "<i>Content of second DIV element</i>";
</script>
</html>
Use
var documentwrite =(value, method="", display="")=>{
switch(display) {
case "block":
var x = document.createElement("p");
break;
case "inline":
var x = document.createElement("span");
break;
default:
var x = document.createElement("p");
}
var t = document.createTextNode(value);
x.appendChild(t);
if(method==""){
document.body.appendChild(x);
}
else{
document.querySelector(method).appendChild(x);
}
}
and call the function based on your requirement as below
documentwrite("My sample text"); //print value inside body
documentwrite("My sample text inside id", "#demoid", "block"); // print value inside id and display block
documentwrite("My sample text inside class", ".democlass","inline"); // print value inside class and and display inline
I'm not sure if this will work exactly, but I thought of
var docwrite = function(doc) {
document.write(doc);
};
This solved the problem with the error messages for me.
html2pdf.js is a package for generating pdf's from html it is based on jspdf and html2canvas. It has a nice feature where it can insert page-breaks in order not to split elements. The way it works is that it loops over all the elements and creates empty div's where a page break needs to be inserted. I would like to style those divs and instead of having blank white space would like to be able to insert a class to determine how they would look. The issue is I don't seem to have access to this new HTML that will be converted to a pdf. The API seems to indicate that this is possible here but when I put in code like this:
var worker = html2pdf();
worker.set(opt).from(finalHtml).toContainer().toCanvas().then(newHtml => {
console.log(newHtml)
return newHtml
})
I am getting undefined. This is true whether I chain to toCanvas() and toContainer or not. Basically I would like the html generated here, how do I access this?
I am trying to move an svg from one div to another. This stack question offered this solution which I tried.
document.getElementById("LightBoxDiv").appendChild(svgId+"V");
When I tried this, I received an hierarchy request error. This stack question suggested several things which might be the cause. I cannot tell that I have any of those things, but am not sure. Bot my div's are in the body element and are not nested within one another, however, one of the div's was only a few lines before created dynamically with javascript. Here's the script I am using to create that div.
var lightboxdiv = document.createElement('div');
lightboxdiv.id = "LightBoxDiv";
document.body.appendChild(lightboxdiv);
document.getElementById("LightBoxDiv").style.display="block";
document.getElementById("LightBoxDiv").style.position="fixed";
document.getElementById("LightBoxDiv").style.overflow="hidden";
document.getElementById("LightBoxDiv").style.padding="5%";
document.getElementById("LightBoxDiv").style.top=0;
document.getElementById("LightBoxDiv").style.left=0;
document.getElementById("LightBoxDiv").style.width="100%";
document.getElementById("LightBoxDiv").style.height="100%";
document.getElementById("LightBoxDiv").style.background="white";
document.getElementById("LightBoxDiv").style.zIndex="1001";
document.getElementById("LightBoxDiv").setAttribute("class","dotouch");
document.getElementById("LightBoxDiv").appendChild(svgId+"V");
The last line is the one that throws the error. Any idea what I've done to cause the error? How might I go about fixing it.
Thanks, --christopher
You're mixing jQuery code with standard DOM API.
The function appendChild() expects a DOM node, not an Element ID. Try
var svg = document.getElementById(svgId+"V");
document.getElementById("LightBoxDiv").appendChild(svg);
const lightboxdiv = document.getElementById("LightBoxDiv");
Why strain the user's browser 12 times to search for an element in a document id that is already stored in a variable?
lightboxdiv.style.display = ...;
lightboxdiv.style.position = ...;
I think it would work much
I ran into this same error, except I'm not using JQuery.
The problem I found, was that the element i was trying to move from one Div to another, was invisible (that is, its style display = 'none').
First by removing this style and then appending it, solved the problem for me.
I'm developing a little tool for live editing using Chrome DevTools, and I have a little button "Save" which grabs the HTML and sends it to server to update the static file (.html) using Ajax. Very simple indeed.
My problem is that I need to filter the HTML code before sending it to the server, I need to remove some nodes and I'm trying to achive this using jQuery, something like this:
// I grab all the HTML code
var html = $('<div>').append($('html').clone()).html();
// Now I need to remove some nodes using jQuery
$(html).find('#some-node').remove();
// Send the filtered HTML to server
$.post('url/to/server/blahblahblah');
I already tried this Using jQuery to search a string of HTML with no success. I can't achieve to use jQuery on my cloned HTML code.
Any idea about how to do this?
The DOM is not a string of HTML. With jQuery, you do DOM manipulation, not string manipulation.
What you're doing is
cloning the document (unnecessary because you convert it to HTML anyway),
appending that cloned document to a new div for some reason
converting the content of that div to an HTML string
converting that HTML back to DOM nodes $(html) (so we're back to the first point above)
finding and removing an element in those nodes
presumably posting the html variable to the server.
Unfortunately, the html string has not changed because you manipulated DOM nodes, not the string.
Hopefully you can see above that you're doing all sorts of conversions that have little to do with what you ultimately want.
I don't know wny you'd need to do this, but all you need is to do a .clone(), then the .find().remove(), then .html()
var result = $("html").clone(false);
result.find("#some-node").remove();
var html = result.html();
Maybe like this?
var html = $('html').clone();
html.find('#some-node').remove();
In tutorials I've learnt to use document.write. Now I understand that by many this is frowned upon. I've tried print(), but then it literally sends it to the printer.
So what are alternatives I should use, and why shouldn't I use document.write? Both w3schools and MDN use document.write.
The reason that your HTML is replaced is because of an evil JavaScript function: document.write().
It is most definitely "bad form." It only works with webpages if you use it on the page load; and if you use it during runtime, it will replace your entire document with the input. And if you're applying it as strict XHTML structure it's not even valid code.
the problem:
document.write writes to the document stream. Calling document.write on a closed (or loaded) document automatically calls document.open which will clear the document.
-- quote from the MDN
document.write() has two henchmen, document.open(), and document.close(). When the HTML document is loading, the document is "open". When the document has finished loading, the document has "closed". Using document.write() at this point will erase your entire (closed) HTML document and replace it with a new (open) document. This means your webpage has erased itself and started writing a new page - from scratch.
I believe document.write() causes the browser to have a performance decrease as well (correct me if I am wrong).
an example:
This example writes output to the HTML document after the page has loaded. Watch document.write()'s evil powers clear the entire document when you press the "exterminate" button:
I am an ordinary HTML page. I am innocent, and purely for informational purposes. Please do not <input type="button" onclick="document.write('This HTML page has been succesfully exterminated.')" value="exterminate"/>
me!
the alternatives:
.innerHTML This is a wonderful alternative, but this attribute has to be attached to the element where you want to put the text.
Example: document.getElementById('output1').innerHTML = 'Some text!';
.createTextNode() is the alternative recommended by the W3C.
Example: var para = document.createElement('p');
para.appendChild(document.createTextNode('Hello, '));
NOTE: This is known to have some performance decreases (slower than .innerHTML). I recommend using .innerHTML instead.
the example with the .innerHTML alternative:
I am an ordinary HTML page.
I am innocent, and purely for informational purposes.
Please do not
<input type="button" onclick="document.getElementById('output1').innerHTML = 'There was an error exterminating this page. Please replace <code>.innerHTML</code> with <code>document.write()</code> to complete extermination.';" value="exterminate"/>
me!
<p id="output1"></p>
Here is code that should replace document.write in-place:
document.write=function(s){
var scripts = document.getElementsByTagName('script');
var lastScript = scripts[scripts.length-1];
lastScript.insertAdjacentHTML("beforebegin", s);
}
You can combine insertAdjacentHTML method and document.currentScript property.
The insertAdjacentHTML() method of the Element interface parses the specified text as HTML or XML and inserts the resulting nodes into the DOM tree at a specified position:
'beforebegin': Before the element itself.
'afterbegin': Just inside the element, before its first child.
'beforeend': Just inside the element, after its last child.
'afterend': After the element itself.
The document.currentScript property returns the <script> element whose script is currently being processed. Best position will be beforebegin — new HTML will be inserted before <script> itself. To match document.write's native behavior, one would position the text afterend, but then the nodes from consecutive calls to the function aren't placed in the same order as you called them (like document.write does), but in reverse. The order in which your HTML appears is probably more important than where they're place relative to the <script> tag, hence the use of beforebegin.
document.currentScript.insertAdjacentHTML(
'beforebegin',
'This is a document.write alternative'
)
As a recommended alternative to document.write you could use DOM manipulation to directly query and add node elements to the DOM.
Just dropping a note here to say that, although using document.write is highly frowned upon due to performance concerns (synchronous DOM injection and evaluation), there is also no actual 1:1 alternative if you are using document.write to inject script tags on demand.
There are a lot of great ways to avoid having to do this (e.g. script loaders like RequireJS that manage your dependency chains) but they are more invasive and so are best used throughout the site/application.
I fail to see the problem with document.write. If you are using it before the onload event fires, as you presumably are, to build elements from structured data for instance, it is the appropriate tool to use. There is no performance advantage to using insertAdjacentHTML or explicitly adding nodes to the DOM after it has been built. I just tested it three different ways with an old script I once used to schedule incoming modem calls for a 24/7 service on a bank of 4 modems.
By the time it is finished this script creates over 3000 DOM nodes, mostly table cells. On a 7 year old PC running Firefox on Vista, this little exercise takes less than 2 seconds using document.write from a local 12kb source file and three 1px GIFs which are re-used about 2000 times. The page just pops into existence fully formed, ready to handle events.
Using insertAdjacentHTML is not a direct substitute as the browser closes tags which the script requires remain open, and takes twice as long to ultimately create a mangled page. Writing all the pieces to a string and then passing it to insertAdjacentHTML takes even longer, but at least you get the page as designed. Other options (like manually re-building the DOM one node at a time) are so ridiculous that I'm not even going there.
Sometimes document.write is the thing to use. The fact that it is one of the oldest methods in JavaScript is not a point against it, but a point in its favor - it is highly optimized code which does exactly what it was intended to do and has been doing since its inception.
It's nice to know that there are alternative post-load methods available, but it must be understood that these are intended for a different purpose entirely; namely modifying the DOM after it has been created and memory allocated to it. It is inherently more resource-intensive to use these methods if your script is intended to write the HTML from which the browser creates the DOM in the first place.
Just write it and let the browser and interpreter do the work. That's what they are there for.
PS: I just tested using an onload param in the body tag and even at this point the document is still open and document.write() functions as intended. Also, there is no perceivable performance difference between the various methods in the latest version of Firefox. Of course there is a ton of caching probably going on somewhere in the hardware/software stack, but that's the point really - let the machine do the work. It may make a difference on a cheap smartphone though. Cheers!
The question depends on what you are actually trying to do.
Usually, instead of doing document.write you can use someElement.innerHTML or better, document.createElement with an someElement.appendChild.
You can also consider using a library like jQuery and using the modification functions in there: http://api.jquery.com/category/manipulation/
This is probably the most correct, direct replacement: insertAdjacentHTML.
Try to use getElementById() or getElementsByName() to access a specific element and then to use innerHTML property:
<html>
<body>
<div id="myDiv1"></div>
<div id="myDiv2"></div>
</body>
<script type="text/javascript">
var myDiv1 = document.getElementById("myDiv1");
var myDiv2 = document.getElementById("myDiv2");
myDiv1.innerHTML = "<b>Content of 1st DIV</b>";
myDiv2.innerHTML = "<i>Content of second DIV element</i>";
</script>
</html>
Use
var documentwrite =(value, method="", display="")=>{
switch(display) {
case "block":
var x = document.createElement("p");
break;
case "inline":
var x = document.createElement("span");
break;
default:
var x = document.createElement("p");
}
var t = document.createTextNode(value);
x.appendChild(t);
if(method==""){
document.body.appendChild(x);
}
else{
document.querySelector(method).appendChild(x);
}
}
and call the function based on your requirement as below
documentwrite("My sample text"); //print value inside body
documentwrite("My sample text inside id", "#demoid", "block"); // print value inside id and display block
documentwrite("My sample text inside class", ".democlass","inline"); // print value inside class and and display inline
I'm not sure if this will work exactly, but I thought of
var docwrite = function(doc) {
document.write(doc);
};
This solved the problem with the error messages for me.