How can I show HTML snippets on a webpage without needing to replace each < with < and > with >?
In other words, is there a tag for don't render HTML until you hit the closing tag?
The tried and true method for HTML:
Replace the & character with &
Replace the < character with <
Replace the > character with >
Optionally surround your HTML sample with <pre> and/or <code> tags.
sample 1:
<pre>
This text has
been formatted using
the HTML pre tag. The brower should
display all white space
as it was entered.
</pre>
sample 2:
<pre>
<code>
My pre-formatted code
here.
</code>
</pre>
sample 3:
(If you are actually "quoting" a block of code, then the markup would be)
<blockquote>
<pre>
<code>
My pre-formatted "quoted" code here.
</code>
</pre>
</blockquote>
is there a tag for don't render HTML until you hit the closing tag?
No, there is not. In HTML proper, there’s no way short of escaping some characters:
& as &
< as <
(Incidentally, there is no need to escape > but people often do it for reasons of symmetry.)
And of course you should surround the resulting, escaped HTML code within <pre><code>…</code></pre> to (a) preserve whitespace and line breaks, and (b) mark it up as a code element.
All other solutions, such as wrapping your code into a <textarea> or the (deprecated) <xmp> element, will break.1
XHTML that is declared to the browser as XML (via the HTTP Content-Type header! — merely setting a DOCTYPE is not enough) could alternatively use a CDATA section:
<![CDATA[Your <code> here]]>
But this only works in XML, not in HTML, and even this isn’t a foolproof solution, since the code mustn’t contain the closing delimiter ]]>. So even in XML the simplest, most robust solution is via escaping.
1 Case in point:
textarea {border: none; width: 100%;}
<textarea readonly="readonly">
<p>Computer <textarea>says</textarea> <span>no.</span>
</textarea>
<xmp>
Computer <xmp>says</xmp> <span>no.</span>
</xmp>
Kind of a naive method to display code will be including it in a textarea and add disabled attribute so its not editable.
<textarea disabled> code </textarea>
Hope that help someone looking for an easy way to get stuff done.
But warning, this won't escape the tags for you, as you can see here (the following obviously does not work):
<textarea disabled>
This is the code to create a textarea:
<textarea></textarea>
</textarea>
Deprecated, but works in FF3 and IE8.
<xmp>
<b>bold</b><ul><li>list item</li></ul>
</xmp>
Recommended:
<pre><code>
code here, escape it yourself.
</code></pre>
i used <xmp> just like this :
http://jsfiddle.net/barnameha/hF985/1/
The deprecated <xmp> tag essentially does that but is no longer part of the XHTML spec. It should still work though in all current browsers.
Here's another idea, a hack/parlor trick, you could put the code in a textarea like so:
<textarea disabled="true" style="border: none;background-color:white;">
<p>test</p>
</textarea>
Putting angle brackets and code like this inside a text area is invalid HTML and will cause undefined behavior in different browsers. In Internet Explorer the HTML is interpreted, whereas Mozilla, Chrome and Safari leave it uninterpreted.
If you want it to be non-editable and look different then you could easily style it using CSS. The only issue would be that browsers will add that little drag handle in the bottom-right corner to resize the box. Or alternatively, try using an input tag instead.
The right way to inject code into your textarea is to use server side language like this PHP for example:
<textarea disabled="true" style="border: none;background-color:white;">
<?php echo '<p>test</p>'; ?>
</textarea>
Then it bypasses the html interpreter and puts uninterpreted text into the textarea consistently across all browsers.
Other than that, the only way is really to escape the code yourself if static HTML or using server-side methods such as .NET's HtmlEncode() if using such technology.
If your goal is to show a chunk of code that you're executing elsewhere on the same page, you can use textContent (it's pure-js and well supported: http://caniuse.com/#feat=textcontent)
<div id="myCode">
<p>
hello world
</p>
</div>
<div id="loadHere"></div>
document.getElementById("myCode").textContent = document.getElementById("loadHere").innerHTML;
To get multi-line formatting in the result, you need to set css style "white-space: pre;" on the target div, and write the lines individually using "\r\n" at the end of each.
Here's a demo: https://jsfiddle.net/wphps3od/
This method has an advantage over using textarea: Code wont be reformatted as it would in a textarea. (Things like are removed entirely in a textarea)
In HTML? No.
In XML/XHTML? You could use a CDATA block.
I assume:
you want to write 100% valid HTML5
you want to place the code snippet (almost) literal in the HTML
especially < should not need escaping
All your options are in this tree:
with HTML syntax
there are five kinds of elements
those called "normal elements" (like <p>)
can't have a literal <
it would be considered the start of the next tag or comment
void elements
they have no content
you could put your HTML in a data attribute (but this is true for all elements)
that would need JavaScript to move the data elsewhere
in double-quoted attributes, " and &thing; need escaping: " and &thing; respectively
raw text elements
<script> and <style> only
they are never rendered visible
but embedding your text in Javascript might be feasable
Javascript allows for multi-line strings with backticks
it could then be inserted dynamically
a literal </script is not allowed anywhere in <script>
escapable raw text elements
<textarea> and <title> only
<textarea> is a good candidate to wrap code in
it is totally legal to write </html> in there
not legal is the substring </textarea for obvious reasons
escape this special case with </textarea or similar
&thing; needs escaping: &thing;
foreign elements
elements from MathML and SVG namespaces
at least SVG allows embedding of HTML again...
and CDATA is allowed there, so it seems to have potential
with XML syntax
covered by Konrad's answer
Note: > never needs escaping. Not even in normal elements.
It's vey simple ....
Use this xmp code
<xmp id="container">
<xmp >
<p>a paragraph</p>
</xmp >
</xmp>
<textarea ><?php echo htmlentities($page_html); ?></textarea>
works fine for me..
"keeping in mind Alexander's suggestion, here is why I think this is a good approach"
if we just try plain <textarea> it may not always work since there may be closing textarea tags which may wrongly close the parent tag and display rest of the HTML source on the parent document, which would look awkward.
using htmlentities converts all applicable characters such as < > to HTML entities which eliminates any possibility of leaks.
There maybe benefits or shortcomings to this approach or a better way of achieving the same results, if so please comment as I would love to learn from them :)
This is a simple trick and I have tried it in Safari and Firefox
<code>
<span><</span>meta property="og:title" content="A very fine cuisine" /><br>
<span><</span>meta property="og:image" content="http://www.example.com/image.png" />
</code>
It will show like this:
You can see it live Here
You could try:
Hello! Here is some code:
<xmp>
<div id="hello">
</div>
</xmp>
This is a bit of a hack, but we can use something like:
body script {
display: block;
font-family: monospace;
white-space: pre;
}
<script type="text/html">
<h1>Hello World</h1>
<ul>
<li>Enjoy this dodgy hack,
<li>or don't!
</ul>
</script>
With that CSS, the browser will display scripts inside the body. It won’t attempt to execute this script, as it has an unknown type text/html. It’s not necessary to escape special characters inside a <script>, unless you want to include a closing </script> tag.
I’m using something like this to display executable JavaScript in the body of the page, for a sort of "literate progamming".
There’s some more info in this question When should tags be visible and why can they?.
function escapeHTML(string)
{
var pre = document.createElement('pre');
var text = document.createTextNode(string);
pre.appendChild(text);
return pre.innerHTML;
}//end escapeHTML
it will return the escaped Html
Ultimately the best (though annoying) answer is "escape the text".
There are however a lot of text editors -- or even stand-alone mini utilities -- that can do this automatically. So you never should have to escape it manually if you don't want to (Unless it's a mix of escaped and un-escaped code...)
Quick Google search shows me this one, for example: http://malektips.com/zzee-text-utility-html-escape-regular-expression.html
This is by far the best method for most situations:
<pre><code>
code here, escape it yourself.
</code></pre>
I would have up voted the first person who suggested it but I don't have reputation. I felt compelled to say something though for the sake of people trying to find answers on the Internet.
You could use a server side language like PHP to insert raw text:
<?php
$str = <<<EOD
<html lang="en">
<head>
<meta charset="utf-8">
<meta name="description" content="Minimal HTML5">
<meta name="keywords" content="HTML5,Minimal">
<title>This is the title</title>
<link rel='stylesheet.css' href='style.css'>
</head>
<body>
</body>
</html>
EOD;
?>
then dump out the value of $str htmlencoded:
<div style="white-space: pre">
<?php echo htmlentities($str); ?>
</div>
There are a few ways to escape everything in HTML, none of them nice.
Or you could put in an iframe that loads a plain old text file.
Actually there is a way to do this. It has limitation (one), but is 100% standard, not deprecated (like xmp), and works.
And it's trivial. Here it is:
<div id="mydoc-src" style="display: none;">
LlNnlljn77fggggkk77csJJK8bbJBKJBkjjjjbbbJJLJLLJo
<!--
YOUR CODE HERE.
<script src="WidgetsLib/all.js"></script>
^^ This is a text, no side effects trying to load it.
-->
LlNnlljn77fggggkk77csJJK8bbJBKJBkjjjjbbbJJLJLLJo
</div>
Please let me explain. First of all, ordinary HTML comment does the job, to prevent whole block be interpreted. You can easily add in it any tags, all of them will be ignored. Ignored from interpretation, but still available via innerHTML! So what is left, is to get the contents, and filter the preceding and trailing comment tokens.
Except (remember - the limitation) you can't put there HTML comments inside, since (at least in my Chrome) nesting of them is not supported, and very first '-->' will end the show.
Well, it is a nasty little limitation, but in certain cases it's not a problem at all, if your text is free of HTML comments. And, it's easier to escape one construct, then a whole bunch of them.
Now, what is that weird LlNnlljn77fggggkk77csJJK8bbJBKJBkjjjjbbbJJLJLLJo string? It's a random string, like a hash, unlikely to be used in the block, and used for? Here's the context, why I have used it. In my case, I took the contents of one DIV, then processed it with Showdown markdown, and then the output assigned into another div. The idea was, to write markdown inline in the HTML file, and just open in a browser and it would transform on the load on-the-fly. So, in my case, <!-- became transformed to <p><!--</p>, the comment properly escaped. It worked, but polluted the screen. So, to easily remove it with regex, the random string was used. Here's the code:
var converter = new showdown.Converter();
converter.setOption('simplifiedAutoLink', true);
converter.setOption('tables', true);
converter.setOption('tasklists', true);
var src = document.getElementById("mydoc-src");
var res = document.getElementById("mydoc-res");
res.innerHTML = converter.makeHtml(src.innerHTML)
.replace(/<p>.{0,10}LlNnlljn77fggggkk77csJJK8bbJBKJBkjjjjbbbJJLJLLJo.{0,10}<\/p>/g, "");
src.innerHTML = '';
And it works.
If somebody is interested, this article is written using this technique. Feel free to download, and look inside the HTML file.
It depends what you are using it for. Is it user input? Then use <textarea>, and escape everything. In my case, and probably it's your case too, I simply used comments, and it does the job.
If you don't use markdown, and just want to get it as is from a tag, then it's even simpler:
<div id="mydoc-src" style="display: none;">
<!--
YOUR CODE HERE.
<script src="WidgetsLib/all.js"></script>
^^ This is a text, no side effects trying to load it.
-->
</div>
and JavaScript code to get it:
var src = document.getElementById("mydoc-src");
var YOUR_CODE = src.innerHTML.replace(/(<!--|-->)/g, "");
This is how I did it:
$str = file_get_contents("my-code-file.php");
echo "<textarea disabled='true' style='border: none;background-color:white;'>";
echo $str;
echo "</textarea>";
It may not work in every situation, but placing code snippets inside of a textarea will display them as code.
You can style the textarea with CSS if you don't want it to look like an actual textarea.
If you are looking for a solution that works with frameworks.
const code = `
<div>
this will work in react
<div>
`
<pre>
<code>{code}</code>
</pre>
And you can give it a nice look with css:
pre code {
background-color: #eee;
border: 1px solid #999;
display: block;
padding: 20px;
}
JavaScript string literals can be used to write the HTML across multiple lines. Obviously, JavaScript, ECMA6 in particular, is required for this solution.
.createTextNode paired with CSS white-space: pre-wrap; does the trick.
.innerText alone also works. Run code snippet below.
let codeBlock = `
<!DOCTYPE HTML>
<html lang="en">
<head>
<title>My Page</title>
</head>
<body>
<h1>Welcome to my page</h1>
<p>I like cars and lorries and have a big Jeep!</p>
<h2>Where I live</h2>
<p>I live in a small hut on a mountain!</p>
</body>
</html>
`
const codeElement = document.querySelector("#a");
let textNode = document.createTextNode(codeBlock);
codeElement.appendChild(textNode);
const divElement = document.querySelector("#b");
divElement.innerText = codeBlock;
#a {
white-space: pre-wrap;
}
<div id=a>
</div>
<div id=b>
</div>
//To show xml tags in table columns you will have to encode the tags first
function htmlEncode(value) {
//create a in-memory div, set it's inner text(which jQuery automatically encodes)
//then grab the encoded contents back out. The div never exists on the page.
return $('<div/>').text(value).html();
}
html = htmlEncode(html)
A combination of a couple answers that work together here:
function c(s) {
return s.split("<").join("<").split(">").join(">").split("&").join("&")
}
displayMe.innerHTML = ok.innerHTML;
console.log(
c(ok.innerHTML)
)
<textarea style="display:none" id="ok">
<script>
console.log("hello", 5&9);
</script>
</textarea>
<div id="displayMe">
</div>
I used this a long time ago and it did the trick for me, I hope it helps you too.
var preTag = document.querySelectorAll('pre');
console.log(preTag.innerHTML);
for (var i = 0; i < preTag.length; i++) {
var pattern = preTag[i].innerHTML;
pattern = pattern.replace(/</g, "<").replace(/>/g, ">");
console.log(pattern);
preTag[i].innerHTML = pattern;
}
<pre>
<p>example</p>
<span>more text</span>
</pre>
You can separate the tags by changing them to spans.
Like this:
<span><</span> <!-- opening bracket of h1 here -->
<span>h1></span> <!-- opening tag of h1 completed here -->
<span>hello</span> <!-- text to print -->
<span><</span> <!-- closing h1 tag's bracket here -->
<span>/h1></span> <!-- closing h1 tag ends here -->
And also, you can just only add the <(opening angle bracket) to the spans
<span><</span> <!-- opening bracket of h1 here -->
h1> <!-- opening tag of h1 completed here -->
hello <!-- text to print -->
<span><</span> <!-- closing h1 tag's bracket here -->
/h1><!-- closing h1 tag ends here -->
<code><?php $str='<';echo htmlentities($str);?></code>
I found this to be the easiest, fastest and most compact.
I am looking for an easy way to insert content at the top of the <body> section in a WordPress plugin, and discovered that there is no core hook to do this, and I can't rely on modifying the theme. However there is a hook to insert in to the <head> section, and I discovered that if I insert the <div> into the <head> section rather than the <body>, all browsers I've tested will in fact move that content from the <head> to the top of the <body> section which is just what I want.
I know this fails W3C validation which is bad, on the other hand most sites have W3C validation errors. And more importantly, this trick works on Chrome, FF, IE, Safari, Android, and iPhone, Chrome mobile, Brave mobile, Ghostery mobile, to name a few places I've checked.
Will this kind of code cause problems in practice? Should I avoid doing this and find another way?
Run this HTML code and you'll see both DIVs in the body after the page renders:
<html>
<head>
<div>This is the head</div>
</head>
<body>
<div>This is the body</div>
</body>
</html>
And here's what you'll see in your browser:
Updated Answer
So you have some pretty strict requirements:
No theme editing (initiated via plugin)
No JavaScript insert (needs to be in initial DOM)
If you just need to have the element high on the page, you could stick it on a relatively early hook, and then move it after <body> with JavaScript.
If it needs to be one of the first things loaded, you probably could just stick it in the wp_head - making sure it's just got a really low priority so it makes quasi-semantic sense.
However you could also insert it with PHP using a real-time find and replace. You shouldn't suffer too much of a performance hit, but something like this would get you started:
function Danger_insert_iframe( $buffer ){
// Define your iframe
$iframe = '<iframe src="https://xhynk.com" style="width: 100%; height: 150px;"></iframe>';
// Match the first `<body>` tag
preg_match( '/(?:<body.*>)/U', $buffer, $matches );
// Return our buffer with iframe appended to the body match
return str_replace( $matches[0], $matches[0].$iframe, $buffer );
}
// An early hook with the DOM ready to fire on
add_action( 'template_redirect', function(){
ob_start();
ob_start( 'Danger_insert_iframe' );
});
What this does is matches the
<body [any class/js/data attributes here]>
and will then replace it with
<body [any class/js/data attributes here]><iframe></iframe>
Here's a Working Demo
It's not exactly elegant, but it will get the job done. The first thing that came to mind was a regex match for the body, but you may be better with another manipulation method like DOMDocument. For now though, this will get you started.
Original Answer:
While there's not really a *perfect* way to go about this, I would avoid _hacking_ a solution together. I've seen all sorts of strange things, including hooking in a `</head>` to `wp_head`, and directly inserting content like you've mentioned.
Your best best, and the most "accepted" way to do this, is to use a [Child Theme](https://codex.wordpress.org/Child_Themes). Ultimately, it will use the parent theme like the regular theme, but you can override parts of it with the child theme. This is *mostly* future-proof, unless the parent theme structure *radically* changes.
This gist of these would be to set up a blank Child Theme, and copy the `header.php` (or equivalent file) from the parent theme, and find the opening body tag, usually `<body <?php body_class(); ?>>`
Then, insert your own [`do_action()`](https://developer.wordpress.org/reference/functions/do_action/), so the new file will start with:
<body <?php body_class(); ?>>
<?php do_action('Danger_after_body'); ?>
Then create a `functions.php` file in the Child Theme and use that to deal with content on that hook.
add_action( 'Danger_after_body', 'Danger_insert_content' );
function Danger_insert_content(){
echo 'This Content is always after the <body> tag';
}
If this won't work for you (truthfully, it should except in a few instances), and you are just inserting simple content - you could just target the `body` with JavaScript and insert content that way.
You could also find the first hook that fires in your current theme and add high priority functions to that, but depending on the theme layout that can get messy and falls under the strange hack solutions I mentioned earlier.
This question already has answers here:
How to display raw HTML code on an HTML page
(30 answers)
Closed 3 years ago.
I'd like to add an area to a page where all of the dynamic content is rendered as plain text instead of markup. For example:
<myMagicTag>
<b>Hello</b> World
</myMagicTag>
I want the <b> tag to show up as just text and not as a bold directive. I'd rather not have to write the code to convert every "<" to an "<".
I know that <textarea> will do it, but it has other undesirable side effects like adding scroll bars.
Does myMagicTag exist?
Edit: A jQuery or javascript function that does this would also be ok. Can't do it server-side, unfortunately.
You can do this with the script element (bolded by me):
The script element allows authors to include dynamic script and data blocks in their documents.
Example:
<script type="text/plain">
This content has the media type plain/text, so characters reserved in HTML have no special meaning here: <div> ← this will be displayed.
</script>
(Note that the allowed content of the script element is restricted, e.g. you can’t have </script> as text content (it would close the script element).)
Typically, script elements have display:none by default in browser’s CSS, so you’d need to overwrite that in your CSS, e.g.:
script[type="text/plain"] {display:block;}
You can use a function to escape the < >, eg:
'span.name': function(){
return this.name.replace(/</g, '<').replace(/>/g, '>');
}
Also take a look at <plaintext></plaintext>. I haven't used it myself but it is known to render everything that follows as plain text(by everything i mean to say it ignores the closing tag, so all the following code is rendered as text)
The tag used to be <XMP> but in HTML 4 it was already deprecated. Browser's don't seem to have dropped its support but I would not recommend it for anything beyond quick debugging. The MDN article about <XMP> lists two other tags, <plaintext> and <listing>, that were deprecated even earlier. I'm not aware of any current alternative.
Whatever, the code to encode plain text into HTML is pretty straightforward in most programming languages.
Note: the term similar means exactly that—all three are designed to inject plain text into HTML. I'm not implying that they are synonyms or that they behave identically—they don't.
There is no specific tag except the deprecated <xmp>.
But a script tag is allowed to store unformatted data.
Here is the only solution so far showing dynamic content, as you wanted.
Run code snippet for more info.
<script id="myMagicTag" type="text/plain" style="display:block;">
<b>Hello</b> World
</script>
Use Visible Data-blocks
<script>
document.querySelector("#myMagicTag").innerHTML = "<b>Unformatted</b> dynamic content"
</script>
No, that's not possible, you need to HtmlEncode it.
If your using a server-side language, that's not really difficult though.
In .NET you would do something like this:
string encodedtext = HttpContext.Current.Server.HtmlEncode(plaintext);
In my application, I need to prevent HTML from rendering
"if (a<b || c>100) ..."
and
"cout << ...".
Also the entire C++ code region HTML must pass through the GCC compiler with the desired effect. I've hit on two schemes:
First:
//<xmp>
#include <string>
//</xmp>}
For reasons that escape me, the <xmp> tag is deprecated. I find (2016-01-09) that Chrome and FF, at least, render the tag the way I want. While researching my problem, I saw a remark that <xmp> is required in HTML 5.
Second, in <head> ... </head>, insert:
<style type="text/css">
textarea { border: none; }
</style>
Then in <body> ... </body>, write:
//<br /> <textarea rows="4" disabled cols="80">
#include <stdlib.h>
#include <iostream>
#include <string>
//</textarea> <br />
Note: Set "cols="80" to prevent following text from appearing on the right. Set "rows=..." to one more line than you enclose in the tag. This prevents scroll bars. This second technique has several disadvantages:
The "disabled" attribute shades the region
Incomprehensible, complex comments in the code sent to the compiler
Harder to understand
More typing
However, this methhod is neither obsolete nor deprecated. The gods of HTML will make their faces to shine unto you.