I am working with an XML feed that has, as one of it's nodes, a URL string similar to the following:
http://aflite.co.uk/track/?aid=13414&mid=32532&dl=http://www.google.com/&aref=chris
I understand that ampersands cause a lot of problems in XML and should be escaped by using & instead of a naked &. I therefore changed the php to read as follows:
<node><?php echo ('http://aflite.co.uk/track/?aid=13414&mid=32532&dl=http://www.google.com/&aref=chris'); ?></node>
However when this generates the XML feed, the string appears with the full &
and so the actual URL does not work. Apologies if this is a very basic misunderstanding but some guidance would be great.
I've also tried using %26 instead of & but still getting the same problem.
If you are inserting something into XML/HTML you should always use the htmlspecialchars function. this will escape your strings into correct XML syntax.
but you are running into a second problem.
your have added a second url to the first one.
this need also escaped into url syntax.
for this you need to use urlencode.
<node><?php echo htmlspecialchars('http://aflite.co.uk/track/?aid=13414&mid=32532&aref=chris&dl='.urlencode('http://www.google.com/')); ?></node>
& is correct for escaping ampersands in an XML document. The example you've given should work.
You state that it doesn't work, but you haven't stated what application you're using, or in what way it doesn't work. What exactly happens when you click the link? Do the & strings end up in the browser's URL field? If that's the case, it sounds like a fault with the software you've viewing the XML with. Have you tried looking at the XML in another application to see if the problem is consistent?
To answer the final part of your question: %26 would definitely not work for you -- this would be what you'd use if your URL parameters needed to contain ampersands. Say for example in aref=chris, if the name chris were to an ampersand (lets say the username was chris&bob), then that ampersand would need to be escaped using %26 so that the URL parser didn't see it as starting a new URL parameter.
Hope that helps.
Related
I'm using a 3rd party API that seems to return its data with the entity codes already in there. Such as The Lion’s Pride.
If I print the string as-is from the API it renders just fine in the browser (in the example above it would put in an apostrophe). However, I can't trust that the API will always use the entities in the future so I want to use something like htmlentities or htmlspecialchars myself before I print it. The problem with this is that it will encode the ampersand in the entity code again and the end result will be The Lion’s Pride in the HTML source which doesn't render anything user friendly.
How can I use htmlentities or htmlspecialchars only if it hasn't already been used on the string? Is there a built-in way to detect if entities are already present in the string?
No one seems to be answering your actual question, so I will
How can I use htmlentities or htmlspecialchars only if it hasn't already been used on the string? Is there a built-in way to detect if entities are already present in the string?
It's impossible. What if I'm making an educational post about HTML entities and I want to actually print this on the screen:
The Lion’s Pride
... it would need to be encoded as...
The Lion&;#8217;s Pride
But what if that was the actual string we wanted to print on the string ? ... and so on.
Bottom line is, you have to know what you've been given and work from there – which is where the advice from the other answers comes in – which is still just a workaround.
What if they give you double-encoded strings? What if they start wrapping the html-encoded strings in XML? And then wrap that in JSON? ... And then the JSON is converted to binary strings? the possibilities are endless.
It's not impossible for the API you depend on to suddenly switch the output type, but it's also a pretty big violation of the original contract with your users. To some extent, you have to put some trust in the API to do what it says it's going to do. Unit/Integration tests make up the rest of the trust.
And because you could never write a program that works for any possible change they could make, it's senseless to try to anticipate any change at all.
Decode the string, then re-encode the entities. (Using html_entity_decode())
$string = htmlspecialchars(html_entity_decode($string));
https://eval.in/662095
There is NO WAY to do what you ask for!
You must know what kind of data is the service giving back.
Anything else would be guessing.
Example:
what if the service is giving back & but is not escaping ?
you would guess it IS escaping so you would wrongly interpret as & while the correct value is &
I think the best solution, is first to decode all html entities/special chars from the original string, and then html encode the string again.
That way you will end up with a correctly encoded string, no matter if the original string was encoded or not.
You also have the option of using htmlspecialchars_decode();
$string = htmlspecialchars_decode($string);
It's already in htmlentities:
php > echo htmlentities('Hi&mom', ENT_HTML5, ini_get('default_charset'), false);
Hi&mom
php > echo htmlentities('Hi&mom', ENT_HTML5, ini_get('default_charset'), true);
Hi&;mom
Just use the [optional]4th argument to NOT double-encode.
I ran into a quirky syntax issue.
I am using php and cUrl to pull in data from a web page. The link has several variables. One of them is '<V', but the resulting link keeps translating '<V' as '<V', looking as '<' and the 'less than' symbol, when I need the literal text.
I have looked all over the place to figure out how to force php to read '<V' literally but have not found it.
Any ideas here would be appreciated.
Thanks.
You need to encode your HTML entities. Either use htmlentities or manually type out the string "<V".
I wrote a script that when you enter a textbox, it will open an invisible iframe to a .php file with $_GET of what they wrote into the textbox.
However, for example, if I type: '<3' in it, this is what happens.
PHP determins that the $_GET[s] is blank! Users cant put a simple <3 symbol without getting that error.
Another problem is quotes, if I write any quotes, it will end the entire SRC property.
What should I do? Should I do something with javascript, or even PHP? Please let me know!
Thanks!
Use urlencode to encode the inputted string into a valid one for URL use.
Also be very cautious when allowing user input into your PHP script through the URL. Make sure you do proper checks/sanitization, especially if database operations are involved.
It looks like your iframe is generated by JavaScript, so all those answers that include PHP functions are useless. The data isn't even reaching PHP, so how can any PHP function hope to help?
Instead, try using urlencode from PHPJS, since none of JS's functions really handle all cases well, and this makes it easy for you to use PHP's urldecode to retrieve the data.
You need to encode that character as <.
Regarding double quotes, you can use this trick.
attr='Your string can "contain double quotes"'
or
attr="Your string can 'contain double quotes'"
but while specifying variable=values in url, you don't need to user double quotes, you can directly assign the values.
like
url="test.php?var1=123&var2=345"
rest about sending the <3 characters, you can check for url encoding in javascript & PHP whichever applicable!
I'm using more than one ampersand in my url, see my link below
http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many
When i try to validate in w3c validator it showed hundreds of error because of this & (ampersand).
After that i read some post in here and i got the solution too.
Instead of using (&) If i use (&) w3c validates fine.
But the problem now is in search Engine. Instead of taking (&). it is taking like the below link
http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many
if you copy paste the above link in the address bar it will take you to the wrong page!. Please help how can i solve it.
There must be an error in your code but since we cannot see any of it I think the most important bit is to understand why the W3C validator complaints about raw &.
The HTML syntax contains two basic elements: tags (e.g. <strong>) and entities (e.g. €). Everything else is displayed as-is.
Browsers are expected to ignore errors.
When you type unknown or invalid tags, the browser will do its best to guess and fix it (you are probably aware of that already):
<p>Hello <i>world</b>!</p>
... will render as:
<p>Hello <i>world</i>!</p>
But the same happens when you type an unknown or invalid entity. In your example, there are two invalid entities:
http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many
^^^^ ^^^^^
However, it works because the browser is clever enough to figure out the real URL. Only the validator complaints because it is a tool specifically designed to find errors.
Now, imagine I want to use HTML to write an HTML tutorial and I want to explain the <strong> tag. If I just type <strong>example</strong>, the browser will display example. I need to encode the < symbol so it no longer has a special meaning:
<strong>example</strong>
Now the browser displays <strong>example</strong>, which is precisely the content I want to show.
The same happens with your URL. Since & is part of the entity syntax, when I want to insert a literal & I need to encode it as well:
Barnes & Noble
... will render as Barnes & Noble. Please note that this is only a syntactic trick to insert plain text into a HTML document. Your document shows Barnes & Noble. to all effects, no matter how you encode it. So when you replace & with & in your URL, you are not changing your URL, you are just encoding it.
If search engines are spidering the wrong URL, that means you have actually changed your URL rather than just encoding it, so the source code is:
http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many
... and renders as:
http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many
This can happen, for instance, if you encode twice:
<?php
$url = 'http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many';
$url = htmlspecialchars($url);
$url = htmlspecialchars($url);
echo $url;
... or:
<?php
$url = 'http://www.theonlytutorials.com/video.php?cat=55&vid=3975&auth=many';
$url = htmlspecialchars($url); // Oops: URL is already encoded!
echo $url;
Seems that you made a typo error, it must be & not &amp;
I am having a problem passing a json string back to a php script to process.
I have a json string that's been created by using dojo.toJson() that contains a / and looks like this:
[{"id":"2","company":"My Company / Corporation","jobrole":"Consultant","jobtitle":"System Integration Engineer"}]
When I pass the string back to the php script it get's chopped at the / and creates a malformed json string, which then means I can't convert it into a php array.
What is the best way of escaping the / in this string? I was looking at regular expressions and doing a string.replace() however my regex isn't that strong, and I'm not sure if there are better ways of doing this?
Many thanks
You shouldn't need to do anything special to represent a / in JSON - a string can contain any character except a " or (when not used to start an escape sequence) \.
The problem is possibly therefore in:
the way you parse the JSON server side
the way your parse the HTTP data to get the JSON string
the way you encode the string before making the HTTP request
(I'd bet on it being the last of those options).
I would start by using a tool such as LiveHttpHeaders or Charles Proxy to see exactly what data is sent to the server.
(I'd also expand the question with the code you use to make the request, and the code you use to parse it at the other end).
\/. Take a look here. The documentation is really easy to read, concise and clear. But unescaped / should still be valid in JSON's string so maybe your bug is somewhere else?
Ok. Anyway.
When passing variables to PHP don't use JSON - it's good for passing variables other way.
Instead you better use http://api.dojotoolkit.org/jsdoc/1.3/dojo.objectToQuery method and on PHP side parse standard PHP $_GET variables.
EDIT: Ok, I'm 'lost in the woods' here also, but here's a tip - check if you don't have some mod_rewrite rules in action here. Kind of seems like that.
Also, if you can send me the URL which gave you 404 (you can cut out domain part, i'm interested in script filename and all afterwards) maybe I can give you more detailed answer.
To be clear, whether you choose to send JSON to PHP or use regular form values is a matter of preference. It /should/ work either way. It sounds like you aren't url-encoding the JSON at the client-side so the server-side is treating / as a path delimiter. In which case its borked before json_decode gets to it.
so, try encodeURIComponent( dojo.toJson(stuff) )
json_encode() used to escape forward slashes. like this:
prompt> json_encode(json_decode('"A/B"'));
string(6) ""A\/B""
JSON_UNESCAPED_SLASHES was added in PHP5.4 to suppress this behavior.