So I have this variable of $date = array($year,$month); inside a couple of nested foreach statements. I have a link that when pressed should pass the $date variable over to my functions.php for me to play around with.
I'm using wordpress and so far I understand the link has to work something like this:
$link = admin_url('admin-ajax.php?[$date variable needs to go here]&post_id='.$post->ID.'&nonce='.$nonce);
Basically my question is how exactly does the link above need to be formatted to send my variable? Also, on the server side, how best to receive that variable?
First of all, you can't send arrays directly through GET requests (GET requests are the ones with the parameters visible in the url, in layman terms)
therefore, you should do the following:
$date = "$year-$month"; //example: 2013-09
$link = admin_url('admin-ajax.php?my_date='.$date.'&post_id='.$post->ID.'&nonce='.$nonce);
breaking the url down to the components, in layman terms:
everything before the ? is the server address and the page that needs to be served
everything after is the so-called "querystring", which is a sequence of pairs (A=B) separated by ampersands &.
so, a URL that looks like this
www.example.com/dynamic_page.php?A=B&C=D&E=F
means:
visit www.example.com, fetch the page named "dynamic_page.php" and use the value B for the variable A, the value D for the variable C and the value F for the variable E.
Related
I'm trying to put a script together for a client that needs to be able to accept a web address in a query string without it first being urlencoded. An example would be like this:
http://foo.com/script.php?url=www.amazon.co.uk/ESET-Smart-Security-User-Year/dp/B005NPFOBM/ref=sr_1_1?s=software&ie=UTF8&qid=1341685530&sr=1-1
However, when I echo out the contents of $_GET['url'] it gives me the following:
www.amazon.co.uk/ESET-Smart-Security-User-Year/dp/B005NPFOBM/ref=sr_1_1?s=software
So basically it seems to choke on the first ampersand - i'm guessing because it thinks that its another variable.
Aside form urlencoding, are there any tricks to getting this working? I could probably POST it from a form, but this defeats the idea of the script.
For this specific use case, you should use $_SERVER['QUERY_STRING'] instead. This will give you the full query string in one go, you can then split it yourself.
In your example, PHP is assuming that the & is the delimiter for the next GET variable.
you could ask the query parameters, and add them to the URL you received. List the remaining parameters in $_GET in the proper order, and add them add the end of $_GET['url'].
$_GET['url']
+ '&ie=' + $_GET['ie']
+ '&qid=' + $_GET['qid']
+ '&sr=' + $_GET['sr']
Be careful that you might get an extra parameter url someday.
http://foo.com/script.php?url=www.amazon.co.uk/ESET-Smart-Security-User-Year/dp/B005NPFOBM/ref=sr_1_1?s=software&ie=UTF8&qid=1341685530&sr=1-1&url=http://someAmazoneStuff
Is it possible to programatically change the query URL within PHP? I know I can use the $_GET['something'] function to get data from a URL query, but I don't know how to change a query string programatically in PHP.
This is an example of what I want to do:
//---- index.php ----\\
$variable = 23;
And my URL is: http://example.com/index.php?variable=23
So if I make $variable = 10 later on in the program (not using headers, and not hard-coded into a link), I want to be able to programatically update the query URL, so that my URL will now read:
http://example.com/index.php?variable=10
Is this even possible, without using forms?
header("Location: index.php?variable=10");
or do you mean
$_GET['variable'] = 10;
?
This might be a basic question and I've been searching for a safe and clean way to do this. Im passing a normal string which CAN include special characters (like $ ^ % etc). How can I do this in the url? For example I have a variable called $text which In addto.php from $_GET. How do I then transfer this to more.php?
'more.php?varname='.urlencode($_GET['text']);
urlencode sounds like what you want.
(from the docs)
This function is convenient when encoding a string to be used in a query part of a URL, as a convenient way to pass variables to the next page.
You can pass data through an URL, it should be in the form of key/value pairs, but you shouldn't use it to pass too much data because an URL has a limit. You also should not pass sensitive information.
A key/value pair is something like this:
key=value
If you have more then one pair, you need to separate them using the & char. Here is an example:
myScript.php?color1=blue&color2=red
The string after ? is called the Query String. With PHP you can easily access those key/value pairs using the super-global $_GET. So, in myScript.php you do:
$a = $_GET['color1'];
$b = $_GET['color2'];
Now, if you are going to create a dynamic query string, you should use urlencode() at least, so any special characters will be translated to maintain a proper URL format.
Please read the following:
http://php.net/urlencode
http://php.net/manual/en/function.http-build-query.php
Im not really sure what im looking for but currently in my system i send a long url like this:
$name=1&option=2&field=4....
And its quite long. So if i have a list of values like:
name
option
field
can i put them into a string in which i can break at certain points eg by a slash or whatever.
And then encode the string so its completely random like, so i only have one field to send:
&data=JKHFGDKGLKJHFKDJHFKJDHFKHDF
Then finally i can decode the other side and break apart.
Is there a pre-built function to do this?
WHAT IT IS:
im sending data to paypal, but i have a few custom variables i wish to send, now for some reason my IPN isnt geting them, not sure why, but if i add one called custom it get to the IPN fine. So i thought if i just send one called custom in a random format and then decode?
You could simply Base64-encode your data.
$a = array('name' => '1', 'option' => '2', 'field' => '4');
$temp = json_encode($a); // convert array to string
$data = base64_encode($temp); // encode string
output:
"eyJuYW1lIjoiMSIsIm9wdGlvbiI6IjIiLCJmaWVsZCI6IjQifQ=="
To send this in an URL, you must encode it once more (like you must encode all data you would send in a URL)
$url = $url . "&data=" . urlencode($data)
The intermediary step through JSON ensures your data will kep its structure and will be easily decodeable on the receiving side.
On the downside: Your URL will be longer.
Use base64_encode and then base64_decode, this will solve your problem.
If you don't know what you are looking for we can't imagine that lol.
Anyway If i got you, you can do this, considering you have built your string:
$string ="$name=1&option=2&field=4";
You could pass it as a single param with:
$data = url_encode($string);
Other than url_encode you can use base64_encode
As the commenter (Bobby) says - consider using POST when you want to send larger sets of data and prevent your URL from becoming unmanageably long or ugly.
GET variables are handy for providing the user with a page they can bookmark directly which is desirable in some cases, such as on a search page with a query string and/or filters already filled in, so that the user can return to a search and check for new results periodically without having to reset all of their choices.
POST variables are better if you don't need that sort of functionality, you don't need to encode/decode them for URLs and they can't be bookmarked directly (which is also desirable in many cases).
To answer your original question though, if you really, really had to send the variable(s) on the URL and you wanted to just send one apparently random string, I suggest writing a couple of encode/decode functions of your own (since I assume the object of the excercise is not to encrypt it against tampering, just to make your URLs friendlier). This will be all the easier if there are restrictions to what the variables can be, and more difficult if they can be absolutely anything.
For example - if you have the following vars and possible settings:
var1 (apple, banana, orange)
var2 (car, motorbike, bicycle)
var3 (red, yellow, green)
Normally, you'd make a URL like:
http://www.mysite.com/page.php?var1=banana&var2=car&var3=green
If you assign the variables to numbers (for example) so that var1, var2 and var3 would be 1, 2 or 3 - then you could send over a URL like:
http://www.mysite.com/page.php?vars=213
Break it down at the other end into single numbers and convert those back into 'banana', 'car', and 'green'.
But seriously.... I'd look at POST first unless there is very specific reason why you would use this sort of approach - i've used it before for shortening a URL to make it more sharable on social media and forums.
I know the title isn't very clear. I'm new to PHP, so there might be name for this kind of thing, I'll try to explain as best as I can. Sometimes in a URL, when using PHP, there will be a question mark, followed by data. I'm sorry, I know this is very noobish, but I'm not sure what it's called to look for a tutorial or anything. Here is what I mean:
http://www.website.com/error_messages.php?error_id=0
How do you configure it to display different text depending on what the number is (in this example it's a number)
Could somebody please tell me what this is called and how I could do this? I've been working with PHP for a couple days and I'm lost. Thank you so very much for understanding that I am very new at this.
That "data" is the URL querystring, and it encodes the GET variables of that HTTP request.
Here's more info on query strings: http://en.wikipedia.org/wiki/Query_string
In PHP you access these with the $_GET "super-global" variable:
// http://www.website.com/error%5Fmessages.php?error%5Fid=0
// %5F is a urlencoded '_' character, which your webserver will most likely
// decode before it gets to PHP.
// So ?error%5Fid=0 reaches PHP as the 'error_id' GET variable
$error_id = $_GET['error_id'];
echo $error_id; // this will be 0
The querystring can encode multiple GET variables by separating them with the & character. For example:
?error_id=0&error_message=Something%20bad%20happened
error_id => "0"
error_message => "Something bad happened"
In that example you can also see that spaces are encoded as %20.
Here's more info on "percent encoding": http://en.wikipedia.org/wiki/Percent-encoding
The data after the question mark is called the "query string". It usually contains data in the following format:
param1=value1¶m2=value2
Ie, it is a list of key-value pairs, each pair separated with the ampersand character (&). In order to pass special characters in the values, they have to be encoded using URL-encoding format: Using the percent sign (%) followed by two hexadecimal characters representing the character code.
In PHP, parameters passed via the query string are automatically propagated to your script using the super-global variable $_GET:
echo $_GET['param1']; // will produce "value1" for the example above.
The raw, unprocessed query string can be retrieved by the QUERY_STRING server variable:
echo $_SERVER['QUERY_STRING'];
It's called the query string.
In PHP you can access its data via the superglobal $_GET
For example:
http://www.example.com/?hello=world
<?php
// Use htmlspecialchars to prevent cross-site scripting attacks (XSS)
echo htmlspecialchars($_GET['hello']);
?>
If you want to create a query string to append to a URL you can use http_build_query():
$str = http_build_query(array('hello' => 'world'));
As previously described, the data after the ? is the querystring (or GET data), and is accessed using the $_GET variable. The $_GET variable is an array containing the name=value pairs in the querystring.
Here is a breif description of $_GET and an example of it's usage:
http://www.w3schools.com/php/php_get.asp
Data can also be submited to a PHP script as POST data (found in the $_POST variable), which is used for passwords, etc, and is not stored in the URL. The $_REQUEST variable contains both POST and GET data. POST and GET data usually originates from being entered into a web form by a user (but GET data can also come directly from a link to an address, like in your example). More info about using web forms in PHP can be found here:
http://www.w3schools.com/php/php_forms.asp
its called "query string"
and you can retrieve it via $_SERVER["QUERY_STRING"]
or you can loop through $_GET
in this case the error_id, you can check it by something like this
echo $_GET['error_id'];
The term you are looking for is GET. So in php you need to access the GET variables in $_GET['variable_name'], e.g. in the example you gave $_GET['error_id'] will contain the value 0. You can then use this in your logic to echo back different information.
The bit after the question mark is called a Query String. The format is typically, although not necessarily always, key-value pairs, where the pairs are separated by an ampersand (&) and the value is separated from the name by an equals sign (=): ?var1=value1&var2=value2&.... Most web programming environments provide an easy way to access name-value pairs in this format. For example, in PHP, there is a superglobal, which is an associative array of these key-value-pairs. In your example, error_id would be accessible via:
$_GET['error_id']
The reason for the name "GET" is that query string variables are typically associated with a HTTP GET request. POST requests can contain GET variables too, whereas GET requests can't contain POST variables.
As to the rest of your question, you could approach the text issue in a number of ways, the simplest being switching on the error id:
$error_id = isset($_GET['error_id']) ? $_GET['error_id'] : 0;
switch($error_id) {
case 1:
echo "Error 1";
break;
default:
echo "Unknown Error";
break;
}
and more complex ways involve looking up the error message from a file, database or what have you.