Php api receiving cookie get request. How to send a post request from a browser: post method


Greetings, dear readers of the blog site. In the process of developing various web services, it periodically becomes necessary to collect various information from other sites. Those. required to produce site parsing. The peculiarity of parsing is a quick and automated collection of data and content from the pages of the site. For example, it is often required to obtain a catalog of goods, including pictures, from various online stores in automatic mode. In this case, the site parsing mechanism will come in handy.

Basically, php uses two ways to get content from the pages of the site.

1. get - request using a function file_get_contents().

The function allows you to get the contents of a file as a single line and has the following syntax:

string file_get_contents(string filename [, bool use_include_path [, resource context [, int offset [, int maxlen]]]])
where filename is the path to the file.

On failure, the function returns FALSE.

You can specify a URL as a file name, that is, you can specify the address of the desired web page, then the function will return its content in the form of an html code. For example:

$url = "https://site/";
$result = file_get_contents($url);

2. Using the library CURL.

In the case of using CURL, the code becomes more cumbersome, but there are more different possibilities, since the library has many settings and allows you to perform get and post requests.

Getting page content consists of four steps:

  • session initialization with the curl_init() function;
  • setting the required parameters using the curl_setopt() function;
  • execution of the request by the curl_exec() function;
  • closing the session with the curl_close() function.

For example:


{





}

Using the CURLOPT_URL option, the web page address is specified, the CURLOPT_RETURNTRANSFER option, if the value is non-zero, the result will be returned, not displayed.

If it is needed make a POST request to a remote site, then you need to set the CURLOPT_POST option to true , and put the transmitted data in the CURLOPT_POSTFIELDS option:

if ($curl = curl_init ()) //session initialization
{
curl_setopt ($curl, CURLOPT_URL, "http://website/");//specify page address
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($curl, CURLOPT_POST, true);
curl_setopt($curl, CURLOPT_POSTFIELDS, "i=1");
curl_setopt($curl, CURLOPT_HEADER, 0);
$result = curl_exec($curl);//execute request
curl_close($curl);//close session
}

As a result of both methods, the content of the given page gets into the $result variable in the form of a line of html code. After that, you can proceed directly to parsing the page, that is, to extracting the necessary data from the contents of the string. For example, get all pictures from a page or extract text content.

For parsing, you can use regular expressions, but it's better to use the built-in library DOMDocument or a library SimpleHTMLDOM.

That's all, see you soon!

Yes, everyone has learned something at some point. The only thing that distinguishes people in this regard is that for some, the teachings are given easily, while others cannot understand the essence of the issue for many months. Today we will talk about POST and GET requests in HTML\PHP.

The POST and GET requests themselves (hereinafter referred to as requests) have long been rooted in all Internet resources. If suddenly someday an alternative to these technologies appears, then probably it will not be soon, and probably not necessary. Because our requests quite fully fulfill the task of exchanging data between Internet pages.

Let's look at a GET request first. Let's create an index.php file with a standard html code, and place a form on it, let it be a product order form.

Let's take a look at the tag here. form. It has two parameters action and method. The first is responsible for the address of the page to which we will transfer our data, the second is for the method by which this data will be transferred. Inside this tag, we describe the set of our data that we want to transfer. Names must be assigned to data (parameter name). It is also required input type submit, which is the button that sends the data when clicked.

Let's save our file and open it in a browser.
The path of our page in the browser is ".../index.php". On the page itself, we see two input fields and a button. Let's fill in something in our fields and click on the "Order" button. Our page has been updated. Let's look at her address: ".../index.php?orderName=Test&count=12". (I typed in the first field the word 'Test' in the second '12'). As we can see, the page address has changed a bit. The fact is that the transmission of GET parameters by a request is carried out by assigning them to the page address string. Parameters are separated from the main address by the '?' character, and different parameters by the '&' character. The parameter structure is as follows: parameter_name=value. The name of the parameter will match the value of the name attribute in the input field.
Let's edit the page code a bit:

> >

Now click on the "Order" button again. As we can see, the page has been updated, but our fields remained filled. This is due to the fact that we provided a default value for our fields. Moreover, these values ​​are the received GET parameter. As we can see in the PHP code, GET parameters are an array with a string index equal to the parameter name. If we now play around with the site address and change the parameter values ​​\u200b\u200bin it and press the “Enter” button, then we will again notice a picture with updating the page and filling out our form.

Obviously, sending secret or service data in a GET request is wrong (and not safe). It is better to use it to transfer, for example, the id of the news that should be taken from the database or the name of the page that should be displayed.

POST request is another matter. It works similarly, but does not store the parameters in the address bar. Let's change our shape:

$_POST["orderName"]?> > $_POST["count"]?> >

As you can see, not much has changed, however! Let's open our page, fill in something in the fields and press the "Order" button. Everything worked in the same way, however (however), as we see in the query string, the address “…/index.php” flaunts without any kind of parameters. Thus, we kind of "hid" our data from prying eyes. Of course, the concept was hidden, rather conditional, since this data can still be intercepted, but that's another story. Let's add the parameters ".../index.php?orderName=Trololo&count=100" to our address and press "Enter". As we can see, the page has loaded, but even despite the passing of parameters, the fields turned out to be empty. This suggests that despite the great similarity, these types of requests do not intersect with each other in any way, and if there is a need, it is worth writing a handler for each type of request separately.

I think that's enough. The basics of the question, I think, are described with a head.

And a bit more… Don't forget to check the passed parameters. If you know for sure that the parameter must be a number, then cut all attempts to pass a non-numeric value, etc ...

The GET and POST methods in HTTP and HTTPS are the two most popular methods used to transfer data from a client to a server using the HTTP (Hypertext Transfer Protocol) protocol. Both GET and POST can be used to send a request and receive a response, but there is a significant difference between the two.

The difference between GET and POST requests in HTTP or HTTPS is a popular question in every web programming interview. Since HTML does not depend on web server technology such as Java, ASP or PHP and HTTP is the main protocol in the Internet space, the importance of understanding the GET and POST methods cannot be clearly ignored. In this article, we will look at what is the HTTP GET method, what is the HTTP POST method, when to use one or the other request, and what is the difference between them. Let's analyze each concept separately.

What is HTML?

HTML is the language used to create web pages. Hypertext refers to the hyperlinks that an HTML page can contain. A markup language refers to the way tags are used to define the layout of a page and elements on a page.
The following is an example of HTML that is used to define a basic web page with a title and one paragraph of text:



<Голова>
<Название>TechTerms.com

<Тело>

This is an example of a paragraph in HTML.

The first line specifies the type of content contained in the document., and , which are all included in the example above. The page title, metadata, and links to files with anchors are placed between the actual content of the page is between the tags .

The web has gone through many changes over the past few decades, but HTML has always been the primary language used to develop web pages. Interestingly, although websites have become more advanced and interactive, HTML has become simpler. If you compare the source of an HTML5 page with a similar page written in HTML 4.01 or XHTML 1.0, the HTML5 page will have less code. This is because modern HTML relies on Cascading Style Sheets or JavaScript to format almost every element within a page.

Many dynamic websites generate web pages on the fly using a server-side scripting language such as PHP or ASP. However, even dynamic pages must be formatted using HTML. Therefore, scripting languages ​​often generate HTML code that is sent to a web browser.

The HTTP Hypertext Transfer Protocol is designed for communication between clients and servers and operates as a request-response protocol.

The web browser can be the client, and the application on the computer hosting the website can be the server.

The client (browser) sends an HTTP request to the server, the server returns a response that contains information about the state of the request and may also contain the requested content.

Two request methods GET and POST

Two commonly used methods for request-response between client and server:

    GET - requests data from the specified resource;

    POST - sends data to be processed to the specified resource.

The translation of GET and POST literally means receiving and post-processing.

Learn more about HTTP

HTTP is the protocol used to transfer data over the Internet. It is part of the Internet Protocol package and defines the commands and services used to transfer web page data.

HTTP uses the server-client model. The client can be a home computer, laptop, or mobile device. An HTTP server is typically a web host with web server software such as Apache or IIS. When a user accesses a website, the browser sends a request to the appropriate web server and responds with an HTTP status code. If the URL is valid and the connection is granted, the server will send the web page and associated files to the browser.

Common HTTP status codes include:

    200 - successful request (web page exists);

    301 - Moves permanently (often redirects to a new URL)

    401 - unauthorized request (authorization required);

    500 is an internal server error (often caused by server misconfiguration).

POST and GET in HTTP

HTTP defines the GET and POST commands that are used to process form submissions on websites. The CONNECT command is used to facilitate a secure connection that is encrypted using SSL. Encrypted HTTP connections occur over HTTPS, an extension of HTTP designed for secure data transfers.

URLs beginning with "http://" are accessible via standard hypertext transfer protocols and use port 80 by default. URLs beginning with "https://" are accessible over a secure HTTPS connection and often use port 443.

POST

POST is a series of system checks performed by computers and other electronic devices when they are turned on. Test results can be displayed on the screen, output via flashing LEDs, or simply recorded internally. On computer systems, the POST operation is performed at the beginning of the boot sequence. If all tests pass, the rest of the startup process will continue automatically.

Mac and Windows device operating systems run POST each time the computer boots or restarts. The scan checks the hardware and ensures that the processor, RAM, and storage devices are working properly. If an error occurs during POST, the startup process may pause or stop completely, and a message may appear on the monitor. On a PC, POST errors are often displayed on the BIOS information screen. They can be output as crypt codes such as "08" or as a system message such as "System memory error at offset". On a Mac, POST errors are often indicated by simple graphics, such as a broken folder icon, which indicates that no boot device was found.

physical manifestations

In some cases, the computer screen may not even turn on before POST errors. If this happens, error codes may be displayed through flashing LEDs or beeps. For example, an Apple iMac will play three consecutive tones, pause for five seconds, and then repeat the tones when bad RAM is detected during startup. Most PCs also beep when they encounter POST errors, although each manufacturer uses their own codes.

POST is a rather technical term that only computer technicians use on a regular basis. However, it is a good acronym as it helps to better understand error messages that may appear on computers or other electronic devices. If the computer does not start due to a POST error, you can use another device to look up the meaning and cause of the error from the manufacturer's website. You can then take the appropriate action, such as removing the memory module or reinstalling the graphics card and then restarting the hardware.

GET

POST is also a method of passing HTML form variables from one web page to another without displaying them in the address bar. An alternative method is GET, which adds values ​​to the URL. HTTP POST requests provide additional data from the client (browser) to the server in the message body. In contrast, GET requests include all the required data in the URL. Forms in HTML can use any method by specifying method=POST or method=GET (default) on the element

. The specified method determines how form data is submitted to the server. When the GET method is used, all form data is URL-encoded as query string parameters. With POST, the form data appears in the message body of the HTTP request.

Differences in form presentation

The POST request method asks the web server to accept and store the data enclosed in the body of the request message. Often used when uploading a file or submitting a completed web form.

The HTTP GET request method retrieves information from the server. As part of a GET request, some data may be passed in the URL query string, specifying search terms, date ranges, or other information that defines the request.

As part of a POST request, an arbitrary amount of data of any type can be sent to the server in the body of the request message. The header field in a POST request typically specifies the internet media type of the message body.

The main difference between GET and POST requests is that they correspond to different HTTP requests as defined in the HTTP specifications. The submission process for both methods starts in the same way: the form dataset is created by the browser and then encoded in the manner specified by the enctype attribute. For METHOD="POST the enctype attribute can be multipart/form-data or application/x-www-form-urlencoded, whereas for METHOD="GET" it is only triggered via application/x-www-form-urlencoded. This set form data then passed to the server.

To submit a form with METHOD = "GET", the browser constructs a URL by taking the value of the action attribute and appending to it a set of form data encoded using the application/x-www-form-urlencoded content type). The browser then treats this URL as if it were referring to a link (or as if the user had manually typed in the URL). The browser splits the URL into parts and recognizes the host, then sends a GET request to that host with the rest of the URL as an argument. It is important to note that this process means that the form data is limited to ASCII codes. Special care should be taken to encode and decode other types of characters when passing them to an ASCII URL.

A form submission with METHOD="POST" causes a POST request to be sent using the value of the action attribute and a post generated according to the content type specified by the enctype attribute.

PHP

PHP is embedded in HTML. This means that PHP code can be inserted into an HTML page. The PHP code is read or parsed by the server that hosts the page. The output of PHP's GET and POST functions on a page is usually returned as HTML code that can be read by the browser. Because the PHP code is converted to HTML before the page is loaded, users cannot view the PHP code on the page. This makes PHP pages sufficient for accessing databases and other protected information.

Much of PHP's syntax is borrowed from other languages ​​such as C, Java, and Perl. However, PHP has a number of unique features and special features. The purpose of this language is to enable web developers to quickly and easily write dynamically generated pages.

Wordpress

WordPress is a free content management system used to create and maintain websites. Its ease of use and unique blogging features have helped it become the most popular blogging tool on the web.

The WordPress interface allows anyone with no web development experience to create and publish a website. Built-in blogging tools provide an easy way to track individual posts, visitors, and user comments.

Although there are thousands of WordPress templates and plugins available, the POST GET system in WordPress still has its limitations. Since this is a template-based service, the user must start with a pre-built website rather than creating pages from scratch. Also, there is no way to embed scripts or maintain a database with the same level of control that a custom website offers.

The POST_GET_ID() tool allows scripting to manipulate the element as it has a unique id and when submitting it as a form via these methods the dropdown will be sent with a unique id which allows the script to notice which post is running. Alternatively, a hidden variable can be sent, which will allow the script to see which post belongs to the view.

This post is an answer to a question asked in a comment to one of my articles.

In this article, I want to tell you what the GET/POST/PUT/DELETE and other HTTP methods are, what they were invented for and how to use them in accordance with REST.

HTTP

So, what is one of the main protocols of the Internet? I will send pedants to RFC2616, and I will tell the rest in a human way :)

This protocol describes the interaction between two computers (client and server), built on the basis of messages called request (Request) and response (Response). Each message consists of three parts: start line, headers and body. In this case, only the start line is required.

The start lines for the request and the response have a different format - we are only interested in the start line of the request, which looks like this:

METHOD URI http/ VERSION ,

Where METHOD is just the HTTP request method, URI is the resource identifier, VERSION is the protocol version (version 1.1 is currently relevant).

Headers are a set of name-value pairs separated by a colon. Various service information is transmitted in the headers: the message encoding, the name and version of the browser, the address from which the client came (Referrer), and so on.

The body of the message is actually the transmitted data. In the response, the transmitted data, as a rule, is the html page requested by the browser, and in the request, for example, in the body of the message, the contents of the files uploaded to the server are transmitted. But as a rule, there is no message body in the request at all.

HTTP interaction example

Consider an example.

Inquiry:
GET /index.php HTTP/1.1 Host: example.com User-Agent: Mozilla/5.0 (X11; U; Linux i686; ru; rv:1.9b5) Gecko/2008050509 Firefox/3.0b5 Accept: text/html Connection: close
The first line is the query string, the rest are headers; message body missing

Answer:
HTTP/1.0 200 OK Server: nginx/0.6.31 Content-Language: ru Content-Type: text/html; charset=utf-8 Content-Length: 1234 Connection: close ... THE HTML PAGE ITSELF...

Resources and Methods

Let's return to the starting query string and remember that it contains such a parameter as a URI. This stands for Uniform Resource Identifier - a uniform resource identifier. A resource is, as a rule, a file on the server (an example URI in this case is "/styles.css"), but in general, any abstract object can also be a resource ("/blogs/webdev/" - points to the "Web development", and not on a specific file).

The HTTP request type (also called the HTTP method) tells the server what action we want to perform on the resource. Initially (in the early 90s) it was assumed that the client could only want one thing from a resource - to receive it, but now you can create posts, edit a profile, delete messages and much more using the HTTP protocol. And it is difficult to combine these actions with the term "receiving".

To differentiate actions with resources at the level of HTTP methods, the following options were invented:

  • GET - getting a resource
  • POST - resource creation
  • PUT - resource update
  • DELETE - deleting a resource
Pay attention to the fact that the HTTP specification does not oblige the server to understand all methods (which are actually much more than 4) - only GET is required, and also does not indicate to the server what it should do when receiving a request with a particular method. This means that the server, in response to a DELETE /index.php HTTP/1.1 request is not obliged to delete the index.php page on the server, the same as for a GET /index.php HTTP/1.1 request is not obliged to return you the index.php page, he can delete it, for example :)

REST comes into play

REST (REpresentational State Transfer) - this term was introduced in 2000 by Roy Fielding - one of the developers of the HTTP protocol - as the name of a group of principles for building web applications. In general, REST covers a wider area than HTTP - it can be used in other networks with other protocols. REST describes the principles of interaction between the client and the server, based on the concepts of "resource" and "verb" (you can understand them as a subject and a predicate). In the case of HTTP, the resource is defined by its URI, and the verb is the HTTP method.

REST proposes to stop using the same URI for different resources (that is, the addresses of two different articles like /index.php?article_id=10 and /index.php?article_id=20 - this is not a REST way) and use different HTTP methods for different actions. That is, a web application written using the REST approach will delete a resource when it is accessed with the HTTP DELETE method (of course, this does not mean that it is necessary to give the opportunity to delete everything and everyone, but any the application's delete request must use the DELETE HTTP method).

REST gives programmers the ability to write standardized and slightly prettier web applications than ever before. Using REST, the URI for adding a new user will not be /user.php?action=create (GET/POST method), but simply /user.php (strictly POST method).

As a result, by combining the existing HTTP specification and the REST approach, various HTTP methods finally make sense. GET - returns a resource, POST - creates a new one, PUT - updates an existing one, DELETE - deletes it.

Problems?

Yes, there is a small problem with the application of REST in practice. This problem is called HTML.

PUT / DELETE requests can be sent via XMLHttpRequest, by manually contacting the server (say, via curl or even via telnet), but you cannot make an HTML form that sends a full-fledged PUT / DELETE request.

The fact is, the HTML specification does not allow you to create forms that send data other than via GET or POST. Therefore, for normal operation with other methods, it is necessary to imitate them artificially. For example, in Rack (the mechanism on the basis of which Ruby interacts with a web server; Rails, Merb and other Ruby frameworks are made using Rack), you can add a hidden field called "_method" to the form, and specify the name of the method as the value (for example, "PUT") - in this case, a POST request will be sent, but Rack will be able to pretend that it received a PUT, not a POST.

In PHP scripts, it is very often used to access other sites by making an HTTP request. I know of several ways to implement such requests.

The description of the methods used is superficial - you can get more complete information by clicking on the links in the article.

1. The simplest, but not functional.

As a file, in the file_get_contents() function, you can use the URL of the page.

The function is mainly used for files, but it can also be used for downloading web pages.

Implementation example:

$content = file_get_contents("http://ya.ru"); echo $content;

The disadvantage of this method is that the request occurs only through the GET method and there is no way to specify a timeout.

2. A more complex but functional way.

For this, sockets are used, which can be used not only for HTTP requests. Any request can be implemented on sockets, but knowledge of the HTTP protocol is required and the method itself is rather complicated to understand.

Implementation example:

$socket= fsockopen("www.yandex.ru", 80, $errno, $errstr, 30); if (!$socket) (echo "$errstr ($errno)";) else ( fputs ($socket, "GET / HTTP/1.0\r\nHost: www.yandex.ru\r\n\r\n" ); while (!feof($socket)) (echo fgets ($socket,128);) fclose ($socket);)

The advantage of this method is that you can specify a timeout, a request method, and have full control over all sent data - headers, POST data, etc.

3. Simple and functional way.

Using cURL , it is very easy to make requests and it is possible to set arbitrary parameters - such as timeout, etc.

Implementation example:

$ch = curl_init(); curl_setopt($ch, CURLOPT_URL, "http://ya.ru"); curl_setopt($ch, CURLOPT_HEADER, 0); curl_setopt($ch, CURLOPT_TIMEOUT, 60); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $content= curl_exec($ch); curl_close($ch); echo $content;

The method is the simplest, but requires the cURL library - usually it is already preinstalled on the web server.

In my scripts, I use cURL "wrapped" in a function with already preset parameters.

# setcurlcookie function setcurlcookie($setcookie) ( global $cookie; if (!empty($setcookie)) ($cookie = $setcookie;)) # curl function curl($url, $post = "", $binary = 0) ( global $cookie; $ch = curl_init(); curl_setopt($ch, CURLOPT_URL, $url); if ($binary == 0) ( curl_setopt($ch, CURLOPT_HEADER, 1);) else ( curl_setopt($ch, CURLOPT_HEADER, 0);) curl_setopt($ch, CURLOPT_POST, 1); curl_setopt($ch, CURLOPT_NOBODY, 0); curl_setopt($ch, CURLOPT_POSTFIELDS, $post); curl_setopt($ch, CURLOPT_COOKIE, $cookie); curl_setopt( $ch, CURLOPT_BINARYTRANSFER, $binary); curl_setopt($ch, CURLOPT_TIMEOUT, 60); curl_setopt($ch, CURLOPT_FOLLOWLOCATION, 0); curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1); $result = curl_exec($ch); curl_close( $ch); return $result;)

The first setcurlcookie() function is responsible for storing cookies in a global variable.
Thanks to her, with each next request, cookies will automatically be substituted from the previous request.

The second curl() function can make both GET requests and POST requests. It is also possible to specify the type of data to be received - content with or without a title.

Examples:

GET request:

$content = curl("http://ya.ru/?search=test"); echo $content;

POST request:

$content = curl("http://ya.ru","username=alex&password=qwerty"); echo $content;

$content = curl("http://ya.ru/logo.png","",1); echo $content;

Note: The information in the article is not exhaustive - there may be other ways.


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