Per aspera ad astra. AJAX also had a number of obstacles on its way to prominence. No sooner had the issues of non-support and incompatibility been resolv and ajax presentations could start to take off, but there was a problem with addressing the content – it was impossible to create a link to other than the default content, and it was also impossible to get to the previous content using the Back button.
Although the content chang, it was still the same page with the same address! But even these problems were promptly resolv. And that by assigning a so-call anchor to each certain content. Thanks to it, each such content has its own address (e.g.:http://priklad.cz/ajax.html#cast3), which can be referenc and the request content will then be generat according to the part of the address behind the grid. At the same time, this creat the opposite problem – if the Ajax application changes the address content too quickly, it fills the browser’s history with ballast.
However, it was necessary
To deal with uk mobile phone number data other difficulties, the solution of which was already significantly more complicat.
Also read the first part of the series on server-browser communication: Ajax in a nutshell .
Cross-origin requests
The scope of AJAX is limit by the same origin policy. The same origin policy ) – this means that the page must come. The same server from which it draws data. And the port and protocol must also be the same. In most cases, this restriction is not a problem. Sometimes, however, the purpose of the application requires the page to be able to communicate with multiple servers (or multiple services on different domains), which this limitation prevents. Is there any way around it? Yes, the site can communicate with only one server, but it can communicate b2b marketing success depends on understanding buyer behavior with all others. Through this one server, the application can access data sources from other servers. However, there is also a direct solution – it has the abbreviation CORS (Cross-Origin Resource Shar). It is essentially an additional protocol that modifies the current rules of communication between the browser and the server in such a way that data sources outside the home domain are made available to Ajax applications.
Preflight requests of the OPTIONS type, containing the special headers list below, play a key role in this. Using them, the browser bz lists first asks the server if it is willing to provide data to the given application, and bas on the response.