What Javascript Cannot Do

What Javascript Cannot Do While there are a large number of things that JavaScript can be utilized to upgrade your pages and improve your guests involvement in your site, there are likewise a couple of things that JavaScript cannot do. A portion of these impediments are because of the way that the content is running in the program window and accordingly can't get to the server while others are because of security that is set up to prevent website pages from having the option to alter your PC. Its absolutely impossible to work around these impediments and any individual who professes to have the option to play out any of the accompanying errands utilizing JavaScript has not considered the entirety of the parts of whatever it is that they are attempting to do. It Cannot Write to Files on the Server Without the Help of a Server-Side Script Utilizing Ajax, JavaScript can send a solicitation to the server. This solicitation can peruse a record in XML or plain content arrangement however it can't keep in touch with a document except if the record approached the server really runs as a content to do the record compose for you. JavaScript can't get to databases except if you use Ajax and have a server-side content to play out the database gets to for you. It Cannot Read From or Write to Files in the Client Despite the fact that JavaScript is running on the customer PC (the one where the site page is being seen) it isn't permitted to get to anything outside of the site page itself. This is accomplished for reasons of security since in any case a page would have the option to refresh your PC to introduce who recognizes what. The main exemption to this are documents called treats which are little content records that JavaScript can write to and read from. The program confines access to treats with the goal that a given website page can just access treats made by a similar webpage. JavaScript can't close a window in the event that it didnt open it. Again this is for security reasons. It Cannot Access Web Pages Hosted on Another Domain Despite the fact that site pages from various spaces can be shown simultaneously, either in independent program windows or in discrete edges inside a similar program window, the JavaScript running on a site page having a place with one area can't get to any data about a page from an alternate space. This assists with guaranteeing that private data about you that might be known to the proprietors of one area isn't imparted to different areas whose site pages you may have open simultaneously. The best way to get to documents from another area is to do an Ajax call to your server and have a server side content access the other space. It Cannot Protect Your Page Source or Images Any pictures on your site page are downloaded independently to the PC showing the site page so the individual review the page as of now has a duplicate of the entirety of the pictures when they see the page. The equivalent is valid for the genuine HTML wellspring of the website page. The website page should have the option to unscramble any site page that is encoded so as to have the option to show it. While an encoded website page may require JavaScript to be empowered all together for the page to have the option to be unscrambled with the goal for it to have the option to be shown by the internet browser, when the page has been decoded any individual who realizes in what manner can without much of a stretch spare the unscrambled duplicate of the page source.