ajax - 如果浏览操作，则在Grails中重定向用户

Question

我有一个用于Ajax的Grails Controller Action ，尽管您仍然可以在浏览器中导航和查看页面。

class QuoteController {

def quoteService

/**
 * This page uses the ajaxRandom function defined below to display random quotes.
 */
def random = {
    def randomQuote = quoteService.getRandomQuote()
    [quote:randomQuote]
}

/**
 * I do not want this to be a valid page, but maintain its use as a simple Ajax method.
 */
def ajaxRandom = {
    def randomQuote = quoteService.getRandomQuote()
    response.outputStream << "<q>${randomQuote.content}</q><p>${randomQuote.author}</p>"
}
}

如果有人通过浏览器访问URL，同时又从页面内部维护该方法的Ajax功能，是否可以重定向？

Answer 1

def ajaxRandom = {
    if(!request.xhr) { // this calls the dynamic method request.isXhr()
        redirect action: 'random'
    } else {
        def randomQuote = quoteService.getRandomQuote()
        response.outputStream << "<q>${randomQuote.content}</q><p>${randomQuote.author}</p>"
    }
}

之所以可行，是因为大多数Ajax JS库都将 X-Requested-With header 添加到请求中。 Grails将此 isXhr()方法动态添加到HttpServletRequest类。

// test whether the current request is an XHR request
HttpServletRequest.metaClass.isXhr = {->
     'XMLHttpRequest' == delegate.getHeader('X-Requested-With')                
}