简单的ajax表单使用javascript没有jQuery

Question

我正在使用一个表单,我无法更改标记并且无法使用jQuery.目前,表单将结果发布到新窗口.是否可以将其更改为ajax表单,以便在不改变任何标记的情况下显示提交结果？将结果(标记)从结果页面拉回到表单页面.

这是表格的加价.

<form class="form-poll" id="poll-1225962377536" action="/cs/Satellite" target="_blank">
<div class="form-item">
    <fieldset class="form-radio-group">
        <legend><span class="legend-text">What mobile phone is the best?</span></legend>
                <div class="form-radio-item">
                    <input type="radio" class="radio" value="1225962377541" name="option" id="form-item-1225962377541">
                    <label class="radio" for="form-item-1225962377541">
                        <span class="label-text">iPhone</span>
                    </label>
                </div><!-- // .form-radio-item -->
                <div class="form-radio-item">
                    <input type="radio" class="radio" value="1225962377542" name="option" id="form-item-1225962377542">
                    <label class="radio" for="form-item-1225962377542">
                        <span class="label-text">Android</span>
                    </label>
                </div><!-- // .form-radio-item -->
                <div class="form-radio-item">
                    <input type="radio" class="radio" value="1225962377543" name="option" id="form-item-1225962377543">
                    <label class="radio" for="form-item-1225962377543">
                        <span class="label-text">Symbian</span>
                    </label>
                </div><!-- // .form-radio-item -->
                <div class="form-radio-item">
                    <input type="radio" class="radio" value="1225962377544" name="option" id="form-item-1225962377544">
                    <label class="radio" for="form-item-1225962377544">
                        <span class="label-text">Other</span>
                    </label>
                </div><!-- // .form-radio-item -->
    </fieldset>
</div><!-- // .form-item -->
<div class="form-item form-item-submit">
    <button class="button-submit" type="submit"><span>Vote now</span></button>
</div><!-- // .form-item -->
<input type="hidden" name="c" value="News_Poll">
<input type="hidden" class="pollId" name="cid" value="1225962377536">
<input type="hidden" name="pagename" value="Foundation/News_Poll/saveResult">
<input type="hidden" name="site" value="themouth">

非常感谢任何提示/教程.:)

Answer 1

以下是另一个答案的更优雅的解决方案,更适合现代浏览器.

我的理由是,如果你需要支持旧的浏览器,你很可能使用像jQuery这样的库,从而使这个问题毫无意义.

/**
 * Takes a form node and sends it over AJAX.
 * @param {HTMLFormElement} form - Form node to send
 * @param {function} callback - Function to handle onload. 
 *                              this variable will be bound correctly.
 */

function ajaxPost (form, callback) {
    var url = form.action,
        xhr = new XMLHttpRequest();

    //This is a bit tricky, [].fn.call(form.elements, ...) allows us to call .fn
    //on the form's elements, even though it's not an array. Effectively
    //Filtering all of the fields on the form
    var params = [].filter.call(form.elements, function(el) {
        //Allow only elements that don't have the 'checked' property
        //Or those who have it, and it's checked for them.
        return typeof(el.checked) === 'undefined' || el.checked;
        //Practically, filter out checkboxes/radios which aren't checekd.
    })
    .filter(function(el) { return !!el.name; }) //Nameless elements die.
    .filter(function(el) { return el.disabled; }) //Disabled elements die.
    .map(function(el) {
        //Map each field into a name=value string, make sure to properly escape!
        return encodeURIComponent(el.name) + '=' + encodeURIComponent(el.value);
    }).join('&'); //Then join all the strings by &

    xhr.open("POST", url);
    // Changed from application/x-form-urlencoded to application/x-form-urlencoded
    xhr.setRequestHeader("Content-type", "application/x-www-form-urlencoded");

    //.bind ensures that this inside of the function is the XHR object.
    xhr.onload = callback.bind(xhr); 

    //All preperations are clear, send the request!
    xhr.send(params);
}

所有主流浏览器以及IE9及以上版本均支持上述功能.

Answer 2

这是一个非常好的功能,我用它来做你正在尝试做的事情:

HTML:

<form action="/cs/Satellite">...</form>
<input type="button" value="Vote now" onclick="javascript:AJAXPost(this)">

JS:

function AJAXPost(myself) {
    var elem   = myself.form.elements;
    var url    = myself.form.action;    
    var params = "";
    var value;

    for (var i = 0; i < elem.length; i++) {
        if (elem[i].tagName == "SELECT") {
            value = elem[i].options[elem[i].selectedIndex].value;
        } else {
            value = elem[i].value;                
        }
        params += elem[i].name + "=" + encodeURIComponent(value) + "&";
    }

    if (window.XMLHttpRequest) {
        // code for IE7+, Firefox, Chrome, Opera, Safari
        xmlhttp=new XMLHttpRequest();
    } else { 
        // code for IE6, IE5
        xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
    }

    xmlhttp.open("POST",url,false);
    xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
    xmlhttp.setRequestHeader("Content-length", params.length);
    xmlhttp.setRequestHeader("Connection", "close");
    xmlhttp.send(params);

    return xmlhttp.responseText;
}

Answer 3

现在使用FormData是最简单的方法。您使用对Form元素的引用来构造它，它会为您序列化所有内容。

MDN在这里有一个例子——大致如下：

const form = document.querySelector("#debarcode-form");
form.addEventListener("submit", e => {
    e.preventDefault();
    const fd = new FormData(form);
    const xhr = new XMLHttpRequest();
    xhr.addEventListener("load", e => {
        console.log(e.target.responseText);
    });
    xhr.addEventListener("error", e => {
        console.log(e);
    });
    xhr.open("POST", form.action);
    xhr.send(fd);
});

如果你想把它作为一个对象（JSON）：

const obj = {};
[...fd.entries()].forEach(entry => obj[entry[0]] = entry[1]);

Answer 4

策略是序列化表单并使用 XHR 发送数据，然后对响应执行您想要的操作。Matt Krus 的Ajax Toolbox和相关的Javascript Toolbox提供了一组很好的实用程序和帮助。

如果您只是序列化发布的表单，那么以下内容就可以解决问题。它可以轻松扩展以包含其他表单控件类型：

var serialiseForm = (function() {

  // Checkboxes that have already been dealt with
  var cbNames;

  // Return the value of a checkbox group if any are checked
  // Otherwise return empty string
  function getCheckboxValue(cb) {
    var buttons = cb.form[cb.name];
    if (buttons.length) {
      for (var i=0, iLen=buttons.length; i<iLen; i++) {
        if (buttons[i].checked) {
          return buttons[i].value;
        }
      }
    } else {
      if (buttons.checked) {
        return buttons.value;
      }
    }
    return '';
  }

  return function (form) {
    var element, elements = form.elements;
    var result = [];
    var type;
    var value = '';
    cbNames = {};

    for (var i=0, iLen=elements.length; i<iLen; i++) {
      element = elements[i];
      type = element.type;

      // Only named, enabled controls are successful
      // Only get radio buttons once
      if (element.name && !element.disabled && !(element.name in cbNames)) {

         if (type == 'text' || type == 'hidden') {
          value = element.value;

        } else if (type == 'radio') {
          cbNames[element.name] = element.name;
          value = getCheckboxValue(element);

        }
      }

      if (value) {
        result.push(element.name + '=' + encodeURIComponent(value));
      }
      value = '';

    }
    return '?' + result.join('&');
  }
}());