最近做項目遇到用Javascript提交表單的問題, 之前也做過幾次, 但是不夠全面, 這次總結出了幾種用JavaScript提交表單的方式, 並且對此作出了比較, 選出了一種最適合此項目的方式。
我目前正在為Sun Communication Suite做一個創建用戶的小型系統,大家都知道我們可以通過表單,Ajax 和鏈接來訪問服務器, 最簡單的方法就是使用連接, 例如:<a href=UserServlet?event=SEARCH_MAILING_LIST¤tPage=1&keyword="+keyword+"&searchBy="+searchBy+"&cn="+request.getAttribute("cn")+">First Page</a>, 把所有需要的數據全部寫到超鏈接上, 如果你能夠觀察一下就會知道,在上邊的鏈接中只有currentPage是變化的, 其他參數event, keyword, searbyBy和cn是不變的, 那麼我就想到如果我能夠把這些不變的參數封裝到一個表單中, 當用戶點擊上面的超鏈接的時候我用JavaScript把這個表單提交, 那麼我自然會訪問到服務器。
表單:
<form name="pagination" id="pagination" action="UserServlet" method="get"> <input type="hidden" name="currentPage" value="1"/> <Input type="hidden" name="cn" value="<%=request.getAttribute("cn")%>"/> <input type="hidden" name="keyword" value="<%=request.getAttribute("keyword")%>"/> <input type="hidden" name="searchBy" value="<%=request.getAttribute("searchBy")%>"/> <input type="hidden" name="event" value="SEARCH_USER_FOR_MAILING_LIST"> </form>
在提交表單的過程中, 我只需要把參數currentPage傳給JavaScript就好了,所以我就把上面的連接改為下邊的形式:
<a href=# onclick=document.pagination.currentPage.value="+pages[j]+";document.pagination.submit();><span style='color: red;'>["+pages[j]+"]</span></a>
大家要注意一定要把document.pagination.currentPage.value="+pages[j]+";寫在document.pagination.submit();的前邊, 這樣在用戶提交表單之前, 參數currentPage就已經被修改為我們需要的數值。 這樣我就完成了用連接來提交表單, 但是我有遇到了一個問題, 我需要試用上面的這段代碼在很多頁面, 如果我能統一的寫一段JavaScript的話,就會方面我以後對整個系統做維護, 所以我幾寫了一個JavaScript的函數。
function submitForm(id,currentPage){ //var currentPage = document.pagination.currentPage.value; //alert(currentPage); //currentPage=100; //var currentPage = document.pagination.currentPage.value; //alert(currentPage); document.pagination.currentPage.value=currentPage; var form = document.getElementById(id); form.submit(); }
然後我在超連接的onclick事件上條用這個函數:
<a href=# onclick=submitForm('pagination',"+pages[j]+")>["+pages[j]+"]</a>, 大家可以看到整段代碼簡潔了不少。
所以我總結了一下,用Javascript提交表單大概有兩種寫法(根據我目前的理解)
1. document.formName.submit();
2. var form = document.getElementById(id);
form.submit();
下次我想和大家分享一下用JNDI實現分頁。我把這次的代碼附在下邊, 大家可以參考一下。
commons.js
function submitForm(id,currentPage){ //var currentPage = document.pagination.currentPage.value; //alert(currentPage); //currentPage=100; //var currentPage = document.pagination.currentPage.value; //alert(currentPage); document.pagination.currentPage.value=currentPage; var form = document.getElementById(id); form.submit(); }
mailingListMemberAdd.jsp
<%@page contentType="text/html" pageEncoding="UTF-8"%> <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <%@ page import="java.util.LinkedList" %> <%@ page import="java.util.Iterator" %> <%@ page import="java.util.ArrayList" %> <%@ page import="java.util.List" %> <%@ page import="my.gov.rmp.webmail.domain.User" %> <%@ page import="my.gov.rmp.webmail.util.Pager" %> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Add Member to Mailing List:<%=request.getAttribute("cn")%></title> <script type="text/javascript" src="../js/commons.js"></script> </head> <body> <jsp:include page="../inc/admin/headerMail.jsp"/> <div id="main"> <div id="contents" > <h2>Add new members to mailing list: <span style="color:blue;"><%=request.getAttribute("cn")%></span></h2> <form name="addMailingListMember" id="addMailingListMember" action="UserServlet" method="post"> <table cellspacing="5" cellpadding="5"> <% Pager pager =(Pager) request.getAttribute("pager"); int currentPage =pager.getCurrentPage(); int pageSize = pager.getPageSize(); int i=(currentPage-1)*pageSize; LinkedList users = (LinkedList)request.getAttribute("users"); if(!users.isEmpty()){ %> <tr style="font-weight:bold"><td>No. </td><td>UID:</td><td>gCode:</td><td>Givenname:</td><td>Surname:</td><td>Mail:</td><td>Description:</td></tr> <% for(Iterator iter = users.iterator();iter.hasNext();){ User user = (User) iter.next(); i++; // Attributes attrs = user.getAttrs(); %> <tr><td><%=i%>. <input type="checkbox" name="uid" value="<%=user.getUid()%>" /></td> <td width="15%"><%=user.getUid()%></td> <td><%=user.getGCode()%></td> <td><%=user.getGivenName()%></td> <td><%=user.getSn()%></td> <td width="30%"><%=user.getMail()%></td> <td><%if(user.getDescription()==null||user.getDescription().length()==0){%>Not Set<%} else %><%=user.getDescription()%></td> </tr> <% } %> <input type="hidden" name="cn" value="<%=request.getParameter("cn")%>"/> <input type="hidden" name="event" value="ADD_MAILING_LIST_MEMBER" /> <tr><td><button onclick="return selectAllCheckBoxs('uid');">Select All</button></td><td><button onclick="return deselectAllCheckBoxs('uid')">Deselect All</button></td><td></td><td><input type="submit" name="submit" value="Add to Mailing List"/></td></tr> </table> </form> <hr> <P STYLE="margin-top:-5px;"><strong>Pages:</strong> <form name="pagination" id="pagination" action="UserServlet" method="get"> <input type="hidden" name="currentPage" value="1"/> <Input type="hidden" name="cn" value="<%=request.getAttribute("cn")%>"/> <input type="hidden" name="keyword" value="<%=request.getAttribute("keyword")%>"/> <input type="hidden" name="searchBy" value="<%=request.getAttribute("searchBy")%>"/> <input type="hidden" name="event" value="SEARCH_USER_FOR_MAILING_LIST"> </form> <% int[] pages = pager.getPages(); String keyword = request.getAttribute("keyword").toString(); String searchBy = request.getAttribute("searchBy").toString(); if(pager.isHasFirst()){ out.println("<a href=UserServlet?event=SEARCH_USER_FOR_MAILING_LIST¤tPage=1&keyword="+keyword+"&searchBy="+searchBy+"&cn="+request.getAttribute("cn")+">First Page</a> "); } if(pager.isHasPrevious()){ out.println("<a href=# onclick=submitForm('pagination',"+(pager.getCurrentPage()-1)+")>Prev Page</a> "); } for(int j=0;j<pages.length;j++){ if(pager.getCurrentPage()==pages[j]){ out.println("<a href=# onclick=document.pagination.currentPage.value="+pages[j]+";document.pagination.submit();><span style='color: red;'>["+pages[j]+"]</span></a>"); }else { out.println("<a href=# onclick=submitForm('pagination',"+pages[j]+")>["+pages[j]+"]</a>"); } } if(pager.isHasNext()){ out.println("<a href=# onclick=submitForm('pagination',"+(pager.getCurrentPage()+1)+")>Next Page</a> "); } if(pager.isHasLast()){ out.println("<a href=# onclick=submitForm('pagination',"+pager.getTotalPage()+")>Last Page</a> "); } %> </P> <% } else { //make the mailing list member availabe when user are trying to re-run the search //request.setAttribute("members", members); %> <p>No results are matched your keyword or the user that you are looking for is already a member of this mailing list, please specify another keywork and <a href="<%=request.getContextPath()%>/admin/mailingListMemberSearch.jsp?cn=<%=request.getParameter("cn")%>">Search Again</a></p> <% } %> </div> </div> </body> </html>