Current Setup
I have an HTML form like so.
<form id="demo-form" action="post-handler.php" method="POST">
<input type="text" name="name" value="previousValue"/>
<button type="submit" name="action" value="dosomething">Update</button>
</form>
I may have many of these forms on a page.
My Question
How do I submit this form asynchronously and not get redirected or refresh the page? I know how to use XMLHttpRequest. The issue I have is retrieving the data from the HTML in javascript to then put into a post request string. Here is the method I'm currently using for my zXMLHttpRequest`'s.
function getHttpRequest() {
var xmlhttp;
if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
xmlhttp=new XMLHttpRequest();
} else {// code for IE6, IE5
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
return xmlhttp;
}
function demoRequest() {
var request = getHttpRequest();
request.onreadystatechange=function() {
if (request.readyState == 4 && request.status == 200) {
console.log("Response Received");
}
}
request.open("POST","post-handler.php",true);
request.setRequestHeader("Content-type","application/x-www-form-urlencoded");
request.send("action=dosomething");
}
So for example, say the javascript method demoRequest() was called when the form's submit button was clicked, how do I access the form's values from this method to then add it to the XMLHttpRequest?
EDIT
Trying to implement a solution from an answer below I have modified my form like so.
<form id="demo-form">
<input type="text" name="name" value="previousValue"/>
<button type="submit" name="action" value="dosomething" onClick="demoRequest()">Update</button>
</form>
However, on clicking the button, it's still trying to redirect me (to where I'm unsure) and my method isn't called?
Button Event Listener
document.getElementById('updateBtn').addEventListener('click', function (evt) {
evt.preventDefault();
// Do something
updateProperties();
return false;
});
The POST string format is the following:
name=value&name2=value2&name3=value3
So you have to grab all names, their values and put them into that format.
You can either iterate all input elements or get specific ones by calling document.getElementById().
Warning: You have to use encodeURIComponent() for all names and especially for the values so that possible & contained in the strings do not break the format.
Example:
var input = document.getElementById("my-input-id");
var inputData = encodeURIComponent(input.value);
request.send("action=dosomething&" + input.name + "=" + inputData);
Another far simpler option would be to use FormData objects. Such an object can hold name and value pairs.
Luckily, we can construct a FormData object from an existing form and we can send it it directly to XMLHttpRequest's method send():
var formData = new FormData( document.getElementById("my-form-id") );
xhr.send(formData);
The ComFreek's answer is correct but a complete example is missing.
Therefore I have wrote an extremely simplified working snippet:
<!DOCTYPE html>
<html>
<head>
<meta http-equiv="X-UA-Compatible" content="IE=Edge, chrome=1"/>
<script>
"use strict";
function submitForm(oFormElement)
{
var xhr = new XMLHttpRequest();
xhr.onload = function(){ alert(xhr.responseText); }
xhr.open(oFormElement.method, oFormElement.getAttribute("action"));
xhr.send(new FormData(oFormElement));
return false;
}
</script>
</head>
<body>
<form method="POST"
action="post-handler.php"
onsubmit="return submitForm(this);" >
<input type="text" value="previousValue" name="name"/>
<input type="submit" value="Update"/>
</form>
</body>
</html>
This snippet is basic and cannot use GET. I have been inspired from the excellent Mozilla Documentation. Have a deeper read of this MDN documentation to do more. See also this answer using formAction.
By the way I have used the following code to submit form in ajax request.
$('form[id=demo-form]').submit(function (event) {
if (request) {
request.abort();
}
// setup some local variables
var $form = $(this);
// let's select and cache all the fields
var $inputs = $form.find("input, select, button, textarea");
// serialize the data in the form
var serializedData = $form.serialize();
// fire off the request to specific url
var request = $.ajax({
url : "URL TO POST FORM",
type: "post",
data: serializedData
});
// callback handler that will be called on success
request.done(function (response, textStatus, jqXHR){
});
// callback handler that will be called on failure
request.fail(function (jqXHR, textStatus, errorThrown){
});
// callback handler that will be called regardless
// if the request failed or succeeded
request.always(function () {
// reenable the inputs
});
// prevent default posting of form
event.preventDefault();
});
With pure Javascript, you just want something like:
var val = document.getElementById("inputFieldID").value;
You want to compose a data object that has key-value pairs, kind of like
name=John&lastName=Smith&age=3
Then send it with request.send("name=John&lastName=Smith&age=3");
I have had this problem too, I think.
I have a input element with a button. The onclick method of the button uses XMLHTTPRequest to POST a request to the server, all coded in the JavaScript.
When I wrapped the input and the button in a form the form's action property was used. The button was not type=submit which form my reading of HTML standard (https://html.spec.whatwg.org/#attributes-for-form-submission) it should be.
But I solved it by overriding the form.onsubmit method like so:
form.onsubmit = function(E){return false;}
I was using FireFox developer edition and chromium 38.0.2125.111 Ubuntu 14.04 (290379) (64-bit).
function postt(){
var http = new XMLHttpRequest();
var y = document.getElementById("user").value;
var z = document.getElementById("pass").value;
var postdata= "username=y&password=z"; //Probably need the escape method for values here, like you did
http.open("POST", "chat.php", true);
//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", postdata.length);
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
alert(http.responseText);
}
}
http.send(postdata);
}
how can I post the values of y and z here from the form
Related
I have a form that passes various types of input to an ajax call, which opens a php script. The script will do various things including processing the file, before echoing an array of variables.
All inputs go through $_POST regularly, and the file data is passed, too, but the file itself is not accessible from $_FILES.
I am not using jQuery, so most posts are hard to translate to my case.
I have seen a similar issue here,https://stackoverflow.com/questions/56878395/files-empty-after-ajax-upload but that solution doesn't seem to apply.
Here are the key excerpts from the code, thank you in advance for any tips!
var ajaxResponse = "";
var qForm = document.getElementById('myForm');
qForm.addEventListener("submit", function(e) {
e.preventDefault();
var formData = new FormData(qForm);
checkForm(formData);
console.log(ajaxResponse); //this shows the $_FILES var_dump
});
function checkForm(formData) {
var vars = "startDate=" + formData.get('startDate') +
"&qInvited=" + formData.get('qInvited');
ajaxRequestReturn("checkForm.php", vars);
}
function ajaxRequestReturn(phpRequest, vars) {
var req = new XMLHttpRequest();
req.open("POST", phpRequest, false); //not asynchronous, because I pass results to a global variable
req.setRequestHeader('Content-type', 'application/x-www-form-urlencoded'); //removing the setRequestHeader doesn't seem to make any difference.
req.onload = function() {
ajaxResponse = this.responseText;
}
req.onerror = function() {
throw new Error("Bad request.");
}
req.send(vars);
// form.submit();
}
<form class="loginForm" id="myForm" method="post" enctype="multipart/form-data" action="thisPage.php">
<div>
<input type="date" id="startDateInput" name="startDate">
</div>
<div>
<input type="file" name="qInvited" required>
</div>
<input type="submit" id="submitBtn">
</form>
and the checkForm.php file is currently simply:
<?php
echo var_dump($_FILES);
?>
the var_dump($_FILES) should show the qInvited file in it, but it prints
array(0) {
}
instead.
To upload a file via ajax you have to pass a FormData object in your call to XMLHttpRequest.send.
Get rid of the checkForm function and call ajaxRequestReturn with formData as the second parameter.
Also, application/x-www-form-urlencoded is not the correct content type(its multipart/form-data), remove that line. The correct content type will be set automatically when you use the FormData object.
Unable to get parameters passed from javascript to loginme.php
This is simple form in
index.php
<form method="POST">
<input type="text" id="userid" name="userid"></input>
<input type="password" id="pass" name="pass"></input>
<input type="button" value="Log in" onclick="letUserLogin()"/>
</form>
Javascript function :
myscript.js
function letUserLogin() {
var userid = document.getElementById("userid").value;
var pass = document.getElementById("pass").value;
if (window.XMLHttpRequest) {
xmlhttp=new XMLHttpRequest();
} else {
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function() {
if (xmlhttp.readyState==4 && xmlhttp.status==200) {
alert(xmlhttp.responseText); //only shows 'and'
}
}
xmlhttp.open("POST","loginme.php?userid="+userid+"&pass="+pass,true);
xmlhttp.send();
}
Simple echo statement in loginme.php
loginme.php
<?php
// username and password sent from form
$username=$_POST['userid'];
$password=$_POST['pass'];
echo"$username and $password";
?>
You are passing GET parameters:
xmlhttp.open("POST","loginme.php?userid="+userid+"&pass="+pass,true);
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
... thus you need to fetch them from $_GET, not $_POST:
$username=$_GET['userid'];
$password=$_GET['pass'];
You possibly want to use the send() method instead to send your data. Right now, your payload is empty:
xmlhttp.send();
You can resolve this with JQuery quite easily if you want:
This method also allows you to put the URL within the action parameter of the form and uses POST which is more secured for transferring password information:
JQUERY:
$(document).on('submit', "form", function(e){ //We add a listener
e.preventDefault();
$.post($(this).attr('action'), $(this).serialize())
.done( function( data ) {
//Do something with response
});
});
Note that you can of course change the listener to only listen to a specific form. In this case all forms submits will be caught rather than a specific one in a page.
HTML:
<form action="/path/to/loginme.php">
<input type="text" name="userid">
<input type="password" name="pass">
</form>
PHP:
$username=$_POST['userid'];
$password=$_POST['pass'];
echo "$username and $password";
You are using POST but explicitly setting the values into the query string, GET style. So basically you are sending a blank POST.
You need to send the values like this:
xmlhttp.open("POST","loginme.php", true);
xmlhttp.setRequestHeader("Content-type","application/x-www-form-urlencoded");
xmlhttp.send("userid=" + userid + "&pass=" + pass);
try this:
var userid =encodeURIComponent(document.getElementById("userid").value)
var pass =encodeURIComponent(document.getElementById("pass").value)
var parameters="userid="+userid+"&pass="+pass
mypostrequest.open("POST", "loginme.php", true)
mypostrequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded")
mypostrequest.send(parameters)
use of encodeURIComponent() to encode any special characters within the parameter values.
Call setRequestHeader() and set its content type to "application/x-www-form-urlencoded". This is needed for any POST request made via Ajax.
I have the following script, a few lines up from the bottom I have a window.location.href which posts the reults from my form though the address bar. This is very messy and I would like to use POST instead of GET, any ideas anyone ?
<script language="javascript">
function OnChangedUsername()
{
if(document.signup.newuserid.value == "")
{
document.signup.btnCheckAvailability.disabled = true;
}
else
{
document.signup.btnCheckAvailability.disabled = false;
}
}
function createRequestObject() {
var ro;
var browser = navigator.appName;
if(browser == "Microsoft Internet Explorer"){
ro = new ActiveXObject("Microsoft.XMLHTTP");
}else{
ro = new XMLHttpRequest();
}
return ro;
}
var http = createRequestObject();
function sndReq() {
http.open('get', 'password_check.asp?emailaddress=<%Response.Write(emailaddress)%>&check=<%Response.Write(check)%>&password_check='+document.signup.newuserid.value);
http.onreadystatechange = handleResponse;
http.send(null);
}
function handleResponse() {
if(http.readyState == 4){
var response = http.responseText;
var update = new Array();
if(response.indexOf('|' != -1)) {
update = response.split('|');
document.getElementById("username_chk").innerHTML = update[0];
if(document.getElementById("username_chk").innerHTML == "Ok") {
window.location.href='detailsupdate.asp?username=<%Response.Write(sUsername)%>&check=<%Response.Write(check)%>&EmailAddress='+document.signup.EmailAddress.value+'&Address='+document.signup.Address.value+'&Address1='+document.signup.Address1.value+'&Address2='+document.signup.Address2.value+'&City='+document.signup.City.value+'&PostalCode='+document.signup.PostalCode.value+'&Country='+document.signup.Country.value+'&WorkPhone='+document.signup.WorkPhone.value+'&HomePhone='+document.signup.HomePhone.value+'&MobilePhone='+document.signup.MobilePhone.value+'&FaxNumber='+document.signup.FaxNumber.value+'&AlternativePhone='+document.signup.AlternativePhone.value+'&OO='+document.signup.OO.checked+'&Workshop='+document.signup.Workshop.checked+'&Raised='+document.signup.Raised.checked+'&Ground='+document.signup.Ground.checked+'&pd='+document.signup.newuserid.value+'&Tram='+document.signup.Tram.checked;
}
}
}
}
</script>
The only way to make a POST request with the response rendered directly into the browser window is to use a form (which you generate with DOM) and submit it (which you can likewise do through DOM).
The alternative is to use XMLHttpRequest (or some other Ajax technique) and render the response with DOM.
There is no need to pass form data as GET data. You can specify the method as POST.
<form action="script.asp" method="post">
...
<input type="submit" value="submit">
</form>
You also should not be using window.location.href. This is very ugly. When you submit the form (click the submit button) it will POST your form data to script.asp.
Another way to submit your form is to submit it via DOM. document.forms[0].submit();
I am working on a ColdFusion 8 training application where I'm making some AJAX requests (without any libraries such as jQuery) to support a very basic CRUD application.
The high level architecture includes a CFM view, a CFC with remote access methods which receive the AJAX requests, and a CFC which acts as a model and has all of the database queries.
For just retrieving data that doesn't require any sort of bind variables (like getting all rows from the table), the AJAX queries are working fine. When I try to post anything to the CFC middle layer, however, I'm getting errors about the values I'm looking for being undefined in the Form scope (which from my understanding is where post parameters will be stored). I even dissected the requests with Tamper Data and verified that the names and values of the post parameters are as I expect them to be.
Here is an example of the JS AJAX requests:
function addLocation(locToAdd) {
var thisAccess = new AccessStruct("POST", "jsontest.cfc?method=addNewLocation", getLocations, "newLoc=" + JSON.stringify(locToAdd));
accessWrapper("addLoc", thisAccess);
function accessWrapper(action, accessDef) {
var ajaxRequest = new XMLHttpRequest();
var nextStep;
if (action != "getLocs") {
nextStep = getLocations;
} else {
nextStep = buildTable;
}
ajaxRequest.onreadystatechange = function() { // using a closure so that the callback can
if (ajaxRequest.readyState == 4) { // examine the request and nextStep
if (ajaxRequest.status == 200) {
if (nextStep != null) {
nextStep(ajaxRequest);
}
return true;
} else {
alert("Request Could Not Be Completed; Errors On Page");
return false;
}
}
}
ajaxRequest.open(accessDef.method, accessDef.url, true);
ajaxRequest.send("newLoc=" + accessDef.params);
}
function Loc(locCode, parLocCode, name, addrL1, addrL2,
city, stateProv, postal, locTypeCode) {
this.locCode = locCode;
this.parLocCode = parLocCode;
this.name = name;
this.addrL1 = addrL1;
this.addrL2 = addrL2;
this.city = city;
this.stateProv = stateProv;
this.postal = postal;
this.locTypeCode = locTypeCode;
}
function AccessStruct(method, url, nextStep, params) {
this.method = method;
this.url = url;
this.nextStep = nextStep;
this.params = params;
}
Essentially what's happening on the page is that a table populated by all the location (loc) records is being rendered for a "user". There is a form to add a new user, and when they click the add button, a Loc structure is created containing the information they entered and is passed to the addLocation function. This creates an Access structure, which will include the request URL, method, the name of a function to act as a callback, and any post parameters. This is all passed into the accessWrapper function, which will create the XMLHttpRequest and process the AJAX request. I used a closure for the onreadystatechange callback function so that it could be aware of the XMLHttpRequest object and the callback function defined in the Access structure (this callback function will be generally be used to refresh the view table after a record is added, deleted, or edited).
Here is the cffunction within the middle-layer CFC where the problem is being reported from. I won't bother to post the DAO CFC as that has been tested elsewhere and is not even being reached during this process (because it's failing at the middle [or controller] level)
<cffunction name="addNewLocation" output="false" access="remote">
<cfset var deserializedLocation = "">
<cfscript>
deserializedLocation = DeserializeJSON(Form.newLoc);
</cfscript>
<cfobject component="locationDAO" name="locationDAOObj">
<cfinvoke
component="#locationDAOObj#"
method="addLocation">
<cfinvokeargument name="code" value="#deserializedLocation.locCode#">
<cfinvokeargument name="parentCode" value="#deserializedLocation.parLocCode#">
<cfinvokeargument name="name" value="#deserializedLocation.name#">
<cfinvokeargument name="addr1" value="#deserializedLocation.addrL1#">
<cfinvokeargument name="addr2" value="#deserializedLocation.addrL2#">
<cfinvokeargument name="city" value="#deserializedLocation.city#">
<cfinvokeargument name="stateProv" value="#deserializedLocation.stateProv#">
<cfinvokeargument name="postal" value="#deserializedLocation.postal#">
<cfinvokeargument name="locationType" value="#deserializedLocation.locTypeCode#">
</cfinvoke>
</cffunction>
The error in the request response is:
500 Element NEWLOC is undefined in FORM
Like I said before, I've checked the request in Tamper Data, and it looks fine there. Thanks in advance for any help you great folks might be able to offer!
There absolutely is a FORM scope when you do an Ajax post to a CFC.
This example POSTs form data via Ajax to a CFC function with no arguments and returns the JSON format of the FORM scope. Yes, you should have arguments to document, specify required/not required and data type, but they're not mandatory.
Is there any reason you aren't using jQuery? It would probably make your life much easier.
There must be something wrong with how you're sending the form data to the Ajax call. If you use FireBug to watch your Ajax calls, you can see the POSTed parameters.
HTML
<html>
<head>
<title>Ajax POST to CFC</title>
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
<script type="text/javascript" src="test.js">
</head>
<body>
<form id="foo" action="" method="post">
<input type="text" id="a" name="a" value="Hello" />
<br />
<input type="text" id="b" name="b" value="Goodbye" />
<br />
<textarea id="data" cols="30" rows="10" disabled="true"></textarea>
<br />
<input type="button" id="btnSubmit" value="Do Ajax!" />
</form>
</body>
</html>
JavaScript
$(document).ready(function() {
$('#btnSubmit').on('click', function() {
$.ajax({
asynch : true,
type : 'POST',
dataType : 'json',
url : 'test.cfc?method=testing&returnformat=json',
data : {
a : $('#a').val(),
b : $('#b').val()
},
success : function(data, textStatus) {
$('#data').val(JSON.stringify(data));
}
});
});
});
CFC
<cfcomponent>
<cffunction name="testing" access="remote" output="false" returntype="string">
<cfreturn serializeJSON( form ) />
</cffunction>>
</cfcomponent>
Old School, no jQuery, just plain ol' JavaScript
I found a simple example of an Ajax POST without jQuery here:
http://www.openjs.com/articles/ajax_xmlhttp_using_post.php
HTML
Remove the jQuery SCRIPT tag, change the other SCRIPT to test-nojq.js and change the submit button to add an onclick event.
<input type="button" id="btnSubmit" value="Do Ajax!" onclick="doSubmit();" />
JavaScript: test-nojq.js
function doSubmit(){
var http = new XMLHttpRequest();
var url = "test.cfc";
var params = "method=testing&returnformat=json";
params += "&a=" + document.getElementById('a').value;
params += "&b=" + document.getElementById('b').value;
http.open("POST", url, true);
//Send the proper header information along with the request
http.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
http.setRequestHeader("Content-length", params.length);
http.setRequestHeader("Connection", "close");
http.onreadystatechange = function() {//Call a function when the state changes.
if(http.readyState == 4 && http.status == 200) {
document.getElementById('data').value = http.responseText;
}
}
http.send(params);
}
Make newLoc into an argument and it should work.
<cffunction name="addNewLocation" output="false" access="remote">
<cfargument name="newLoc">
...
</cffunction>
update: not sure why I encountered no form scope one time calling a remote method. Anyway, it isn't true but the rest of the answer should still hold true.
Here's how the situation looks :
I have a couple simple forms
<form action='settings.php' method='post'>
<input type='hidden' name='setting' value='value1'>
<input type='submit' value='Value1'>
</form>
Other small forms close to it have value2, value3, ... for the specific setting1, etc.
Now, I have all these forms placed on the settings.php subpage, but I'd also like to have copies of one or two of them on the index.php subpage (for ease of access, as they are in certain situations rather frequently used).
Thing is I do not want those forms based on the index.php to redirect me in any way to settings.php, just post the hidden value to alter settings and that's all.
How can I do this with JS ?
Cheers
Yes, you could use an ajax call to send a request to the settings.php file. You'd probably want that PHP code to return something that the JavaScript can use to know if the request was successful or not (for example, using JSON instead of HTML).
Here is an ajax getData function.
function getData(dataSource, targetDiv){
var XMLHttpRequestObject = false;
if (window.XMLHttpRequest) {
XMLHttpRequestObject = new XMLHttpRequest();
} else if (window.ActiveXObject) {
XMLHttpRequestObject = new
ActiveXObject("Microsoft.XMLHTTP");
}
if(XMLHttpRequestObject) {
var obj = document.getElementById(targetDiv);
XMLHttpRequestObject.open("GET", "settings.php?form="+dataSource+"&t="+new Date().getTime());
XMLHttpRequestObject.onreadystatechange = function()
{
if (XMLHttpRequestObject.readyState == 4 && XMLHttpRequestObject.status == 200) {
obj.innerHTML = XMLHttpRequestObject.responseText;
}
}
XMLHttpRequestObject.send(null);
}
}
use this function to send the form to your setting.php file which should return confirmation message to index.php(inside targetDiv).
Parameters of the function
1) dataSource - is the variable value that you send to settings.php
2) targetDiv - is the div on index php that with display the response from settings.php
Hope it makes sense.