PHP, jQuery (AJAX) - Refresh Information - php

Refresh information, only when it's new, not always.
Updating data just when differs from response.
<script>
$(document).ready(function(){
setInterval(function() {
$.ajax({
type : "POST",
url : "steam.php",
cache : false,
success : function(response) {
var parsedResponse = $.parseJSON(response);
$("#Display, [class='card-title display']").html(parsedResponse.display, parsedResponse.display);
$("#AvatarFull, #AvatarSmall").attr("src", parsedResponse.avatar, parsedResponse.savatar);
$("#Steam").attr("value", parsedResponse.display);
}
});
}, 1000)
});
</script>

You could achieve this by storing the response in a variable then comparing the new response. If they are the same, don't perform any action.
Also note that html() and attr() only accept one and two arguments respectively, so the last one in each call can be removed. In any case it's preferred practice to use prop() over attr(). In addition use val(), not attr() to update the value of a control. Try this:
$(document).ready(function() {
let lastResponse;
setInterval(function() {
$.ajax({
type: "POST",
url: "steam.php",
cache: false,
success: function(response) {
if (response != lastResponse) {
var parsedResponse = $.parseJSON(response);
$("#Display, [class='card-title display']").html(parsedResponse.display);
$("#AvatarFull, #AvatarSmall").prop("src", parsedResponse.avatar);
$("#Steam").val(parsedResponse.display);
lastResponse = response;
}
}
});
}, 1000)
});
With all that being said I'd strongly suggest you use the observer pattern for this instead of AJAX polling. This is because it puts far less strain on the server resources and you can configure it to only send updates when new information is available. If you want to know more about this research Websockets and SignalR.

Related

how to load data without page refresh using ajax

Here is my code for loading data
$(document).ready(function() {
$.get('get-answers.php', {
project_question_id: <?=$project_question_id?>,
project_id: <?=$project_id?>
}, function(data) {
$('#dispaly-answers').append(data);
});
});
This code retrieves data from database and working fine. But problem here is that if I add new data on the database, this data doesn't show up without page refresh.
So I don’t want to refresh the page to get the data. It should be displayed once new data added to database.
Any suggestions on this issue?
P.S : I also tried .ajax(), didn’t work.
Here is my $.ajax() request
$(document).ready(function() {
$.ajax( {
type: "GET",
url: "get-answers.php",
data: { project_question_id: <?=$project_question_id?>,
project_id: <?=$project_id?>
},
cache: false,
success: function(data) {
$('#dispaly-answers').append(data);
},// success
})// ajax
});
Does the same as $.get()
If your goal is to refresh the page data without refreshing the page, you can put your code in an interval timer and let it auto refresh every x seconds, like below.
setInterval(getAnswer(), 1000);
note: setInterval fires again and again until you clear it, while setTimeout only fires once.
The Ajax-Function get only called once: In the moment the document is ready (fully loaded). You have to use setTimeout to create a timer, which calls the function every minute or whatever you want. Like this:
function getData() {
setTimeout(function(){
$.get('get-answers.php', {
project_question_id: <?=$project_question_id?>,
project_id: <?=$project_id?>
}, function(data) {
$('#dispaly-answers').append(data);
getData();
});
}, 3000);
}
Here is my final approach
$(document).ready(function() {
setInterval(function(){
$.ajax( {
type: "GET",
url: "get-answers.php",
data: { project_question_id: <?=$project_question_id?>,
project_id: <?=$project_id?>
},
cache: false,
success: function(data) {
$('#dispaly-answers').html(data);
},// success
})// ajax
}, 1000);
});
Without creating and calling function getData(), this code working fine. Also I have changed .append(data) to .html(data).
But still I'm not happy with my code because it is constantly retrieving data from database that makes data server busy.
Whatever I wanted to tasks has to be done and it is done.
Try this you just need to replace this file retrieve_query.php and this id query-div with yours.
setInterval(function(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
$('#query-div').html(this.responseText);
}
};
xmlhttp.open("GET","retrieve_query.php",true);
xmlhttp.send();
},1000);

Wait until ajax request is done before each() jquery continue

I'm using Jquery ajax to check registration form.
this is my code:
$("input.register_input").each(function() {
name= this.name;
$(".ono#"+name).html("<img src='images/ajax-loader.gif'>");
if (name == 're_password') {
var dts = this.name+"="+$(this).val()+"&pass="+$("input[name='password']").val();
} else {
var dts = this.name+"="+$(this).val();
}
$.ajax({
type: "POST",
url: "ajc/register_check.php",
data: dts,
success: function(resultfrompage){
$(".ono#"+name).html(resultfrompage);
}
});
});
This is after user submitting the form. so I can't check all values at once.
I dont completly sure if that's the problem, but I this the each() loop is running before the ajax request is done so I'm getting only 1 value (last one) back. and all the rest still showing ajax-loader.gif.
This is the reason for the problem? and if so how can I fix it?
thank you!
Try t use async:false.
By default, all requests are sent asynchronously (i.e. this is set to
true by default). If you need synchronous requests, set this option to
false. Cross-domain requests and dataType: "jsonp" requests do not
support synchronous operation. Note that synchronous requests may
temporarily lock the browser, disabling any actions while the request
is active. As of jQuery 1.8, the use of async: false with jqXHR
($.Deferred) is deprecated; you must use the success/error/complete
callback options instead of the corresponding methods of the jqXHR
object such as jqXHR.done() or the deprecated jqXHR.success().
$("input.register_input").each(function() {
name= this.name;
$(".ono#"+name).html("<img src='images/ajax-loader.gif'>");
if (name == 're_password') {
var dts = this.name+"="+$(this).val()+"&pass="+$("input[name='password']").val();
} else {
var dts = this.name+"="+$(this).val();
}
$.ajax({
type: "POST",
async: false,
url: "ajc/register_check.php",
data: dts,
success: function(resultfrompage){
$(".ono#"+name).html(resultfrompage);
}
});
});
I suggest you to show some loading image while the Ajax request is processed. This way the user will understand that something is going on in the background. When this process will be finished handle the response.

Issue with using a value in JQuery/Javascript

I have a PHP populated table from Mysql and I am using JQuery to listen if a button is clicked and if clicked it will grab notes on the associated name that they clicked. It all works wonderful, there is just one problem. Sometimes when you click it and the dialog(JQuery UI) window opens, there in the text area there is nothing. If you are to click it again it will pop back up. So it seems sometimes, maybe the value is getting thrown out? I am not to sure and could use a hand.
Code:
$(document).ready(function () {
$(".NotesAccessor").click(function () {
notes_name = $(this).parent().parent().find(".user_table");
run();
});
});
function run(){
var url = '/pcg/popups/grabnotes.php';
showUrlInDialog(url);
sendUserfNotes();
}
function showUrlInDialog(url)
{
var tag = $("#dialog-container");
$.ajax({
url: url,
success: function(data) {
tag.html(data).dialog
({
width: '100%',
modal: true
}).dialog('open');
}
});
}
function sendUserfNotes()
{
$.ajax({
type: "POST",
dataType: "json",
url: '/pcg/popups/getNotes.php',
data:
{
'nameNotes': notes_name.text()
},
success: function(response) {
$('#notes_msg').text(response.the_notes)
}
});
}
function getNewnotes(){
new_notes = $('#notes_msg').val();
update(new_notes);
}
// if user updates notes
function update(new_notes)
{
$.ajax({
type: "POST",
//dataType: "json",
url: '/pcg/popups/updateNotes.php',
data:
{
'nameNotes': notes_name.text(),
'newNotes': new_notes
},
success: function(response) {
alert("Notes Updated.");
var i;
$("#dialog-container").effect( 'fade', 500 );
i = setInterval(function(){
$("#dialog-container").dialog( 'close' );
clearInterval(i);
}, 500);
}
});
}
/******is user closes notes ******/
function closeNotes()
{
var i;
$("#dialog-container").effect( 'fade', 500 );
i = setInterval(function(){
$("#dialog-container").dialog( 'close' );
clearInterval(i);
}, 500);
}
Let me know if you need anything else!
UPDATE:
The basic layout is
<div>
<div>
other stuff...
the table
</div>
</div>
Assuming that #notes_msg is located in #dialog-container, you would have to make sure that the actions happen in the correct order.
The best way to do that, is to wait for both ajax calls to finish and continue then. You can do that using the promises / jqXHR objects that the ajax calls return, see this section of the manual.
You code would look something like (you'd have to test it...):
function run(){
var url = '/pcg/popups/grabnotes.php';
var tag = $("#dialog-container");
var promise1 = showUrlInDialog(url);
var promise2 = sendUserfNotes();
$.when(promise1, promise2).done(function(data1, data2) {
// do something with the data returned from both functions:
// check to see what data1 and data2 contain, possibly the content is found
// in data1[2].responseText and data2[2].responseText
// stuff from first ajax call
tag.html(data1).dialog({
width: '100%',
modal: true
}).dialog('open');
// stuff from second ajax call, will not fail because we just added the correct html
$('#notes_msg').text(data2.the_notes)
});
}
The functions you are calling, should just return the result of the ajax call and do not do anything else:
function showUrlInDialog(url)
{
return $.ajax({
url: url
});
}
function sendUserfNotes()
{
return $.ajax({
type: "POST",
dataType: "json",
url: '/pcg/popups/getNotes.php',
data: {
'nameNotes': notes_name.text()
}
});
}
It's hard to tell from this, especially without the mark up, but both showUrlInDialog and sendUserfNotes are asynchronous actions. If showUrlInDialog finished after sendUserfNotes, then showUrlInDialog overwrites the contents of the dialog container with the data returned. This may or may not overwrite what sendUserfNotes put inside #notes_msg - depending on how the markup is laid out. If that is the case, then it would explains why the notes sometimes do not appear, seemingly randomly. It's a race condition.
There are several ways you can chain your ajax calls to keep sendUserOfNotes() from completing before ShowUrlInDialog(). Try using .ajaxComplete()
jQuery.ajaxComplete
Another ajax chaining technique you can use is to put the next call in the return of the first. The following snippet should get you on track:
function ShowUrlInDialog(url){
$.get(url,function(data){
tag.html(data).dialog({width: '100%',modal: true}).dialog('open');
sendUserOfNotes();
});
}
function sendUserOfNotes(){
$.post('/pcg/popups/getNotes.php',{'nameNotes': notes_name.text()},function(response){
$('#notes_msg').text(response.the_notes)
},"json");
}
James has it right. ShowUrlInDialog() sets the dialog's html and sendUserOfNotes() changes an element's content within the dialog. Everytime sendUserOfNotes() comes back first ShowUrlInDialog() wipes out the notes. The promise example by jeroen should work too.

Why won't my .ajax request work?

The code I want to work:
$.ajax({
type: "POST",
url: "_Source/ajap/ajap.nlSrch.php",
data: { sndJson : jsonData },
dataType: "json",
processData: false,
success: function(html) {
$("#srchFrm").append(html);}
});
The code that works:
$.ajax({
type: "POST",
url: "_Source/ajap/ajap.nlSrch.php",
data: { sndJson : jsonData },
success: function(html) {
$("#srchFrm").append(html);}
});
Unfortunately when I send the first one my post data looks like this "Array ()" and when I use the later I get this "Array ( [sndJson] => [\"8\",\"3\",\"6\",\"7\"] )".
I know that there has to be a simple explanation but I haven't been able to figure it out.
Help please!
Try sending your data in a query string...
$.ajax({
type:"POST",
url:"_Source/ajap/ajap.nlSrch.php?json="+jsonData,
dataType:"json",
success: function(data) {
$("#srchFrm").append(data);}
error: function(xhr, ajaxOptions, thrownError)
{alert("Error!");}
});
You can use shorthand $.post instead of using low level ajax class --- because you don't need to advanced handling. So, this one will be great enough.
$(document.ready(function(){
$("#submit_button").click(function(){
$.post('php_script.php', {
// here's what you want to send
// important -- double quotes, 'cause It's evals as valid JSON
"var1" : "val1"
"var2" : "val2"
}, function (respond){
try {
var respond = JSON.parse(respond);
} catch(e){
//error - respond wasn't JSON
}
});
});
});
PHP code:
<?php
/**
* Here you can handle variable or array you got from JavaScript
* and send back if need.
*/
print_r($_POST); // var1 = val1, var2 = val2
?>
Back to your question,
Why my .ajax request doesn't work?
This is because JavaScript throws fatal error and stops further code execution.
You can catch and determine the error occasion, simply by adding
try {} catch(){} block to the statement you think may occur any error
When you specify dataType: json, jQuery will automatically evaluate the response and return a Javascript object, in this case an array. You're taking the result and adding it as html to #srchForm, so it does not make sense to convert it to a javascript object. Use dataType: html, or none at all.
http://api.jquery.com/jQuery.ajax/
The following examples above are not reusable. I am a huge fan of reuseable code. here is my solution.
Software design 101:
DRY Don't repeat your self. You should wrap your code into an object. This way you can call it from anywhere.
var Request = {
version: 1.0, //not needed but i like versioning things
xproxy: function(type, url, data, callback, timeout, headers, contentType)
{
if (!timeout || timeout <= 0) { timeout = 15000; }
$.ajax(
{
url: url,
type: type,
data: data,
timeout: timeout,
contentType: contentType,
success:function(data)
{
if (callback != undefined) { callback(data); }
},
error:function(data)
{
if (callback != undefined) { callback(data); }
},
beforeSend: function(xhr)
{
//headers is a list with two items
if(headers)
{
xhr.setRequestHeader('secret-key', headers[0]);
xhr.setRequestHeader('api-key', headers[1]);
}
}
});
}
};
Usage:
<script type="text/javascript">
var contentType = "applicaiton/json";
var url = "http://api.lastfm.com/get/data/";
var timeout = 1000*5; //five seconds
var requestType = "POST"; //GET, POST, DELETE, PUT
var header = [];
header.push("unique-guid");
header.push("23903820983");
var data = "{\"username\":\"james\"}"; //you should really deserialize this w/ a function
function callback(data)
{
//do logic here
}
Request.xproxy(requestType, url, data, callback, timeout, header, contentType);
</script>

Workaround possible for cURL and Javascript?

Everything was going great in my previous help request thread. I was on the correct track to get around a CSRF, but needed to be pointed in the right direction. I received great help and even an alternate script used to log into Google's Android Market. Both my script and the one I altered to match my form is get hung up at the same point. Apparently cURL cannot process JS, is there any way to work around the form being submitted with submitForm() without changing the form?
Here is the code for the SubmitForm function
function submitForm(formObj, formMode) {
if (!formObj)
return false;
if (formObj.tagName != "FORM") {
if (!formObj.form)
return false;
formObj = formObj.form;
}
if (formObj.mode)
formObj.mode.value = formMode;
formObj.submit();
}
Here is the code for the submit button -
<a class="VertMenuItems" href="javascript: document.authform.submit();">Submit</a>
Here is a link to my last question in case more background information is needed.
PHP service...
<?php
// PHP service file
// Get all data coming in via GET or POST
$vars = $_GET + $_POST;
// Do something with the data coming in
?>
Javascript elsewhere...
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script type="text/javascript">
$(document).ready(function(){
function sendData(data)
{
var response;
$.ajax({
url: 'phpservice.php',
data: data,
type: 'POST',
dataType: 'json',
async: false,
success: function(response_from_service)
{
response = response_from_service;
},
error: function()
{
}
});
return response;
};
function getData(data)
{
var response;
$.ajax({
url: 'phpservice.php',
data: data,
type: 'GET',
dataType: 'json',
async: false,
success: function(response_from_service)
{
response = response_from_service;
},
error: function()
{
}
});
return response;
};
});
</script>

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