JQuery and PHP Infinite Scrolling Help - php

I'm having a problem with my infinite scrolling. As I scroll down, it loads the next items fine but it keeps sending those items. I've been using this jquery to give it a unique id because I have ordered the items with mysql with an algorithm:
$("#image-list li").each(function(index) {
$(this).attr('id', index);
});
and inorder to label the newly given items from an external php file, I have to use this code in the file as well.
To send the information about the items given, I've been using this jquery:
function last_db_item_function()
{
var ID=$(".db-item:last").attr("id");
$('div#last-db-item-loader').html('<img src="loading.gif" height="30px" />');
$.post("index.php?action=get&last_db_item="+ID,
function(data){
if (data != "") {
$(".db-item:last").after(data);
}
$('div#last-db-item-loader').empty();
});
};
$(window).scroll(function(){
if ($(window).scrollTop() == $(document).height() - $(window).height()){
last_db_item_function();
}
});
but the problem is that it does not seem to work. Which I mean it doesn't not gather that last item id from the newly parsed php file. To parse the php I've been doing this:
$last_db_item = $_GET['last_db_item'];
$action = $_GET['action'];
if($action != "get")
{
.... Code Here....
}else{
include ('secondimages.php');
}
So my question is, why does this seem to go on forever?

It looks like you're never assigning a new ID to the new elements when you append them to the list. The first snippet you have either needs to be called after every new element is added, or similar code needs to be applied to that one element when you add it (unless it's coming back in the php, at which point we'd need to know more about what you're returning)

Related

Setting checkbox state correctly

I'm hoping I'm on the right track here....
I have some elements on my page (tables).. that are dynamically generated based on the results of querying a DB.... (I add inside of a container DIV)..
inside these tables are some text..and a handful of checkboxes... each table is the same (outside of the value of the text fields)..
When a user clicks on a checkbox.. I add an element to another container DIV off to the side.
If a user un-checks the checkbox.. it removes the element from the container DIV on the side. On each 'click' event..... I am also either adding or removing the 'selections' from an ARRAY (and also updating this array to my PHP SESSION)..
When the user is done.. they click a button and go to another page.. where this SESSION array is grabbed and reviews/summarizes their 'choices'..
*there is no FORM tags.. checkboxes are free-form in the tables (not wrapped in any FORM tags..so there is NO general POST action to grab everything.. hence the use of an array/SESSION)
If the user goes BACK to the original 'selection page' (with the tables/checkboxes)..
I am re-populating the PAGE (both re-checking any checkboxes...and re-populating the elements in the container DIV to the side.. all based on the SESSION data)
In each checkbox.. I am adding a little PHP function to write in checked="checked" or not.. when the checkboxes instantiate)
like so:
<label><input id="articlesnaming" name="Articles Naming Expert" type="checkbox" value="0.00" <?=sessionCheck($row["id"] ."-A","Articles Naming Expert") ?> onclick=""/> Articles Naming Expert</label>
FYI: on the function being called:
function sessionCheck($recordID, $checkBoxID){
if(isset($_SESSION['userPicks']) && count($_SESSION['userPicks']) != 0){
for($r = 0; $r< count($_SESSION['userPicks']); $r++){
if($_SESSION['userPicks'][$r]['recordid'] == $recordID){
for($z=0; $z < count($_SESSION['userPicks'][$r]['itemsordered']); $z++){
if($_SESSION['userPicks'][$r]['itemsordered'][$z]['name'] == $checkBoxID){
return 'checked="checked"';
}else if($z == (count($_SESSION['userPicks'][$r]['itemsordered']) - 1)){
return "";
}
}
}else if($r == (count($_SESSION['userPicks']) - 1)){
return "";
}
}
}else{
return "";
}
}
Everything up to this point works fine...
Its when I go to dynamically build/add (append) those elements in the container DIV on the side... where problems happen.
I am getting them added just fine and when a user RE-VISITS the page.. previous checkboxes they had selected were/are checked again... -and-.. the elements ARE in the container DIV to the side of the stage/screen)...
PROBLEM: When I un-check one of the checkboxes, it DOES NOT remove the element in the container DIV on the side? I have to re-click the checkbox..(which adds a duplicate).. then I can un-check it.. but it only removes the NEW one..
Everything seems to work fine until a refresh/re-visit of the page (and I have to automatically populate the checkboxes and the elements in the container DIV on the side).. then the checkboxes stop behaving/interacting with the elements that were adding through another function (still same ID's...paths..from what I can tell)....and -not- added through an initial checkbox event/action..
I am grasping at straws here.... it is perhaps because I'm using a PHP function to set the checkboxes on refresh? and it maybe doesn't know its current state? (although the visual state of the checkbox is accurate/correct)
Any ideas are appreciated.
Code used to set/un-set checkboxes & add/remove elements from the side container DIV :
<script>
//var to hold current check box clicked
var targetCheckbox;
//var to hold cumulative total
var totalPrice = 0;
//array to keep track of user picks from returned record results
//try to get SESSION array (if available/set) from PHP into jQuery using json_encode()
<?php if(isset($_SESSION['userPicks'])){ ?>
//overwrite jQuery userPicks MAIN array
var userPicks = <?php echo json_encode($tempArray) ?>;
<? }else{ ?>
//create new jQuery userPicks MAIN array, and populate through user clicks/interaction
var userPicks = [];
<? } ?>
$(document).ready(function() {
//check to see if seesion and populate checks and side column from previous picks
//if existing session, loop through and populate the CHOICES column
if(userPicks.length > 0){
console.log("SESSION EXISTS, POPULATE CHOICES COLUMN FROM ARRAY");
for(i=0; i<userPicks.length; i++){
//build up sub array data first then append at one time.
var subArrayLength = userPicks[i].itemsordered.length;
var subArray = '';
for(s=0; s<subArrayLength; s++){
subArray += '<li id="' + userPicks[i].orderid + userPicks[i].checkboxid + '">' + userPicks[i].itemsordered[s].name + '</li>';
}
$("#choicesWrapper #itemList").append('<div class="recordChoices"><h5>CASE NAME: '+userPicks[i].casename+'</h5><ul id="'+userPicks[i].recordid+'">'+subArray+'</ul></div>');
}
}
//onClick event
$('.orderOptions').on('click', 'input:checkbox', function () {
//routine when checkbox is checked
if ($(this).is(":checked")) {
$(this).prop("checked", true);
console.log("checked");
//console.log('doesnt exist..create it');
$("#choicesWrapper #itemList").append('<div class="recordChoices"><h5>CASE NAME: '+caseName+'</h5><ul id="'+resultsID+'"><li id="'+orderID+targetCheckbox+'">'+itemOrdered+'</li></ul></div>');
}else{
$(this).prop("checked", false);
console.log("un-checked");
//remove the option from right column (li element)
console.log("REMOVE TARGET: #choicesWrapper #itemList #"+resultsID+" "+orderID+targetCheckbox);
$("#choicesWrapper #itemList #"+resultsID+" #"+orderID+targetCheckbox).remove();
//check if no more children and remove parent/title (record container/div)
if ($("#choicesWrapper #itemList #"+resultsID+" li").length > 0) {
//console.log("Still has children...do nothing");
}else{
//console.log("No Children...");
$("#choicesWrapper #itemList #"+resultsID).parent().remove();
}
}
}
}
</script>
Oddly enough, when things are 'auto-populated' from the SESSION data (like on refresh or re-visiting the page) and when things 'break', unchecking the checkboxes doesn't remove things, but when I uncheck the very last checkbox in a group, it does remove the parent (so that parent removal code/routine is being executed...but not then child )
I'm thinking this is a pathing issue? (I believe I am creating things with exactly the same ID's/classes...etc).
Definitely worth the +1 if you answer! :)
The only other thing I can think of is.. HOW the userPicks array gets created.. initial visit to page, I just create an empty JS/jQuery array and wait to push/populate it when a user clicks a checkbox (code above for onClick stuff).
But when a user visits the page (refresh or re-visit) and -HAS- (previous) SESSION data still available.... then I grab the PHP SESSION array.. and pass it to jQuery using json_encode()...
Do I need to add/delete from that array differently than I do if I created normally?

Remove DIV only if empty

I have a PHP notification system, and the amount of notifications is put into a DIV using jQuery. The only problem is that when there are 0 notifications, the empty DIV still shows up. This is the jQuery I am currently using:
$(document).ready(function() {
$.get('/codes/php/nf.php', function(a) {
$('#nfbadge').html(a);
$('#nfbadge:empty').remove();
})
});
setInterval(function() {
$.get('http://localhost/codes/php/nf.php', function(a) {
$('#nfbadge').html(a);
$('#nfbadge:empty').remove();
})
}, 8000);
The only problem is that if at document load there is 0 notifications and a notification is added, the badge will not show up, so basically if the element is removed it won't come back unless the page is reloaded, but I made the notification system so that the page wouldn't have to be reloaded. How can I fix this?
.remove() takes the element out of the DOM as well as the content. This is why it doesn't come back unless you reload. Use .fadeOut() or .hide() instead
You should probably do something more like this:
var elm = $('#nfbadge'),
T = setInterval(getCodes, 8000);
function getCodes() {
$.get('/codes/php/nf.php', function(a) {
elm.html(a);
if (elm.is(':empty') && elm.is(':visible')) {
elm.hide();
}else{
elm.show();
}
});
}
Will need some more work on your part, but should get you on the right track!
If you have control over the PHP, you shouldn't be using jQuery to be removing DIVs, it's a waste of resources and load time, even if it's just a few lines of code.
In your PHP template you should include the #nfbadge div in a conditional statement, something like:
if($notifications) {
echo '<div id="nfbadge">';
//notification stuff
echo '</div>';
}
Then with your jQuery code you could do something like the following:
var $nfbadge = $('#nfbadge');
if($nfbadge) {$nfbadge.html(a)}
Why don't you just make the div hidden?
http://www.randomsnippets.com/2008/02/12/how-to-hide-and-show-your-div/

How to check for contents of a loaded div tag using jquery load?

I'm working with jqueries address change event and am hitting a roadblock when a user copies and pastes a URL in the browser. I need to fist load a portion of the page that contains a form. I could do this after every pagination call but it seems really ineffecient.
Here is my current code block:
$.address.change(function(e) {
var urlAux = e.value.split('=');
var page = urlAux[0];
var start = urlAux[1];
if (page == "/visits") {
$.address.title("Profile Views");
if (start) {
$('#start').val(start);
// ***** If a user has copied and pasted this URL with a start value then I first need to load visits.php in the main div tag. Is it possible to see if this is loaded or not?
$.post("visits_results.php", $("#profile_form_id").serialize(),
function(data) {
$('#search_results').html(data);
location.href = "#visits=" + start;
});
}
else {
var args = localStorage.getItem("visits");
$('#main').load("visits.php?" + args, function () { });
}
}
My attempted work around was this:
var args = localStorage.getItem("visits");
$('#main').load("visits.php?" + args, function () {
$('#start').val(start);
$.post("visits_results.php", $("#profile_form_id").serialize(),
function(data) {
$('#search_results').html(data);
location.href = "#visits=" + start;
});
});
There must be a better way...this is realoading the same portion of the page (visits.php) with every pagination event. Is there a better way to load URLs and not have them trigger an address change?
Using paul's work around from his comments, but instead of Regex'ing html content in the visits.php form this solution will look for data() attached to #mainID.
Paul's work around notes:
After a bit more hacking I came up with this solution that seems to do
the trick. I'm not sure how good it is but it seems to do the trick. I
now get the main div id and do a regex match on a unique string in the
form. If I don't see it I load the form and then load the results. Not
sure if this is good practice or not but it seems to solve my issue.
Methodology to use .data() instead of a regex search of visits.php's html:
/*check if we're missing visits.php by looking for data() flag*/
if( !($("#main").data()["hasVisitsPhp"]) ){
var args = localStorage.getItem("visits");
$('#main').load("visits.php?" + args, function () {
$('#start').val(start);
$.post("visits_results.php", $("#profile_form_id").serialize(),
function(data) {
/* we've loaded visits.php, set the data flag on #main*/
$('#main').data("hasVisitsPhp","loaded");
$('#search_results').html(data);
location.href = "#visits=" + start;
});
});
}
try window.location.hash instead. Changing the whole href can/will trigger a whole-page reload, while changing just the hash by itself should at most cause the page to scroll.

jQuery (ajax) $.get method delayed results

i'm using $.get() to get some elements from a php script and then show the results by "writing" them into a div. This is done periodically, as well as when the div is clicked or when the page reloads. Here's the code:
function fetchnew(){
var status = $J.cookie("status_on");
if (status == 'on'){
//fetch new items
//results from new-items.php have this format:
//<p>Item1</p><p>Item2</p>...
$J.get(modulebaselink+'new-items.php', '', function(newitems){
$J('#content').html(newitems);
updatestatus();
});
}
fetchnew_timeout = setTimeout('fetchnew();', refresh_rate);
}//end fetchnew()
function updatestatus(){
var status = $J.cookie("status_on");
if (status == 'on'){
//Show number of loaded items
var totalItems=$J('#content p').length;
$J('#status').html("Items ("+totalItems+")");
}
}
My problem is that the #status contents display with some delay after page reload. When the page loads i get 'Items(0)' for about ~1 sec, and then 0 changes to the real value. Is there any way to void the 'Items(0)' before displaying the real value? Or at least, cache the previous value and display 'Items(old_value)' instead of 'Items(0)' before the 'Items(new_value)' appears. I tried cookies to do the last one, but 'Items(0)' was there again...
Sounds like a reasonable usecase for the localStorage. Extend updatestatus() like this:
// this should be called at some entry point of your script
var ls_available = 'localStorage' in window;
if(ls_available && localStorage.getItem('totalItems'))
$J('#status').html("Items ("+localStorage.getItem('totalItems')+")");
function updatestatus(){
var status = $J.cookie("status_on");
if (chat_status == 'on'){
var totalItems=$J('#content p').length;
$J('#status').html("Items ("+totalItems+")");
if(ls_available) localStorage.setItem('totalItems', totalItems);
}
}
If your page (the one where fetchnew() is called) is rendered in PHP, call the same function that the Ajax file (new-items.php) calls. That way, your content is there immediately.

Printing results from function on page onclick?

Honestly, I'm not even sure the best way to go about this, but essentially, I have a function in an include file that takes a $type parameter and then will retrieve/print results from my db based on the $type passed into it... What I'm trying to do is have a series of links on a page that, when you click on a certain link, will run the function and display the results accordingly...
So, on the initial load of the page, there is a table that displays everything (and I'm simplifying the table greatly...)
<table>
<tr><th>Item</th><th>Type</th></tr>
<tr><td>Milk</td><td>Dairy</td></tr>
<tr><td>Yogurt</td><td>Dairy</td></tr>
<tr><td>Chicken</td><td>Meat</td></tr>
<tr><td>Zucchini</td><td>Vegetable</td></tr>
<tr><td>Cucumber</td><td>Vegetable</td></tr>
</table>
And, then, in a sidebar, I have a series of links:
Dairy
Meat
Vegetable
I'd like to filter the initial table (and back and forth, etc.) based on the link that is clicked, so that if the user clicks "Vegetable", the function from my include file will run and filter the table to show only "Vegetable" types...
The first idea that comes to mind is to add a class attribute to the <tr> tags and id attribs to the <a> tags so that you can easily filter that way:
<tr class="dairy"><td>Milk</td><td>Dairy</td></tr>
<tr class="meat"><td>Chicken</td><td>Meat</td></tr>
Dairy
Meat
Then in your JavaScript (I'm using jQuery here):
$('a').click(function(evt){
var myId = $(this).attr('id');
$('tr').each(function(idx, el){
if ($(el).hasClass(myId))
{
$(el).show();
}
else
{
$(el).hide();
}
});
});
This has the added benefit of allowing you to localize the text without having to change your code.
Ok I created a proper answer. You can do it the way Darrel proposed it. This is just an extension for the paging thing to avoid cookies:
$('a').click(function(evt){
var myId = $(this).attr('id');
// append a idndicator to the current url
var location = "" + document.location + "";
location = location.split('#',1);
document.location = location + '#' + $(this).attr('id');
//append to next and previous links
$('#nextlink').attr({
'href': $('#nextlink').attr('href') + '#' + $(this).attr('id')
});
$('#previouslink').attr({
'href': $('#previouslink').attr('href') + '#' + $(this).attr('id')
});
$('tr').each(function(idx, el){
if ($(el).hasClass(myId))
{
$(el).show();
}
else
{
$(el).hide();
}
});
});
Some code that is executed after page load:
var filter = window.location.hash ? '[id=' + window.location.hash.substring(1, window.location.hash.length) + ']' : false;
if(filter)
$('a').filter(filter).click();
This simulates/executes a click on page load on the link with the specific id.
But in general, if you have a large database, you should filter it directly with SQL in the backend. This would make the displayed table more consistent. For example if page 1 may only have 3 rows of class 'dairy' and on page 2 10 of class 'dairy'.
If youre printing out the whole tabel up front there is no need to go back to the server you can simple hide all teh rows of a given type. For example with jQuery:
$('#sidebar a').click(function(){
// grab the text content of the a tag conver to lowercase
var type = $(this).text().toLowerCase();
/* filter all the td's in the table looking for our specified type then hid the
* row that they are in
*/
$('#my_data_table td').contents().filter(function(){
return this.nodeType == 3 && this.toLowerCase() == type;
}).parent('tr').hide();
return false;
});
Really though the suggestion abotu adding a class to the TR is better because filtering on text content can get tricky if there is content youre not expecting for some reason (hence my conversion to all lower case to help with this).

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