Develop Reference

Showing results from JSON only when filter is selected

Objective
I want display results only when it's respective state is selected. Currently all results are shown by default when the page loads.
I do not want anything to load by default. When a state is selected then those results should populate.
Background
I have a location selection feature that I am working on at this CodePen.
It used MustacheJS for templating
and is populated by data in a JSON file by this script
$(function() {
$.getJSON('https://s3-us-west-2.amazonaws.com/s.cdpn.io/161741/labs.js', function(data) {
var template = $('#labsListStates').html();
var html = Mustache.to_html(template, data);
$('#states').html(html);
});
});
The results can be filtered by state with. It runs on this script
/* Filter for locations */
$('#lab-state-select').on('change', function (e) {
e.preventDefault();
var cat = $(this).val();
var nam = $(this).val();
$('#states > div').hide();
$('#states > div[data-category-type="'+cat+'"][data-category-name="'+nam+'"]').show();
});
Problems
I know that this is sloppy. I am not using pure JSON but actually creating a Javascript object. And even named the file to end with .js so that it would work. I read about how that is a bad practice at http://www.kryptonite-dove.com/blog/load-json-file-locally-using-pure-javascript
That taught me to look into a XMLHttpRequest. But even implementing that I am still confused how to display the data I need when I need it. I think I am on the correct track by looking into the
.on() but would appreciate some additional help.

You simply use $('#states > div').hide(); to hide the data right after you load the data: $('#states').html(html);.
You can check out the fork here: http://codepen.io/anon/pen/lBims
As for getting the JSON file, you can simply return it with any file type. You don't have to use a .js extension if it's just pure JSON output. And JSON is just a stringified representation for Javascript objects, so it's fine treating JSON as an object. In Fact that's what you're supposed to do. JSON = JavaScript Object Notation.

Get query string from URL with jQuery and do action based on that

I have a link in an e-mail that points the user to a webpage. On this webpage there is a pop-up that is hidden, unless a button is clicked; then jQuery displays that div.
I have searched for a way to grab the query string from the URL with jQuery to no avail. I know with PHP it would be a simple $query = $_GET['query'], but I'm not sure how to accomplish this with jQuery.
I need to check for a query string, say "?popUp=true", and display that div with jQuery if the query string is present.
Is there a way I can pass the PHP GET variable to jQuery?
I'm confused.

jQuery has nothing to do with it; it's just plain Javascript:
var query = window.location.search;
Or simply location.search. Do window.location from the Javascript console to see what all is there.
So:
$(document).ready(function(){
if (location.search.indexOf('popUp=true') > -1)) {
doPopUp(); // run your code.
}
});
MDN

Of course, we can get query parameter from url by split it, and it's pure java script. There's a general way to do it: http://www.jquerybyexample.net/2012/06/get-url-parameters-using-jquery.html
But if you just need [popup=true] to use with jquery, you'd better to use hash.
URL:
http://.../yourscript.php#popup
And your jquery code:
if(window.location.hash) {
// Fragment exists, show popup
} else {
// Fragment doesn't exist, do nothing
}

How to load blade or php content into a view via ajax/jquery in laravel?

As the title says, I am trying to dynamically load content in a view using ajax requests. I know this can be done if you are using html elements e.g. ("#div_place").html(<p>...). The problem lies when I would like to load some php/blade objects into a div for instance. Is this possible or is there a different way to go about achieving the result I want.

This is pretty straightforward. Assuming you're using jQuery...
create a route that will respond to the AJAX call and return an HTML fragment
Route::get('test', function(){
// this returns the contents of the rendered template to the client as a string
return View::make("mytemplate")
->with("value", "something")
->render();
});
in your javascript:
$.get(
"test",
function (data) {
$("#my-content-div").html(data);
}
);

After some digging some more I found this which helped me to solve the problem.
You have to use the .load("url/page/...") via jquery and then set a route in the routes.php file that displays a view with the data that needs to be loaded e.g.
Route::get('/url/page/...', function(){
return View::make('test');
});
This returns the necessary php code which needed to be loaded dynamically, cheers.

How to handle multiple AJAX behaviors in one HTTP request?

I am using jQuery. I have implemented a multipart web page where a list of links* are rendered and each link is periodically updated through AJAX HTTP requests. That is, on the page there are many links of which each one is "timer-triggered" through JavaScript so to perform a HTTP request to the URL pointed by the link itself and, on response success, to replace those links with the retrieved data (the updated links).
This implementation works but it is "performance less" in cases when the page contains many links: one AJAX request is executed per link resulting in many hits to the server. In order to solve that performance issue I thought to make the JavaScript code to execute a unique AJAX request that retrieves the whole set of links and then to replace DOM data.
However I do not know how to implement the "unique request" mostly due to the practice/technique that I have to use and since it is the first time I notice this kind of problem. What can I do? Should I implement a JavaScript handler for event-registration or what?
* In my case link elements are used (<a></a> HTML tags) but those can be anything associated with a URL.
Update after the jfriend00 answer
If the solution is to build a JSON array as jfriend00 describes in his answer then I should implement the page behavior so to update the JSON array dynamically. Since my HTML links are even rendered dynamically along with some JavaScript code then that JavaScript code could update the JSON array dynamically by "registering"/"unregistering" links. If this is a solution in my case, how can I implement it?
I render links as "partial templates" along with the JavaScript code which JavaScript makes those links to execute AJAX requests. HTML-JS code per each link (the mentioned "partial templates") looks like the following:
<script type="text/javascript">
(function() {
var link = $('#link_1')
...
}());
</script>

It seems like you can just send some JSON that is your array of links to request and then receive JSON back that is an object where each key is the requested link and the data is the server response for that particular link.
If the links you want to process look something like this:
<a class="myLink" href="xxx"></a>
It could look something like this:
function processLinks()
// assuming you can specify some CSS selector to select the links in your page that
// you want to target
// create an array of URLs for the ajax call
// and an index of arrays --> DOM objects so we know which DOM object goes
// with a given URL when processing the ajax results
var urlArray = [];
var urlIndex = {};
var urlArray = $(".templateLink").each(function() {
urlArray.push(this.href);
urlIndex[this.href] = this;
});
$.ajax({
url: "your ajax url here",
data: JSON.stringify(urlArray),
dataType: "json"
}).done(function(data) {
// assumes you get data back as {"url1": data1, "url2": data2, ...}
$.each(data, function(url, urlData) {
// get DOM object that goes with this URL
var domObj = urlIndex[url];
// apply urlData to domObj here
})
});
}
Updating my answer now that you've disclosed your "partial templates".
To process them all at once, change this type of structure which processes them one at a time:
<script>
(function() {
var link = $('#link_1')
...
}());
</script>
<a href="yyy" id="link_2></a>
<script>
(function() {
var link = $('#link_2')
...
}());
</script>
to this which finds them all in the DOM and process them all at once:
<script>
// process all the template links
$(document).ready(processLinks);
</script>

Refresh Part of Page (div)

I have a basic html file which is attached to a java program. This java program updates the contents of part of the HTML file whenever the page is refreshed. I want to refresh only that part of the page after each interval of time. I can place the part I would like to refresh in a div, but I am not sure how to refresh only the contents of the div. Any help would be appreciated. Thank you.

Use Ajax for this.
Build a function that will fetch the current page via ajax, but not the whole page, just the div in question from the server. The data will then (again via jQuery) be put inside the same div in question and replace old content with new one.
Relevant function:
http://api.jquery.com/load/
e.g.
$('#thisdiv').load(document.URL + ' #thisdiv');
Note, load automatically replaces content. Be sure to include a space before the id selector.

Let's assume that you have 2 divs inside of your html file.
<div id="div1">some text</div>
<div id="div2">some other text</div>
The java program itself can't update the content of the html file because the html is related to the client, meanwhile java is related to the back-end.
You can, however, communicate between the server (the back-end) and the client.
What we're talking about is AJAX, which you achieve using JavaScript, I recommend using jQuery which is a common JavaScript library.
Let's assume you want to refresh the page every constant interval, then you can use the interval function to repeat the same action every x time.
setInterval(function()
{
alert("hi");
}, 30000);
You could also do it like this:
setTimeout(foo, 30000);
Whereea foo is a function.
Instead of the alert("hi") you can perform the AJAX request, which sends a request to the server and receives some information (for example the new text) which you can use to load into the div.
A classic AJAX looks like this:
var fetch = true;
var url = 'someurl.java';
$.ajax(
{
// Post the variable fetch to url.
type : 'post',
url : url,
dataType : 'json', // expected returned data format.
data :
{
'fetch' : fetch // You might want to indicate what you're requesting.
},
success : function(data)
{
// This happens AFTER the backend has returned an JSON array (or other object type)
var res1, res2;
for(var i = 0; i < data.length; i++)
{
// Parse through the JSON array which was returned.
// A proper error handling should be added here (check if
// everything went successful or not)
res1 = data[i].res1;
res2 = data[i].res2;
// Do something with the returned data
$('#div1').html(res1);
}
},
complete : function(data)
{
// do something, not critical.
}
});
Wherea the backend is able to receive POST'ed data and is able to return a data object of information, for example (and very preferrable) JSON, there are many tutorials out there with how to do so, GSON from Google is something that I used a while back, you could take a look into it.
I'm not professional with Java POST receiving and JSON returning of that sort so I'm not going to give you an example with that but I hope this is a decent start.

You need to do that on the client side for instance with jQuery.
Let's say you want to retrieve HTML into div with ID mydiv:
<h1>My page</h1>
<div id="mydiv">
<h2>This div is updated</h2>
</div>
You can update this part of the page with jQuery as follows:
$.get('/api/mydiv', function(data) {
$('#mydiv').html(data);
});
In the server-side you need to implement handler for requests coming to /api/mydiv and return the fragment of HTML that goes inside mydiv.
See this Fiddle I made for you for a fun example using jQuery get with JSON response data: http://jsfiddle.net/t35F9/1/

Usefetch and innerHTML to load div content
let url="https://server.test-cors.org/server?id=2934825&enable=true&status=200&credentials=false&methods=GET"
async function refresh() {
btn.disabled = true;
dynamicPart.innerHTML = "Loading..."
dynamicPart.innerHTML = await(await fetch(url)).text();
setTimeout(refresh,2000);
}
<div id="staticPart">
Here is static part of page
<button id="btn" onclick="refresh()">
Click here to start refreshing every 2s
</button>
</div>
<div id="dynamicPart">Dynamic part</div>

$.ajax(), $.get(), $.post(), $.load() functions of jQuery internally send XML HTTP request.
among these the load() is only dedicated for a particular DOM Element. See jQuery Ajax Doc. A details Q.A. on these are Here .

I use the following to update data from include files in my divs, this requires jQuery, but is by far the best way I have seen and does not mess with focus. Full working code:
Include jQuery in your code:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.6.0/jquery.min.js"></script>
Create the following function:
<script type="text/javascript">
function loadcontent() {
$("#test").load("test.html");
//add more lines / divs
}
</script>
Load the function after the page has loaded; and refresh:
<script type="text/javascript">
$( document ).ready(function() {
loadcontent();
});
setInterval("loadcontent();",120000);
</script>
The interval is in ms, 120000 = 2 minutes.
Use the ID you set in the function in your divs, these must be unique:
<div id="test"></div><br>