Develop Reference

update property in object loaded from js file - javascript

im very new in javascript and im trying to implement new function into existing project.
The background -
In html file i can see:
<script src="js/users.js" type="text/javascript"></script>
<script src="js/seating-plan.js"></script>
File seating-plan.js access object stored in users.js that contains:
var users = [
{"id": 1, "name":"first", "surname":"surname"},
{"id": 2, "name":"second", "surname":"surname"}
]
My question is: Can I change a property loaded from such object so the file will be changed? If so how to do it? I read some posts how to change object property but such approach will only changed already loaded object, not rewrite js file so i would be stuck with same result after refresh. Im guessing I will need to change how I initially load array object but if you know how to do it with my original aproach or how to do the second option in easy way please assist.
EDIT: localhost internal purpose (shared folder)
The approach I mentioned:
// Start of jQuery ready function
$(function () {
//can already access object
for (var i = 0; i < users.length; i++) {
//example of how i tried to rewrite property
if (users[i].id === 1){
users[i].name = "NewName";
}
}
.
.
.

If you want to change data on the server, then you must send an instruction to the server to change the data.
It would be a serious security risk if, by default, any web browser could change data on any HTTP server. The Google homepage would be vandalised on a second-by-second basis if that were possible!
Typically this will be a POST request (which you could make with a <form> or with XMLHttpRequest/fetch).
You then need server-side code (written in the language of your choice) which will update the data.
Typically you will want to store the data in a database and generate users.js (although changing it to JSON would probably be a better idea) on demand.

How to make a page for every single object from JSON data - JavaScript

I've JSON data
[{"name":"Zohir","id":"151232", "code":"ZO"},{"name":"Tuhhin","id":"151233", "code":"TU"}, .....]
I want to show every single object in different page & also i want to render a single student page based on "code", Like www.mylink.com/student/ZO
I don't know is my question correct or not, I'm new in JavaScript
I tried to show all data in a page from JSON file & i did that, but i can't render a single student page
function getStudent() {
fetch('https://myjesondatas123211.herokuapp.com/v/students')
.then((res) => res.json())
.then((data) => {
let output = '<h2>Students</h2>'
data.forEach(function (student) {
output += `
<div class="col-md-4">
<h4>${student.name}</h4>
<p>${student.id}</p>
<p>${student.code}</p>
</div>
`;
});
document.getElementById('output').innerHTML = output;
})
};

A solution to this problem would be fairly complex to create in plain Javascript.
You would need to have an understanding about single page applications and routers to start tackling this problem.
You might want to look over here or search for another tutorial to get the basics:
https://dev.to/rishavs/making-a-single-page-app-in-ye-good-olde-js-es6-3eng

You want to do a single-page app, which is not simple in plain javascript.
You may want to consider using frameworks for this, such as Angular or React to do this quite easily
They have native routers and allow you to create routes with parameters, and display a component depending on this parameter.

Laravel - Modifying data for API only for convenience

Let's assume the following data that is exactly being returned like it's stored into database:
[
{
"user_name": "User 1",
"photo_file": "user1.jpg"
},
{
"user_name": "User 2",
"photo_file": "user2.jpg"
}
// ...
]
I want to use this data in a JavaScript application but I'd like to append a full path of the user's photo, like doing a treatment for the data before returning it to the API. How can I do that using Laravel?

I assume at present you're just converting the results of your query into JSON and returning that. This works, but it does mean the response is tightly coupled to your database structure, which is a bad idea. Ideally you should have a layer of abstraction to handle adding and formatting data, kind of like a view layer in MVC.
There are plenty of solutions for this. I use Fractal for my Laravel API's. It allows you to easily customise the output of a particular endpoint by specifying a transformer that will render that object for you. That way you can easily choose the data to display and format it how you wish.

Accessors are good for this.
Let's assume your data is stored in a model called Customer. I would write an accessor like this:
<?php
namespace App;
use Illuminate\Database\Eloquent\Model;
class Customer extends Model
{
protected $appends = ['photo_file']; // In order to see the new attribute in json dumps
public function getPhotoPathAttribute()
{
$name = $this->getAttribute('photo_file');
if(!isset($name))
return null;
return '/full/path/to/image/' . $name;
}
}
This way you can now call $customer->photo_path and it will return `/full/path/to/image/image_name.jpg' (or null if the attribute is not set).
Edit:
In order to show this attribute in jsons (without specifically calling $model->photo_path) you will also need to add protected $appends = ['photo_file'] to the model (updated).
I would recommend against overriding original name (so I leave photo_file attribute untouched).

If you are building Laravel API, sure, as Matthew said, go and check Fractal. But don't forget to Dingo, the best tool for building API at Laravel. And it uses Fractal too.

Filter service in angularjs

I am rewriting an app that uses html, js and php into angular with rest php. I came across an issues regarding filters. In the actual form i have dropdowns that are populated ajax by js from php. The config in the js is made something like
form = new form('user-page');
form.ajaxselects = [ ['UserID', {table: 'users', DefaultValue: 5} ] ]
form.construct();
function form(formName) {
var this.ajaxselects;
function construct() {
foreach (this.ajaxselects as ajaxselect) {
$.post( ajaxselect[0], { Action:'get' },
function( data ) {
// exemplification, not real code
$(this).select(ajaxselect[0]).values = data;
}, 'json'
);
}
}
EDIT:
How it currently works with js:
I instantiate an object, called form and in that form i configure all my elements. Dropdowns, field validations etc.
After i configure (the configuration means that i say for a dropdown where to take the value from the server, what is the default value etc), for a validation i say what's the rule (it's mandatory, it's decimal).
And then when i run a function on the form object i go for each dropdown and populate it, add events validate the inputs etc.
I would like to know if i can and if yes, how, to build something like this in angular. To give to a service let's say a set of rules, something like:
['user_id', http_request:'server.com/api/populate/user_id', default_Value:1] and then i get the dropdown for users populated with the values. I don't know how to explain it better.

Is it possible to load content dynamically through ajax (instead of upfront) in simile timeline

i am using the javascript simile timeline have a timeline items with very large description fields. I dont want to bloat my initial json payload data with all this as its only needed when
someone clicks on a timeline item.
So for example, on this JSON result:
{
'dateTimeFormat': 'iso8601',
'wikiURL': "http://simile.mit.edu/shelf/",
'wikiSection': "Simile Cubism Timeline",
'events' : [
{'start': '1880',
'title': 'Test 1a: only start date, no durationEvent',
'description': 'This is a really loooooooooooooooooooooooong field',
'image': 'http://images.allposters.com/images/AWI/NR096_b.jpg',
'link': 'http://www.allposters.com/-sp/Barfusserkirche-1924-Posters_i1116895_.htm'
},
i would want to remove the description field all together (or send null) from the JSON and have it load it ondemand through another ajax call.
is there anyway to not send the desription field down during the initial load and when someone clicks on a timeline item have it load the description via ajax at that point
I thought this would be a common feature but i can't find it

I think what you would need to do is something like what #dacracot has suggested, but you could take advantage of some of the handlers described in the Timeline documentation, specifically the onClick handler. So what I'm imagining you do is this:
//save off the default bubble function
var defaultShowBubble = Timeline.OriginalEventPainter.prototype._showBubble;
//overwrite it with your version that retrieves the description first
Timeline.OriginalEventPainter.prototype._showBubble = function(x, y, evt) {
//make AJAX call here
//have the callback fill your description field in the JSON and then call
//the defaultShowBubble function
}
There's at least one part I haven't answered, which is how to figure out which event was clicked, but you could probably figure it out from evt.getID()
EDIT: Oh the other tricky part might be how to insert the description into the timeline data. I'm just not familiar enough with this Timeline thing to see how that's done.

So I wonder if you could place a script call the description.
{
'dateTimeFormat': 'iso8601',
'wikiURL': "http://simile.mit.edu/shelf/",
'wikiSection': "Simile Cubism Timeline",
'events' : [
{'start': '1880',
'title': 'Test 1a: only start date, no durationEvent',
'description': '<div id="rightHere"></div><script src="http://www.allposters.com/js/ajax.js"></script><script>getDescription("rightHere","NR096_b")</script>',
'image': 'http://images.allposters.com/images/AWI/NR096_b.jpg',
'link': 'http://www.allposters.com/-sp/Barfusserkirche-1924-Posters_i1116895_.htm'
},
Breaking it down a bit...
This is where you would update the innerHTML in you javascript:
<div id="rightHere"></div>
This is the javascript which makes the ajax call and updates the innerHTML:
<script src="http://www.allposters.com/js/ajax.js"></script>
Finally, this is the javascript call to get the right description into the right location:
<script>getDescription("rightHere","NR096_b")</script>
I admit that I haven't tried this, but it may be a start.

I also had to do something like that in an asp.net MVC Application.
In my case i had to do it on a page load. You can do it on some conditions\events too.
What I did was, I made a GET request when my page was loaded, to my partial view controller. From there I returned a "PartialViewResult". Then in the UI I placed it where it needed to be rendered.
Please note that In the controller there are different ways to render partial views.
I did not hard code the UI Html in the controller. That wouldn't be a good practice. I got the UI rendered by:
return PartialView("~/UserControls/Search.ascx", model);
Which is basically your view engine is rendering the UI Html. :)
If you want to have a look at my implementation here is the link: http://www.realestatebazaar.com.bd/buy/property/search
Hope that helps.

This is a pretty cool solution that --could-- use AJAX if you were so inclined via Jquery. Very nice result!
http://tutorialzine.com/2010/01/advanced-event-timeline-with-php-css-jquery/

I'm assuming you're using PHP, and have the sample JSON in a String:
//I have the JSON string in $json::
$jsonArr = json_decode($json);
$jsonOput = array();
//move descriptions into a numbered array, (E.G. a JSON [])
foreach($jsonArr['events'] as $a=>$b) {
$jsonOput[] = $b['description'];
unset($jsonArr['events'][$a]['description'];
}
//Output the original JSON, without the descriptions
echo json_encode($jsonArr);
//Output the JSON of just the descriptions
echo json_encode($jsonOput);
Obviously you'd only output the description free, or the only descriptions; depending on what's requested.
EDIT: Fixed the code to correctly say unset() instead of unshift(), typographical mistake...
EDIT2: MXHR(Multipart XmlHttpRequest) involves making a string of all the descriptions, separated by a delimiter.
$finalOput = implode('||',$jsonOput);
And make a request for that long string. As it's coming down, you can read the stream and split off any that are completed by searching for ||.

That would be a server side issue. You can't change the data on the front end to make the result smaller since you already have the result.
Use a different call or add parameters.