Laravel, sending PDF from controller to JS variable - javascript

I'm trying to make a very barebones page that loads in two specific PDF documents and on page load would simply display one and then after a 60 second timelapse, would cycle over and show the other.
My issue, currently, is simply getting the PDFs into variables in the JS so that I can assign the time cycle to them.
How can I take the PDFs being sent from the controller and put them into JS variables in order to accomplish this properly?
public function getPDFDocs()
{
if(Storage::disk('test_docs')->exists('testFirstFile.pdf')){
$file1 = Storage::disk('test_docs')->get('testFirstFile.pdf');
}
if(Storage::disk('test_docs')->exists('testSecondFile.pdf')){
$file2 = Storage::disk('test_docs')->get('testSecondFile.pdf');
}
return view('test.index')
->with('firstFile', $file1)
->with('secondFile', $file2);
}
index.blade.php
#section('loadjs')
getPDFPages() {
let visible = [];
//visible.push ({pages here??})
}
#endsection

First of all, it seems you are getting the contents of file PDF, not their path. So it may not be efficient to transfer entire PDF data in your initial HTTP response.
Do this PDF files publicly accessible? If so; return their http url instead of pdfs' data.
After that; to inject a data from Laravel backend to JavaScript in a blade file; best approach is turn your data to json, send it to blade and write it as an HTML element's data- attribute, then in JavaScript read it from data- attribute and decode json to a JS object.
Here is an example;
public function getPDFDocs()
{
if(Storage::disk('test_docs')->exists('testFirstFile.pdf')){
// assuming this files publicly accessible and use url method
$files[1] = Storage::disk('test_docs')->url('testFirstFile.pdf');
}
if(Storage::disk('test_docs')->exists('testSecondFile.pdf')){
// assuming this files publicly accessible and use url method
$files[2] = Storage::disk('test_docs')->url('testSecondFile.pdf');
}
return view('test.index', ['files' => $files]);
}
In your blade;
<!-- write down your html here -->
<span id="filesdata" data-files="{{ json_encode($files) }}" ></span>
#section('loadjs')
var filesJson = document.getElementById('filesdata').getAttribute('data-files');
var files = JSON.parse(filesJson);
// now you have your files, lets check them
console.log(files);
getPDFPages() {
let visible = [];
//visible.push ({pages here??})
}
#endsection
And use PDF URLs to show them in client. Let the client request and get raw pdf data, don't try to return them in your initial response.

Related

How to use information sended by the controller in a JavaScript file using Spring Boot?

I'm using Spring Boot with the Thymeleaf template engine. I have a HTML called clients.html file in the templates folder and a JavaScript file called functions.js in the static folder. I want to send from the controller to the JavaScript file a List.
I have tried using this syntax in the JavaScript file:
let listaArticulos = /*[[${numeroArticulos}]]*/ [];
But I don't recive anything. I have tried using the script tag in the HTML and it worked, but I want to have the JS code in a separate file and not in a script tag with all my html code.
The controller where I send the information to the JS looks like this:
#GetMapping("/articulos")
public ModelAndView showHielo(#RequestParam(name = "numcli", required = false) String numcli){
ModelAndView mav = new ModelAndView(ViewConstant.ARTICULOS);
mav.addObject("numeroArticulos", searchMovimNumarts(" 133"));
return mav;
}
Where the controller send the searchMovimNumarts() method with the name of "numeroArticulos" the one returns a List.
And the JS file where I want to recive the "numeroArticulos" object looks like this:
/*This variable stores data sended by the controller*/
let listaArticulos = /*[[${numeroArticulos}]]*/ [];
console.log(listaArticulos);
I want to console log the content of the List using a JS file and no the html
tag. How can I solve this?
Thymeleaf template engine parses only the template file(html files). So you have to include those variables defined in the controller into the embedded js code. However You don't have to put your entire js code in your html. Have only that part of code that refer to those variables in script tag.
<script>
let listaArticulos = /*[[${numeroArticulos}]]*/ [];
</script>
and refer them in your external js after this
<script src="/js/externalscript.js"></script>

How you can save appends to variables an then convert them to php so you can save them in a database?

<html>
<head>
<meta charset="utf-8">
<title>Test page for Query YQL</title>
<link rel="stylesheet" href="http://hail2u.github.io/css/natural.css">
<!--[if lt IE 9]><script src="http://hail2u.github.io/js/html5shiv.min.js"></script><![endif]-->
</head>
<body>
<h1>Test page for Query YQL</h1>
<div id="content"></div>
<input type="button" name="bt1" value="click" onclick="pesquisa()">
<form name="s2">
<input type="text" name="s1">
</form>
<script src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script src="jquery.query-yql.min.js"></script>
<script type="text/javascript">
function pesquisa(){
$(function () {
var t = $('#content').empty();
var url= document.s2.s1.value;
var statement = 'select * from feed where url="'+url+'"';
$.queryYQL(statement, function (data) {
$('<h2/>').text('Test: select * from feed').appendTo(t);
var r = data.query.results;
var ul = $('<ul/>');
$.each(r.item, function () {
$('<li/>').append(this.title).appendTo(ul);
$('<li/>').append(this.link).appendTo(ul);
<?php
$titulo = "<script>document.write(titulo);</script>";
$site = "<script>document.write(site);</script>";
//echo $titulo;
//echo $site;
?>
});
ul.appendTo(t);
});
});
};
</script>
</body>
</html>
How can you save the this.title and the this.link values into 2 different variables an then call them into php so you can insert the data into a DB?
It's just a simple YQL query to search on rss feeds.
After doing the query, I want the results to be saved in a database, but I can't discover how to do that.
First of all, you have to understand that you are working on a Client-Server architecture.
This means:
Let's say that this file you are showing us is called "TestYQL.php" (because you did not say the name of it). This file is executed by php (server side), which reads line by line the contents of it, and generates another new file from the original. For educational purposes, let's say the generated file is called "GeneratedTestYQL.html". This file no longer has any php code inside, since it is directly html and js flat. It knows nothing about php. So there are no php functions, variables, nothing. This last file is the one that reaches the client, and the code is executed by a web browser like Chrome, Firefox, etc.
In your case, the file "TestYQL.php" all you have of php is what is inside the <? Php ....?> Tags. With php you creates 2 variables, each with a tag inside, but without any purpose since they are not used in any way. So, the generated "GeneratedTestYQL.html" file is the same as the original, but without the lines inside the <? Php ...?>.
This means that: The contents of the variables that you use in PHP can be sent to the browser, because with PHP you will generate the file that will be executed in the browser.
Now, when the file "GeneratedTestYQL.html" arrives, the browser starts to show all the contents of the file, it generates the form in which, when you click the button, executes the function pesquisa() and now starts javascript (JQuery) bringing data of the feeds, and for the first time, these variables "this.title" and "this.link" begin to exist in javascript.
Since there is no such thing as php here, you can NOT access those variables from php.
So, how to save that data in a DB?, well, the common way is to send all the data you want from the browser, to the server, then the server sees what to do with that data. To send data from the browser to the server, you do it by making GET or POST requests to a php file from the server (preferably another file, let's say it will be called "saveFeeds.php").
Data can be sent with a GET request, but it is semantically incorrect since GET means you want to fetch data from the server. So to send that data to the server, you will have to make a POST request from the browser, which is more appropriate.
There are now 2 simple ways to make a POST request. The first and most common of these is from a form in the browser, the other way is using Ajax.
How to do it from a form?
Currently in your code, you have already put a form (That is called "s2"), although currently the same is not necessary, but leave that now.
If you wanted to send the data through a form, you should do 2 things. First and most obvious, create the form; second, the data received from the internet (title and link of feed), send them to the server.
Assuming you fetch data from a single feed per url, and the designated file in charge of receiving the request will be "saveFeeds.php". So, you could create a form like the following after the previous one:
<Form class = "sender" action = "saveFeeds.php" method = "post">
  <Input type = "hidden" name = "title" value = ""> <br>
  <Input type = "hidden" name = "link" value = ""> <br>
  <Input type = "submit">
</ Form>
Then you need to put the feed data inside the form, because, at this moment, you can't send anything. You could add a function like:
Function appendFeedToForm (title, link) {
  Var form = $ (". Sender");
  Form.title.value = title;
  Form.link.value = value;
}
And then call it from inside the $ .each of the result as
AppendFeedToForm(this.title, this.link);
The second case, the easiest way to make a request to the same file using Ajax is with a JQuery shortcut:
$.post("saveFeeds.php", r.item);
If you are interested in validations, you can take a look at the JQuery documentation. The important thing about ajax requests is that you can send all the data you want without having to force you to reload the page. Therefore, you can send as many feeds as you want in the same way you would send one.
Now with the data sent from the client to the server, it is necessary to handle the reception of the data. Currently we were pointing all the data to the file "saveFeeds.php", so, now, finally we can put the content from javascript. To access them, simply in that file, you should check the fields:
$ _POST ['title'] // This names are from input names of form
$ _POST ['link'] // or properties sended through Ajax
So, here, you have tp prepare the connection to your database and save those parameters. Currently you did not mention which database engine you are using, so, for this moment, I'll shorten the answer here.
Note: I was not giving you the best practices to solve your problem, but rather the minimum necessary.

How to send data between to JS files?

I have two JS files.
First file contains a function obtains some data (particularly, my function gets state of AbstractJavaScriptComponent which is just a String, but I think it's not important).
And I want to send this data to another JS file (or make it accessible in that file in any way).
com_company_htmlcontent_web_screens_JsData = function() {
// this value is what I want to send
document.getElementById('myButton').value = this.getState().xhtml();
this.onStateChange = function() {
e.innerHTML = this.getState().xhtml();
alert("on State changed is called"); // but this inner function is not called
}
}
Are there any ways to make it possible?
Can you just send it with GET? Just pass the thata in URL that will switch you to the other file with js in it, then grab the data from it.
I don't really see the point of that action tbh. Can you state, what you want to archive?
If you just want to run some script that doing something with data given, and you dont want to change files you can send this data with Ajax.

Sending JSON and HTML page together in node.js

I am sending my HTML file to the client in node.js as shown below
app.get('/get', function(req, res) {
res.render(index.html);
});
Here, index.html refers to a json file.
How can I send both together or refer the json file in the client?
If you don't want to request the JSON file from the client as an independent HTTP request you can do one of the following:
Full server side rendering:
Use a template technology like moustache or handlebars, and try to render that data inline with the response. For example if you your JSON file returns a name and an address the index.html could look like:
<div>
<span>Name: {{name}} </span>
<address>Address: {{address}} </span>
<div>
Then when rendering you could pass a js object with properties name and address to the template and you wouldn't need to ask for the JSON file separately. This example follows moustache guidelines just in case I wasn't explicit enough.
Inline object
A bit like the previous solution but less elegant, you can add the full JSON response as an object with within a script tag, and then use it however you see fit. Try to append a block to he HEAD of index.html like this:
<script>
var myObject = <contents of your JSON object>
</script>
The other possible solution was just described in another answer.
I hope this helps.
HTTP only sends one resource at a time. If your page is requesting a JSON file, it needs to be served as a second request.
Alternatively, you can render HTML with a <script> block that has a variable assignment with your JSON-encoded data as a value.
You can't send two types of files back in a single request, but you could either do an ajax call in the html to get the json you need:
<script type="text/javascript">
var json_data;
$.getJSON("URL_HERE", function(data) { json_data = data; });
</script>
or add the json to the html as a javascript object via a template engine (jade shown below):
script(type="text/javascript").
var json_data = #{ JSON.stringify(JSON_OBJECT_HERE) }

How can one incorporate JSON data with the returned HTML on the first request to the home page?

My scenario is this - the user asks for the home page and then the javascript code of the page executes an ajax GET request to the same server to get some object.
The server keeps the home page as a jade template.
So, right now it takes two roundtrips to load the home page:
GET the home page
GET the JSON object
I am OK with it, but just out of curiosity - what are my options to incorporate the object requested later into the initial GET request of the home page?
I see one way is to have a hidden html element, which inner HTML would be the string representation of the object. A bit awkward, but pretty simple on the server side, given that the home page jade template is preprocessed anyway.
What are my other options?
Please, note that I am perfectly aware that sparing this one roundtrip does not really matter. I am just curious about the techniques.
Another option is to always return a JSON object, then the HTML for your home page would be the value of some property on this object. This would probably require some changes on your client-side logic, though.
One more option: instead of a hidden HTML input/textarea containing a JSON string, the home page code could contain a script block where an object literal is declared as a variable. Something like this:
<script>
var myObj = ... // Your JSON string here.
// myObj will be an object literal, and you won't need
// to parse the JSON.
</script>
The initial GET request will retrieve just that document. You can have additional documents loaded defined as scripts at the bottom of your page, so you don't need to do a XHR, for the initial load.
For instance:
GET /index.html
//At the bottom you have a <script src="/somedata.js"></script>
GET /somedata.js
//here you define you var myObj = {}.... as suggested by bfavertto
Depending on which server side technology are you using, this could be for instance in MVC3
public partial class SomeDataController : BaseController
{
public virtual ContentResult SomeData()
{
var someObject = //GET the JSON
return Content("var myObj = " + someObject, "application/javascript");
}
}
You can embed the Json data inside a hidden tag in your HTML. At runtime, your javascript reads the data from this hidden tag instead of making a Json call (or make the call if this data is not available).
<!--the contents of this div will be filled at server side with a Json string-->
<div id="my-json-data" style="display:hidden">[...json data...]</div>
on document ready:
var jsonStr = document.getElementById( "my-json-data" ).innerHTML;

Categories

Resources