How can I send multiple images created by PHP directly to JS? - javascript

I have a PHP script that generates images. At this moment with every request PHP creates a temporary directory and fills it with the created images, then it sends the links to JS, which displays them in the browser in a special order.
Is there any way to pass these images directly from PHP to JS without a temporary directory?
I don't want to use temporary directories because it takes space and resources of server and I have to check that images download has been completed before deleting them.
I am thinking on using Json encoding and decoding but I don't like this because it's time consuming.
Is there another way to send images directly from PHP to JS?
There is a way to work with using src to php script with headers:
Using PHP to send a certain image
or
How to generate image file using this PHP function?
But this I could only work with one image per request.
I mean - if I have 5 or 6 divs with images I have to make 5 or 6 requests from JS to my php script.
Is there a way to send multiple images from PHP to JS?

My first idea would be to encode those images with base64_encode and pass that encoded data to your JavaScript. With this approach, you don't have to save those images anywhere.
More information on displaying base64 encoded images: Base64 Encoding Image

What you can do to not overload your server is to use an image hosting external website, like imgur, giphy, etc. This will scale the image for you in different size, see their api.
Here I am going to share a little hack, to host permanently contents into the internet archive. it is easy to implement from php.
Please don't use it for high traffic.
1/ Host your content on your site, create a url_link.
2/ Post your link to archive.org:
https://web.archive.org/save/*url_link*
3/ Response is a link on the form:
https://web.archive.org/web/20180XXXXXX626if_/*url_link*
4/ Modify the link, remove if_ this is the permanent link for the next centuries.
https://web.archive.org/web/20180XXXXXX626/*url_link*
5/ Delete content from your server

Related

Is it possible to run a PHP file with HTML on the server

Normally when you have a .PHP file and the client request it, the PHP code is run on the server and the HTML and JavaScript are sent to the client.
Question
Is it possible to have the server request a webpage (local) and run both the PHP code and the HTML with JavaScript on the server? I have created a single .html file that after 3 seconds of processing locally creates the image data for a thumbnail of the given video.
Why
I need to generate a thumbnail for a video. I used shared hosting and my hosting provider doesn't support for ffmpeg. You can, however, generate thumbnails using a canvas and JavaScript. I have already put a lot of pressure on the client. If this is possible, upload and download times would be significantly shorter than using the client.
Attempts
I've tried using file_get_contents(), but it doesn't run the code (Makes sense). Is there a way I could have it open and run for x seconds and then grab the contents?
I've tried using curl to get the file using this function here. I believe it is similar to my previous attempt in that it gets the file contents, but never executes them.
My final attempt was to use new DOMDocument(). I couldn't even get to loading the page though. First, I can't parse it with a video tag. It gives this error:
Warning: DOMDocument::load(): Specification mandates value for attribute controls in
file:\path\to\html\document.html, line: 53 in C:\path\to\php\document.php on line 50
If I were to remove the video tag (which is required), I get errors while parsing my JavaScript. So that attempt also did not work.
Is there a way that I could have PHP process the code (for something on the server) for x seconds before getting the contents? It would allow for time to generate the thumbnail data. If there is another way to do this without using ffmpeg on the server, that would be great.
So as I mentioned in comments, what I'm gonna explain is just an option (not the best one and just answering for your need of running html code!)
Where to do this?
Personally I rather to do this when the video is being uploaded by admin's browser and the best thing is that you can do this as a part of the posting procedure.
So in the page that you want this process to be done, put an invisible iframe like this.
<iframe id="myIframe" style="display: none;"></iframe>
How to begin the process?
I don't know the way you use to upload the videos (and it really is not that important!) but let's assume you want to use formdata. After the video is uploaded you need to know something unique to address the video (let's say an id). So after the video is uploaded, we can recive a code like id:20, initiateThumbnail:true as the result json data. Then we can simply use that hidden iframe to be the browser you've been asking for like this:
$("#myIframe").attr("src","dothething.php?video=20");
Now do what ever you wanted to do in it and change it's content after it's done. Now you need to wait for the result!
$('#myIframe').load(()=>{
let result = $("#myIframe").contents();
// checking result!
});
As you have already thought about, you can handle any errors by processing the result.
Notes
The event listener we used for iframe (iframe.load) fires when you initiate making the thumbnail as well. So be careful with the process of checking result (content of that iframe!)
If you don't use ajax or formdata, simply the action of your form is what I used as iframe.
One question? What happens if network connection goes down during this process? Simple answer! You can check in so many ways that the thumbnail exists or not. If not you can create it once that user requests for it in his browser and upload it back to server and save it for ever (as you did it in admin's panel!)
I think there isn’t another way to generate thumbnail on php server than with ffmpeg.
The only thing you can do, I suppose, is to force canvas generation on page load if you aren’t already doing it.
Anyway you are trying to do something wrong. Php doesn’t evaluate the html code, it’s just a preprocessor and not an interpreter like the browser. You can wait all the time of the world, but you’ll never get the content of the image that only a browser will generate.

Saving user uploaded image to folder and/or server

I have an app, that allows users to upload an image, crop it and with other data save it all as html file to be used as a footer for emails. The image is given to them as base64.
Howver turns out this is not supported by Outlook, since it doesnt accept b64 data as img source.
So my idea was to save the cropped image to a file, let's say /public/avatars/avatar.png and link it's directory as a source. However I'm having trouble finding a way how to save images to to a file using JS. My allowed stack is JS and React, no node.js.
How would I do that? I can have the file as either b64 ot canvas element, so i'm flexible here, as long as it's saved to file.
I'm open to other solutions too.
You can't save a file with client language only. You have to save it to a server, own server or external server or a service like AWS.
The best solution without server-side (strangly) is to use a API for save image and get link from this API. Then you can use this link to Outlook.
You can use https://aws.amazon.com/fr/cloudfront/ free for one year with 50Go and 2 millon request monthly.
If you do not exceed 300,000 images per year you can use this service : https://cloudinary.com/pricing
You can also use https://www.deviantart.com/developers/ but that's not really the point of service.
Weird solution :
Be careful, the login and password of your FTP user will be available in the source of your code. Minimum rights must be administered.
You can use this script for talk to FTP server from JS (not tested but seems worked) : http://www.petertorpey.com/files/ae/scripts/FTPConnection.jsx
You can try something like that :
var ftp = new FtpConnection("ftp://URL") ;
ftp.login("username", "password");
ftp.cd("FOLDER") // For move to folder
ftp.put(file,"FILE.PNG") ; // File must be a File JS Object
ftp.close() ;

How to convert html to base64 and save an image on a server with php?

I have a json file like this:
{"user":{"email":"user#test.com"},
"screenshot":{"blobFile":"<!DOCTYPE html><html lang=\"en\">...</html>"}}
and I want to take a screenshot, using XMLHttpRequest sending data a PHP file.
In PHP file getting request like:
$data = json_decode(file_get_contents("php://input"), true);
$htmlStr = json_encode($data["screenshot"]["blobFile"]); // <!DOCTYPE html><html lang=\"en\">...
so far everything is ok but how to convert this string to the image file and save a server?
I've tried html2canvas in PHP file but not fire.
any ideas?
I'd try to use PhantomJS. It's headless browser, which allows to interact with web pages many ways including making screenshots. It will require some time to understand how to work with it, but it definitely will get a result. Although, PhantomJS sometimes is a headache if your page is quite complicated structured, written using some frameworks like ReactJS, AngularJS, etc.
What it does it renders HTML page with styles including scripts serverside. If you save not HTML string but exact URL with COOKIE and SESSION data and then reconstruct conditions which user had in an opened page when you did a screenshot, it'll do a job.
See example here Screen Capture on PhantomJS

how to secure img src path when user clicks on view source using javascript?

How to secure the src path of the image when clicks on inspect element so that user should not get to know about the actual src path..please help me with the solution and it should be done with javascript only no other tags should be used.
You can convert image into base 64 data URIs for embedding images.
Use: http://websemantics.co.uk/online_tools/image_to_data_uri_convertor/
Code sample:
.sprite {
background-image:url(data:image/png;base64,iVBORw0KGgoAAAA... etc );
}
This is commonly done server-side, where you have an endpoint that serves the image file to you as bytes...
You can store the images in a private location on the server where IIS/<your favourite web server> doesn't have direct access to it, but only a web app, running on it, with the required privilege is authorized to do so.
Alternatively people also "store" the images in the database itself and load it directly from there.
In either case, the response which has to be sent back has to be a stream of bytes with the correct mime type.
Edit:
Here are a couple of links to get you started if you are into ASP.NET:
http://www.codeproject.com/Articles/34084/Generic-Image-Handler-Using-IHttpHandler
http://aspalliance.com/1322_Displaying_Images_in_ASPNET_Using_HttpHandlers.5 <- this sample actually does it from a database.
Don't let the choice of front-end framework (asp.net, php, django, etc) hinder you. Search for similar techniques in your framework of choice.
Edit:
Another way if you think html5 canvas is shown here: http://www.html5canvastutorials.com/tutorials/html5-canvas-images/
However you run into the same problem. Someone can view the image url if they can see the page source. You'll have to revert to the above approach eventually.

Random image upon refresh with only one single image URL

Tried googling for a readily available script, but to no avail. I'm trying to find a script that does the below. Im not sure of there is a name for it.
Thank you in advance!
Function: Banner rotator with a single URL (PHP based)
Example:
User uploads 5 images (468x60px)
The system generates a a single image URL (e.g. http://demo.com/image.gif)
When user goes to the generated URL, it randomly shows 1 of his 5 images
Every time he refreshes the URL, it randomly shows him another one of his images
You can have the server-side code that processes the given URL return a random image each time. If you specify the server-side language (PHP, ASP.Net, JSP, ...) that you are using, I can give an example.
The URL can be something like
http://demo.com/image/
It does not need to have a specific image name in it.
The key is to ensure that the browser does not try and cache that URL. Set appropriate cache headers when returning the image. Again, the mechanics of doing that are specific to your language.
PHP Example
This short tutorial shows you now to select a random image from a folder of images
http://www.heckdesigns.com/tutorials/tutorial-pull-in-a-random-image-from-a-folder-with-php/
URL
You really should not have to require your URL to end in .png or whatever. If you set the Content-Type appropriately (as the tutorial above does), any web browser should display it properly. If that is in fact a requirement, you can use Apache rewrite rules to do that.
See
mod_rewrite and image redirecting

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