Develop Reference

Workaround for Error 414 when opening file from PHP script

I have a PHP script that's outputting a CSV file and up until now I've been just using a link and passing parameters that are used to determine the output in the GET data. However recently the size of the data increased and now that code gets Error 414 - Request URI too Large. I tried using a hidden form to do it with POST but it just reloaded the page and didn't supply a prompt to download the file and all of the suggestions I've been able to find online about doing it with AJAX suggest using a link with GET data instead. Does anyone know a workaround that will have the browser still let the user easily download the data?
Presently I'm just setting the href attribute of a <a> tag.
$("#exportCSV").attr('href', "myscript.php/?data=" + exportData);
exportData has become too long for GET data but I want to maintain the behavior where if you click on a link that has say a CSV file being outputted the browser provides a download dialog for the user.

Upload/download/save image to a local server from a remote server using an Image URL and PHP?

I am building a Discussion Forum as part of a bigger application I am building, the forum is just 1 section of the Application.
For my TextArea fields when posting a new Topic or a Post Reply, I have decided that nothing is as good as the PageDown Markdown Library. It is the same one that StackOverflow uses on all their sites and it works better than many of it's competitors.
The way the library ships though, I am not happy with the default Insert Image functionality. You hit the button to insert an image and it allows you to enter a URL for an Image and then it inserts the proper MarkDown syntax to show the linked image.
This just won't cut it. I need the functionality that you see on StackOverflow! Very similar anyways.
I need it to show a Dialog when you click the Insert Image button, like it does now, but instead of just an input field for a Image URL, it will have 2 filed options...
Upload image from your computer
Insert an Image URL and it will then DOWNLOAD the image from that URL and insert it into the post just as if you had uploaded it from your computer. This is important to not confuse this step. IT should not simply insert the Image linking it to the original Image URL. Instead it will take that URL and download/upload the Image to the same server that the upload from computer option does and then it will insert the NEW Image URL pointing to the newly uploaded image!
Based on some simple HTML like below for a Dialog window with a filed for my Upload from Computer functionality, which I already have working. I need to come up with some JavaScript and PHP that will download/save a remote image to my upload folder on my server when a button is clicked using only the URL that will be inside the URL text input field.
So it will need to do a few things...
Fetch and save an image file to my uploads folder using PHP when the only thing that the PHP function will receive is a URL of the image which could be on the same server or most likely a remote server.
After successfully saving/uploading an image from the URL, the PHP function will return a JSON string with the status/error and if successful then it will also return the actual URL and filename of where the new image is saved on the local server. The JavaScript/AJAX script will receive this JSON response and insert the Markdown syntax for the image into the PageDown editor.
The PHP function will need to ensure that the URL that it is trying to save/download is a valid image file and not some malicious file! Also not simply just some file of the wrong filetype like a non-image file unless we are allowing the file type.
It will be part of a module installed on many dinosaur servers so it needs to work on as many servers as possible too!
From the web
From your computer
I would be greatful of any help, tips, code snippets or anything to help with this. At this stage I really just need to build a nie PHP function that will upload images from a remote URL and also ensure that the URL passed in is a real image file or even better that it is in the allowed file types array!
A couple years ago I had started this but have now lost it and I am starting over and don't remeber much about how I went about doing it then.

The easiest way to download a file from a remote server would be to use copy (http://php.net/manual/en/function.copy.php):
copy('http://someurl.com/image.png', '/var/www/uploads/image.png');
As this function returns a bool, it is easy to determine whether the operation was successful and create a JSON response.
To verify that the file is an actual image, there is unfortunately no way that is 100% sure. It is probably enough to check the mimetype though. You can use finfo for that (http://php.net/manual/en/function.finfo-file.php):
$finfo = finfo_open(FILEINFO_MIME_TYPE);
echo finfo_file($finfo, $filename);
finfo_close($finfo);
For a gif, this would return image/gif for example. You will have to hardcode a list of all mimetypes you want to allow.

load external webpage and add custom header and use the data from webpage

I want to load a external webpage on my own server and add my own header. Also i need to use the data from the external website like url and content (i need to search and find specific data, check if i got that data in my system and show my data in the header). The external webpage needs to be working (like the buttons for opening other pages, no new windows).
I know i can play with .NET to create software but i want to create a website that will do the trick. Can this be done? Php + iframe is to simple i think, that won't give me the data from external website and my server won't see changes in the external url (what i need).

If it's supposed to be client-side, then you can acquire the data necessary by using an Ajax request, parsing it in JavaScript and then just inserting it into an element. However you have to take into account that if the host doesn't support cross-origin resource sharing, then you won't be able to do it like this.
Ajax page source request: get full html source code of page through ajax request through javascript
Parsing elements from the source: http://ajaxian.com/archives/html-parser-in-javascript (not sure if useful)
Changing the element body:
// data --> the content you want to display in your element
document.getElementById('yourElement').innerHtml = data;
Other approach (server-side though) is to "act" like a browser by faking your user-agent to some browser's and then using cUrl for example to get the source. But you don't want to fake it, because that's not nice and you would feel bad..
Hope it gets you started!

Writing string content as PDF

I have already build functionality to generate pdf file for reports that user view.
So what it currently does is when user clicks to the print pdf button it
Get the html content of the div that needs to be printed
Send this content to the controller's method using jquery ajax method with POST
In the controller it wraps the content with html document strings like <html>, <body> etc. plus I add some styles there.
Then this html string is passed to one of the tools I am using that returns me pdf bytes for this string
Then its saves those bytes as pdf file in a folder and returns the path of this file.
Jquery then on success method opens up the window for this file's path.
This all is working fine.
The problem is
It does not immediately opens up the window as it does all the processing and then on success it opens the window
Plus I am wondering if I am doing this all correctly or doing some extra unnecessary steps, from this I mean is there any better way or short way to do this.
Something like after getting content of div make some changes to the string to directly show it in the new window as pdf content etc. to avoid server processing, is that possible?
Till now I have tried to show the content directly with data:application/pdf but that didn't work.
If that is not possible, I am thinking to avoid saving of pdf file but just show the view that will open up as pdf, may be by setting its content-type, is that possible?

What you did is the best approach. (All) browsers don't have the capability to convert html to pdf so you can't just order them to open a page as pdf. You must serve the pdf file from the server. For more control you can serve the file from a script at a specified url and add appropriate headers:
header('Content-type: application/pdf');
header('Content-Disposition: inline; filename="the.pdf"'); // second parameter is the name of the file
Content type means browser will try to open it with a program appropriate for this MIME type.
Content Disposition inline means that browser will try to open it in the browser.
As server is working just display "loading" image to the user. That way the user will know that something is happening and that he needs to wait.

Ajax/Javascript - File Download

Client (Request through XMLHttpRequest) -> Server.
Server [Builds CSV and prints it on the output stream of response] -> Client.
Now step 3 should be-> Client's browser should show a download dialogue (save, open and cancel). Since the content type is plain text from the server, and the content disposition is not set, can we create a file using javascript and prompt the user to download?
I know this question is slight stupid. But there is no other option. I have to do it this way.
Changing in the server side script will make it a one minute task. But I have to do it in the client side. The responseText property of the XMLHttpRequest object will be plain text and I have to show download prompt for the text file.
Is this possible?

Not that I'm aware of. But you could just use location.href (or a form, if POST data is needed) to request the server-side file. With the correct headers (Content-Disposition: attachment and I think there's another one) you can have the response be downloaded rather than displayed.
EDIT: Even better, use an iframe that's hidden. That way, you can still do a fancy "Loading, please wait" thing in the main page.

Theoretically it could be possible, by using Data URI's
<a download = "yourfile.csv" href="data:application/octet-stream;charset=YOURCHARSET;base64,BASE64allthedata">Generate</a>