Pages

Tuesday, July 10, 2012

Upload Image Without Refresh Page - Asynchronous Image File Upload Without Ajax

Through concept such as Ajax and scripting languages like PHP, we now have a much robust set tools with which to deal with imaging. Thorugh Ajax, we can dynamically load and display images without the rest of the page having to reload, which speeds up the process considerably. We also have more control over what the user sees while the screen or images load. Users are generally understanding of load times, provided that you let them know what is happening. Thorugh Ajax and a little PHP magic, we can help the user's experience be a seamless and enjoyable as possible.

The basic uploading, manipulating and dynamically displaing images using PHP and Ajax.

Uploading Images
I suppose it is neccessary to bring a little bad news to Ajax at this point, it is not possible to process a file upload through the XMLHtrtpRequest Object. The reason of this is that javascript has no access to your computer's file system. While this is somewhat disappointing, there are still ways to perform Ajax-like functionality for this wighout making use of the XMLHttpRequest Object. Clever developeres have discovered that you can use hidden iframes to post a form request, thereby allowing for a image upload wiothout refresh.

I am designing a website with ajax and php. My main target is doing everything without full page refresh. I have done everything completed. I solved it partially using IFRAME.

By setting the iframe's CSS display property to none, the element is persent on the page to be utilized by the upload form, but not visible to the end user. by assiging a name to the iframe tag, you can use the target attribute in the form tag to post the request to the hidden iframe. Once you have the iframe configured, you can perform any uploads you like, and then use Ajax to perform any extra functionality. Consider the following example, which will allow yout to upload an image to a folder of your specification. Consider the code, which will allow you to create application.

An Ajax-enabled file upload system that uses hidden iframes to hide the upload
Ads by Google

The code to create form, with a hidden iframe for processing

As you can see, you are using the same functionality and you will now use it to load the recently uploaded image into your

web page dynamically and without a screen refresh. The uploading function will still perform your form submission, but it is now coupled with a function called downloading, which will fire once the process_upload.php script has finished uploading the image (determined by the onload evernt). The doneuploading function takes ther parent frame of the hidden iframe and the fine name as arguments. It then users Ajax to dyanmically load the image the speicified element of ther parent frame.

Im trying to create a page for a picture framing site where users can upload images to see how they would look framed.

Uploading images can be broken down into the three following steps which will be looked at in turn:

* An HTML form with a browse button to allow the client to choose which file to upload
* A script to process the upload, validate the file, name it and place it in the file system
* Lastly a page to advise the client the upload was a success
* Is there a AJAX based solution or PHP based solution to check the filesize a user is trying to upload via a form.
* If the filesize exceeds more than 2 MB we want to give a message to the user that they need to upload a smaller file

No comments:

Post a Comment