Pre populate a file input - javascript

I'm working on a job board site which submits user applications to a third party site. The users have to provide following information while applying: name, contact details and resume. Since these fields are also available on user profile on the site, we want to pre populate the form fields, allowing users to change the information as they like.
Now, all other fields can be populated without an issue. However, file input field can't be populated due to security violations. Is there a work around possible using FILE API and BLOB objects?
What I'm planning to do is the following:
Create a blob object from file URL on server
Read the blob as an array buffer using FileReader.
Attach this file to file input field <- this is what I'm not able to figure out and need help with.
Also, if there is any alternate way to achieve this, please let me know. I'm using PHP and JavaScript to generate the form, so I can do the preprocessing in PHP.

Attach this file to file input field <- this is what I'm not able to figure out and need help with.
It is not possible to set a value at FileList object of <input type="file"> element.
You can create and append a File object to a FormData object and submit FormData using XMLHttpRequest()
var data = new FormData();
data.append("file", /* Blob | File */, "filename.ext")

Creating an answer just to give a little more insights into how I solved this issue, and why there was an issue in the first place.
Background: I've created a custom WordPress plugin for a client, which fetches the job applications from various sites, and displays them inline. We also allowed application submission, where the users could attach their resume, and the same was submitted to the original job posting. Since, a lot of users access the website on their mobile, they do not have the resume available on the same. In such a case, we wanted to offer them a facility to use a resume stored on their profile.
Potential Solution: The simplest way to do this would've been to fetch the file contents via ajax from user's profile, and attach it to the form before submission. However, for whatever reason, this didn't work.
Applied Solution: The solution that worked is pretty old school. Instead of submitting the application directly, we submitted it to an intermediate page, which fetched the file contents from user's profile, modified the form data and submitted via curl. This also saved the double data exchange on user's end (file download and re-upload).

Related

Saving input->values without embed php

Main problem is values written in input elementss disseapear after page reload (submit , refresh etc.)
I have a completed form ... /form element. Traditionally, I can insert a php line.
<input value="<?php if(isset($_POST['foo']))echo $_POST['foo'] ?>">
This solves the submit part. However, I feel that this is the worst solution, in my case. I have hundreds of input elements in my form. There are even some inputs to produce input tables. Number of input elements are so much that i became curious about finding a work around.
Is there a way to store input->values before the submit operation and inject them after page reload?
So that, the user can upload a file, file will be parsed by php core. And when the page reloaded both user originated inputs and file originated values are exist.
To simplify:
After "file submit & read & append file values to form", user shouldn't need to fill inputs that s/he already filled. I need an idea to achieve this, different then "inserting a php line to every single input element."
In such a situation I could recommend sending the file via AJAX and handling the response of that thereafter and then only injecting the values from the process and uploaded file when you get the response from the server.
Alternatively you could use localstorage or cookies to persist the information. However both local storage and cookies have a defined limit on what they can store. Cookie can only store 4KB in total which doesn't allow much.
Without uploading via AJAX, you could write a javascript function to find all inputs with jQuery/javascript and save their values in localstorage and on new page load to a check to see if there are any present and inject them back into the same inputs based on id/class/ etc with jQuery making sure to delete the localstorage values when done.

Save the client HTML content back to the Server as a HTML file

I want to create an HTML form on the Server. When the client completes the form and clicks submit, I want to be able to save HTML form and data in a single HTML file on the server.
The best suggestion I have seen is using JavaScript. Use a client side script that on click will save the document.InnerHTML to a var that can then be submitted back to the server.
Is this the best approach, or is there an easier way?
Even though I have no idea why you want to save the whole html code because I'm sure there will be parts that are the same for every user and you will be wasting memory, but ok.
So there are two ways to do this:
1. is javascript as you said
2. would be to put all the generated html code into a hidden form input (already on server side)
the first one seems more comprehensive and this is what I would do but the second one would also work for users with js disabled.
I wouldn't really recommend this way, because I'm still a huge fan of saving data in a database, but here's a general outline of what to do:
User fills out the form and submits.
Server-side code executes a method:
a. String holding the template for your HTML page with placeholders for the fields.
b. Use String.Format to put all the user input into the correct places.
c. Create a file, write the string to the file, and save.
d. Return file name to user.
HTML files are not that large, but still you risk using up your hard drive space. Also, you need write permissions which introduces security risks.
Going the database route:
1. User fills out the form and submits.
2. Server-side code saves the data to a database, and returns a link (with querystring string of ID and possibly a user id to help with security) to the user.
3. Whenever the user goes to the link, the server-side code repopulates the form with the ID passed.

Processing a file upload with javascript before saving to database in Cakephp

I have a form that includes a file upload.
I need to extract some meta information using javascript from the file before saving the contents of the form to my database.
What would be the best way, if any, of achieving this?
To clarify: The issue isn't the with extracting the file meta but rather how to access the $_FILES array and execute a js file with this data before finally allowing the form to submit to the server.
How I am achieving this currently:
I submit the form to the controller action
It saves the data and then it sets a view variable with the location of
the uploaded file before re-rendering the initial view upon successful form submission
The view checks if the variable is set, and if it is, executes the
javascript which basically extracts the meta now that it can access where the file is, and updates the db
with an ajax call.
The above method is not ideal in that the meta belongs to the same row of data that is saved when the form first submits so ideally I would like to include it initial form submission and not when the page is rendered again after the form has been submitted. Seems like a bit of a dirty hack to me but I can't as of yet see another way this can be achieved.
I would suggest uploading using ajax (SWFUpload/Uploadify) and then sending data back to the view with the processed file data.
You can upload the file, issue a number of callbacks, and finally return the rendered filedata back to the waiting javascript function that issued the request.
Just my two cents
What sort of metadata? To answer your question, yes, this is possible, but only if the browser supports the File API. This excludes IE9 and older. For more information, see this MDN article on FileReader. There are various libraries that will extract specific types of metadata from files. For example, if you are interested in parsing EXIF metadata from an image file, you should look into something like jQuery-fileExif.

page navigation without losing form field data?

I would like to know instead of using PHP Sessions to save the field data, is there any concept in Ajax or jQuery, to navigate between lot of form pages, but to save the form data until the user submits, if user submits, all the information present on different pages should also get submitted.
you can try the form wizard its a jquery plugin : http://www.jankoatwarpspeed.com/post/2009/09/28/webform-wizard-jquery.aspx
There are multiple concepts of that type.
You can use JavaScript with the jQuery library to paginate a huge form using functions for HTML elements manipulation. That way, you don't require the user to create another HTTP request, and thus the information entered on other pages doesn't get lost when the user switches pages. The form can then be submitted using AJAX or a normal, "front-end" HTTP request method.
Also, you could try saving the entered information in a cookie with JavaScript and jQuery.
Here are some examples of jQuery pagination:
http://dl.dropbox.com/u/4151695/html/pajinate/examples/example1.html.
You can easily apply these concepts with anything, including HTML forms.
And here are various plugins with source:
http://www.jquery4u.com/plugins/10-jquery-pagination-plugins/.
A cookie is nothing more than a plain text file that is stored on a visitor's computer, which means you can easily encode and embed your form data into it.

File Input filling with data from URL

At a form, I have a file input field (for image) and I want to add an optional way to fill this field by fetching data via ajax API and this returns me the URL of an image.
How can I set the content of the field input as the URL image, especially is it possible without passing a hidden a hidden text field to pass this image URL to the server?
File inputs are for uploading the content of files from the client to the server. Since browsers won't let you (as a page author) download a file on behalf of the client, this isn't possible.
If what you were asking was possible, I could make you download a multi-gigabyte file just by making you visit my webpage. That wouldn't be a good situation to be in.
If you don't want the user to download and re-upload a file, then you don't want a file input. The other solution you mentioned (a field just containing the URL) sounds perfect for this.

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