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js/checkPDF.js
/**
* Used to attach events to an element or object in a browser independent way
* @param element
* @param event
* @param callbackFunction
*/
function attachEvent(element, event, callbackFunction) {
if(element.addEventListener) {
element.addEventListener(event, callbackFunction, false);
}
else if(element.attachEvent) {
element.attachEvent('on' + event, callbackFunction);
}
}
/**
* Returns true if the HTML5 File API is supported by the browser
* @returns {*}
*/
function supportsFileAPI() {
return window.File && window.FileReader && window.FileList && window.Blob;
}
/**
* Method to be called upon changing the contents of a input element before uploading a file
* @param event
*/
function preUpload(event) {
// The file API supports the ability to reference multiple files in one <input> tag
var file = event.target.files[0];
console.log(file);
var reader = new FileReader();
attachEvent(reader, "load", (function(fileToCheck) {
return function (evt) {
var data = evt.target.result.substr(0, 8);
var regex = new RegExp("%PDF-1.[0-7]");
console.log(data);
if(data.match(regex)) {
alert(fileToCheck.name + " is a valid PDF File.");
}
}
})(file));
var MBSize = file.size / 1024 / 1024;
if(MBSize > 10) {
if(!confirm(file.name + " is " + MBSize + "MB big, and may cause your browser to stop responding while it parses it.\nContinue?")) {
return;
}
}
reader.readAsText(file);
}
function pageLoaded() {
var fileInput = document.getElementById("fileUpload");
if(supportsFileAPI()) {
attachEvent(fileInput, "change", preUpload);
}
else {
alert("Your browser does not support the HTML5 File API.");
}
}
attachEvent(window, "load", pageLoaded);
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