index.php
<form method="post" action="process.php" > Firstname: <input type="text" name="firstname" /> <br /> Lastname: <input type="text" name="lastname" /> <br /> Description: <textarea name="description" rows="10" cols="50" ></textarea> <br /> File Upload: <input type="file" name="upload" /><br /> preview: <img src="#" /> <br /> <hr /> <input type="submit" value="Submit" /> </form> <hr /> display result form server
<div id="output"></div> get formHTML element and add onsubmit event, and create formData, then call ajax function with arguments formHTML, formData and output display ("#output")
<script> /* submit form */ document.querySelector( "form" ).addEventListener( "submit", function (event) { event.preventDefault(); // return false var formHTML = event.target; // this console.log( formHTML ); // formHTML element // https://developer.mozilla.org/en-US/docs/Web/API/FormData/Using_FormData_Objects var formData = new FormData( formHTML ); console.log( formData ); // https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest // https://www.w3schools.com/xml/xml_http.asp // https://www.w3schools.com/js/js_ajax_http.asp /* AJAX request */ ajax( formHTML, formData, "#output" ); // ajax( form, data destination ) }); </script> ajax function
<script> function ajax( form, data, destination ) { if (window.XMLHttpRequest) { var xhr = new XMLHttpRequest(); /* code for modern browsers */ } else { var xhr = new ActiveXObject("Microsoft.XMLHTTP"); /* code for old IE browsers */ } xhr.open( form.method, form.action, true ); // ( "post", "process.php", true ) xhr.send( data ); xhr.onreadystatechange = function () { if ( this.readyState == 4 && this.status == 200 ) { document.querySelector( destination ).innerHTML = this.responseText; } }; } </script> add onchange event in input with file type, then display it with img tag
<script> /* preview image */ document.querySelector( "input[type='file']" ).addEventListener( "change", function () { var preview = document.querySelector( "img" ); var file = document.querySelector( "input[type='file']" ).files[0]; var reader = new FileReader(); reader.addEventListener( "load", function () { preview.height = 100; preview.title = file.name; preview.src = reader.result; }, false ); if (file) { reader.readAsDataURL(file); } console.log( reader ); } ); </script> process.php
$data = array( "post" => $_POST, "files" => $_FILES ); echo "<pre>"; var_dump($data); echo "</pre>"; Demo repl.it
Top comments (0)