Iterating through FormData in IE

internet-explorer, javascript

Solution

There's a `FormData` polyfill that works. For details, read their docs.

IE 10, IE 11 and Edge

To make it work with IE 10 and above, you'll just have to add a `WeakMap` polyfill as well.

JSBin demo for IE10 and above.

<script src="https://unpkg.com/weakmap-polyfill/weakmap-polyfill.min.js"></script>
<script src="https://unpkg.com/formdata-polyfill"></script>

<form action="" id="f">
    <input type="text" name="i1" value="v1">
    <input type="text" name="i2" value="v2">
</form>

<script type="text/javascript">
    console.clear();

    // Create a test FormData object
    var formData = new FormData();
    formData.append('key1', 'value1');
    formData.append('key2', 'value2');

    // Display the key/value pairs
    var formDataEntries = formData.entries(), formDataEntry = formDataEntries.next(), pair;
    while (!formDataEntry.done) {
        pair = formDataEntry.value;
        console.log(pair[0] + ', ' + pair[1]);
        formDataEntry = formDataEntries.next();
    }

    // or, if you are really into compact code
    var es, e, pair;
    for (es = formData.entries(); !(e = es.next()).done && (pair = e.value);) {
        console.log(pair[0] + ', ' + pair[1]);
    }

    // testing getting from form
    var myForm = document.getElementById('f');
    for (es = new FormData(myForm).entries(); !(e = es.next()).done && (pair = e.value);) {
        console.log(pair[0] + ', ' + pair[1]);
    }
</script>

Code above picks up the latest versions. Versions tested: `https://unpkg.com/weakmap-polyfill@2.0.0/weakmap-polyfill.min.js` and `https://unpkg.com/formdata-polyfill@3.0.9/formdata.min.js`

IE11 and Edge, only (if you don't have to support IE10):

If you only need IE 11 and above, you can remove the `WeakMap`'s polyfill and just keep `FormData`'s.

JSBin demo here.

<script src="https://unpkg.com/formdata-polyfill"></script>

<form action="" id="f">
    <input type="text" name="i1" value="v1">
    <input type="text" name="i2" value="v2">
</form>

<script type="text/javascript">
    console.clear();

    // Create a test FormData object
    var formData = new FormData();
    formData.append('key1', 'value1');
    formData.append('key2', 'value2');

    // Display the key/value pairs
    var formDataEntries = formData.entries(), formDataEntry = formDataEntries.next(), pair;
    while (!formDataEntry.done) {
        pair = formDataEntry.value;
        console.log(pair[0] + ', ' + pair[1]);
        formDataEntry = formDataEntries.next();
    }

    // or, if you are really into compact code
    var es, e, pair;
    for (es = formData.entries(); !(e = es.next()).done && (pair = e.value);) {
        console.log(pair[0] + ', ' + pair[1]);
    }

    // testing getting from form element
    const myForm = document.getElementById('f');
    for (es = new FormData(myForm).entries(); !(e = es.next()).done && (pair = e.value);) {
        console.log(pair[0] + ', ' + pair[1]);
    }
</script>

Code above picks up the latest version. Version tested: `https://unpkg.com/formdata-polyfill@3.0.9/formdata.min.js`

Problem

Original source