How to apply MDL button style to a filePicker? - material-design

Question

I would like to know if there is a way to apply the Material Design Lite button style to a file picker, i.e. a component created on an HTML page via:
<input type="file" id="filePicker" />
I would like the "Browse" button of the component to have the look of a Raised button (with ripple if possible). See http://www.getmdl.io/components/#buttons-section.
Thanks!

Answer 1

Using CSS, do you mean something like this?
<style>#file { display: none }</style>
<input type="file" id="file">
<label for="file" class="mdl-button mdl-js-button mdl-button--fab mdl-button--colored">
<i class="material-icons">+</i>
</label>
https://jsfiddle.net/sj838cLg/

Answer 2

Currently, there's no "official" way of doing that. According to the discussion on this issue, the reason is that there's no Material Design specification for that component, so they don't have a guideline to style it. On that same page, the user kybarg provided a CSS/JavaScript code to style a file picker which kind of matches the Material Design specification, so you can use that code:
HTML:
<form>
<div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label">
<input class="mdl-textfield__input" type="text" />
<label class="mdl-textfield__label">Name</label>
</div>
<div class="mdl-textfield mdl-js-textfield mdl-textfield--floating-label">
<input class="mdl-textfield__input" type="text"/>
<label class="mdl-textfield__label">Position</label>
</div>
<div class="mdl-textfield mdl-js-textfield mdl-textfield--file">
<input class="mdl-textfield__input" placeholder="File" type="text" id="uploadFile" readonly/>
<div class="mdl-button mdl-button--primary mdl-button--icon mdl-button--file">
<i class="material-icons">attach_file</i><input type="file" id="uploadBtn">
</div>
</div>
</form>
CSS:
html {
width: 100%;
}
body {
background: #f5f5f5;
margin: 50px auto;
width: 512px;
}
.mdl-button--file {
input {
cursor: pointer;
height: 100%;
right: 0;
opacity: 0;
position: absolute;
top: 0;
width: 300px;
z-index: 4;
}
}
.mdl-textfield--file {
.mdl-textfield__input {
box-sizing: border-box;
width: calc(100% - 32px);
}
.mdl-button--file {
right: 0;
}
}
JavaScript:
document.getElementById("uploadBtn").onchange = function () {
document.getElementById("uploadFile").value = this.files[0].name;
};
But as there's no official specification, you probably won't find an official implementation from the MDL team for now.