HTML5: Change placeholder input color with CSS

Implementation to change placeholder color

There are three different implementations: pseudo-elements, pseudo-classes, and nothing.

• WebKit and Blink (Safari, Google Chrome, Opera 15+) are using a pseudo-element: ::-webkit-input-placeholder.
• Mozilla Firefox 4 to 18 is using a pseudo-class : :-moz-placeholder (one colon).
• Mozilla Firefox 19+ is using a pseudo-element: ::-moz-placeholder, but the old selector will still work for a while.
• Internet Explorer 10 is using a pseudo-class : :-ms-input-placeholder.

IE up to version 9 and Opera up to version 12 do not support any CSS selector for placeholders.

The discussion about the best implementation is still going on. Note the pseudo-elements act like real elements in the Shadow DOM. A padding on an input will not get the same background color as the pseudo-element.

CSS selectors

User agents are required to ignore a rule with an unknown selector. See Selectors Level 3:

a group of selectors containing an invalid selector is invalid.

So we need separate rules for each browser. Otherwise the whole group would be ignored by all browsers.

::-webkit-input-placeholder { /* WebKit browsers */
    color:    #999;
}
:-moz-placeholder { /* Mozilla Firefox 4 to 18 */
    color:    #999;
    opacity:  1;
}
::-moz-placeholder { /* Mozilla Firefox 19+ */
    color:    #999;
    opacity:  1;
}
:-ms-input-placeholder { /* Internet Explorer 10+ */
    color:    #999;
}

Usage notes

• Be careful to avoid bad contrasts. Firefox's placeholder appears to be defaulting with a reduced opacity, so needs to use opacity: 1 here.
• Note that placeholder text is just cut off if it doesn’t fit – size your input elements in em and test them with big minimum font size settings. Don’t forget translations: some languages need more room for the same word.
• Browsers with HTML support for placeholder but without CSS support for that (like Opera) should be tested too.
• Some browsers use additional default CSS for some input types (email, search). These might affect the rendering in unexpected ways. Use the properties -webkit-appearance and -moz-appearance to change that. Example:

    [type="search"] {

        -moz-appearance:    textfield;
        -webkit-appearance: textfield;
        appearance: textfield;
    }

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PHP: Save HTML5 canvas as an image in a server

Here is an example how to achieve what you need:

1) Draw something (taken from canvas tutorial)

<canvas id="myCanvas" width="578" height="200"></canvas>
<script>
    var canvas = document.getElementById('myCanvas');
    var context = canvas.getContext('2d');

    // begin custom shape
    context.beginPath();
    context.moveTo(170, 80);
    context.bezierCurveTo(130, 100, 130, 150, 230, 150);
    context.bezierCurveTo(250, 180, 320, 180, 340, 150);
    context.bezierCurveTo(420, 150, 420, 120, 390, 100);
    context.bezierCurveTo(430, 40, 370, 30, 340, 50);
    context.bezierCurveTo(320, 5, 250, 20, 250, 50);
    context.bezierCurveTo(200, 5, 150, 20, 170, 80);

    // complete custom shape
    context.closePath();
    context.lineWidth = 5;
    context.fillStyle = '#8ED6FF';
    context.fill();
    context.strokeStyle = 'blue';
    context.stroke();
</script>

2) Convert canvas image to URL format (base64)

var dataURL = canvas.toDataURL();

3) Send it to your server via Ajax

$.ajax({
  type: "POST",
  url: "script.php",
  data: { 
     imgBase64: dataURL
  }
}).done(function(o) {
  console.log('saved'); 
  // If you want the file to be visible in the browser 
  // - please modify the callback in javascript. All you
  // need is to return the url to the file, you just saved 
  // and than put the image in your browser.
});

3) Save base64 on your server as an image (here is how to do this in PHP:

My best guess is that you simply need to call base64_decode() on $_REQUEST['data'] before writing it to the file.

The same ideas is in every language. Server side in PHP can be found here):

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