The terms <dfn>MIDI</dfn>, <dfn>MIDI device</dfn>, <dfn>MIDI input

port</dfn>, <dfn>MIDI output port</dfn>, <dfn>MIDI interface</dfn>,

<dfn>MIDI message</dfn>, <dfn>MIDI System Real-Time message</dfn> and

</p>

</section>

<section>

</p>

<p>

Requesting MIDI access SHOULD prompt the user for access to MIDI

some scenarios, this permission may have already been implicitly

or explicitly granted, in which case this prompt may not appear.

If the user gives express permission or the call is otherwise

approved, the vended Promise is resolved. The underlying system

may choose to allow the user to select specific MIDI interfaces

to expose to this API (i.e. pick and choose interfaces on an

individual basis), although this is not required. The system may

privacy and security implications.

</p>

<p>

Prompt the user in a user-agent-specific manner for

permission to provide the entry script's origin with a

{{MIDIAccess}} object representing control over user's MIDI

enable or disable that access.

</p>

<p>

<dd>

<p>

This member informs the system whether the ability to send and

given {{MIDIAccess}} object. On the option passed to

{{requestMIDIAccess()}}, if this member is set to true, but

action), the access request will fail with a {{"SecurityError"}}

error. If this support is not requested (and allowed), the system

messages received on the port.

</p>

</dd>

<dfn>sysexEnabled</dfn>

</dt>

<dd>

enabled on this MIDIAccess.

</dd>

</dl>

</li>

<li>

<p>

process.

</p>

</li>

a valid MIDI message, throw a <code>TypeError</code> exception.

</p>

<p>

<code>InvalidAccessError</code> exception.

</p>

<p>

</section>

<section>

<h3>

</h3>

<p>

This example shows how to request access to the MIDI system,

messages.

</p>

<pre class="example">var midi = null; // global MIDIAccess object

</h3>

<p>

This example loops all input messages on the first input port to

</p>

<pre class="example">var midi = null; // global MIDIAccess object

var output = null;

a sampler - or replace that data (erasing sample data or patches in

the device), although both these scenarios would have to be coded for

a particular device. It is also possible that some samplers might

the sampler happened to have a dedicated microphone attached

(uncommon in practice, but possible), it would be possible to write

code specific to a particular device that could record a short sample

samples/user configuration could uniquely identify the system

(although again, this requires much device-specific code; there is

not standardized “grab all patches and hash it” capability.) This

category of their own.

</li>

</ol>

</li>

<li>Sending and receiving SysEx - obviously, for more advanced

communication with high-end hardware devices, SysEx is required.

to program patches, send advanced controller messages, download

firmware, etc., which are much-demanded scenarios for Web MIDI. Some

devices use sysex as a direct control protocol, as they can pack more

not persistently.

</p>

<p>

potential, and it seems that distinguishing requests for SysEx

separately in the API is a good idea, in order to more carefully

provide user security hooks. The <a data-lt=

"Navigator.requestMIDIAccess">suggested security model</a> explicitly

allows user agents to require the user's approval before giving

access to MIDI devices, although it is not currently required to

</p>

</section>

</section>