Editing Contribute: Plugins/ExportPluginsHelloOld (section)

== Constructor ==
After the implicit class reference, a hash of options is given.
<pre>
        my ($class, %opts) = @_;
</pre>

We create a new export plugin by calling the Eprints::Plugin::Export constructor
<pre>
        my $self = $class->SUPER::new(%opts);
</pre>
Now we set a number of fields to register our new plugin.

This is the name that will appear in the export dropdown menu. The name should therefore be short and descriptive.
<pre>
        $self->{name} = 'Hello, World!';
</pre>

The accept field is a list containing the types of objects this
plugin can deal with. In this case lists of eprints and individual
eprints.
<pre>
        $self->{accept} = [ 'dataobj/eprint', 'list/eprint' ];
</pre>
The visible field denotes the class of user which will be able to see the plugin.
For most export plugins the value 'all' will be required, allowing
all users to see and use the plugin. A value of 'staff' would
make the plugin visible only to repository staff.
<pre>
        $self->{visible} = 'all';
</pre>
The suffix field contains the extension of files exported by the plugin.

The mimetype field defines the [http://en.wikipedia.org/wiki/MIME MIME] type of the files exported by the plugin
You can also specify file encoding, for example 'text/plain; charset=utf-8' to specify plain text, encoded using UTF-8.[http://en.wikipedia.org/wiki/UTF-8 UTF-8] is a Unicode character encoding capable of expressing characters from a large number of character sets and so is usually preferable to [http://en.wikipedia.org/wiki/ASCII ASCII]
<pre>
        $self->{suffix} = '.txt';
        $self->{mimetype} = 'text/plain; charset=utf-8';
</pre>

We then return our plugin reference.
<pre>
        return $self;
</pre>