I am new with Omeka and busy with tweaking Omeka to my demands.
Now I would like to add a new menu page to the navigation bar.
This page must contain all the tags in alphabetical order to navigate to the Items.
Is there anyone how can help me to write the code.
Depending on the details of the UI you need, there's a quick, non-code option and a separate option requiring some coding.
For the non-code option, you could create a new navigation entry under Appearance->Navigation. There is already a page for items that shows tags, so you could just add a new navigation entry that goes to
/items/tags?sort_field=name as the URL.
Depending on the theme, that might produce the list of tags as a tag cloud, or as a simple list.
If you need to change the UI for those pages, it'd be a little coding to customize the display on those pages. See this guide for basics of overriding templates.
You'd want to modify the
items/tags.php page. It'll depend on the theme you're using, but something like this might give a better simple alphabetical list
<?php foreach($tags as $tag):?>
<li><a href='<?php echo html_escape(url('items/browse', array('tags' => $tag->name))); ?>' rel='tag'><?php echo metadata($tag, 'name'); ?></a></li>
<?php endforeach; ?>
Your info was very helpfull