I need a component for read and unread articles.
For example, when a user is logged into the Joomla site, the component should list only unread articles. If the user reads an article, it should change status from unread to read, and should not be shown in the component where your read articles are shown.
Does something like this exist? Thanks for your time!
As far as I know there isn't such component available. That is a pretty neat idea actually. The problem right now with for example the article manager would be that, there is no information stored about who is reading what. We have a hits field and that is all. Something more that I've noticed is that the users table "last logged in" field is immediately updated when a user logs in. So you can't use it for reference about the last time the currently logged in person logged on the site.
To achieve what you want you'll need to create a new component (maybe you could also achieve it with a plugin and a template override). You component should store the user id, the article ids, the last time the user logged in. Then on the base of this information you could show only articles that are relevant to the user.
not to create a special component for your needs you can simply find a blog component you prefer and leave an inquiry for customization. As far as I know, customization will not take a lot of time. Particularly, i suggest looking at JoomBlog component and if you like the functionality contact support team.
I think you need a plugin for this task. The plugin should check user-id and the article-id and save this in the database. And then with the onContentBeforeDisplay Plugin event you can hide this article with some simple php checks.
Plugin Events: http://docs.joomla.org/Plugin/Events
General Plugin Development: http://docs.joomla.org/Portal:Plugin_Development
Did you ever find something to answers your unread article need? I am looking for something similar.