When filtering posts inside any channels or thru virtual channels, Newzie allows you to set multiple filters so that you can define that exact filtering scenario that you have in mind.
Best way of describing how defining multiple filters is better than defining one is to give an example. Following scenario examplifies that advantage.
Assume that you like to create a virtual channel filter and monitor Mars related posts in the system. Here are the related words that you come up with; NASA, Mars, Red Planet, Opportunity, Spirit, and rover.
You know that you cannot assume that when any one of these words occur in one post, that post is Mars related because in some cases word NASA may occur in the content which is nothing to do with Mars, and sometimes author of the post can be so reluctant to type Mars with capital but "mars." Moreover, even though you enter words "Opportunity" and "Spirit" considering the case sensitivity, posts containing those words may talk about anything but Mars.
Hence you need to define right dependencies between words to gather as much posts as possible without accepting unrelated posts along with other related ones.
First impression might be it is impossible to create the right filter for this scenario. That is because you cannot satisfy given case above with one filter alone. Here is where multiple filters help you define this wide filter space. Lets first define one filter as follow.
- Create filter with phrase "Red Planet" and word "Mars"; case insensitive; OR relation
Given example filter above checks posts for occurances of word 'Mars' and phrase 'Red Planet' without considering case sensitivity and since relation between two words is defined as OR-relation, it means that when any one of those two words occurs in the content of a post, filter catches that post. Different than OR-relation, AND-relation necessitates the occurance of both words together in that post.
To satisfy the scenario given above, here are more filters that you can define for that virtual channel.
- Create filter with words "Opportunity" and "rover"; case sensitive; AND relation
- Create filter with words "Spirit" and "rover"; case sensitive; AND relation
- Create filter with words "Opportunity" and "Mars";case insensitive; AND relation
- Create filter with words "Spirit" and "Mars";case insensitive; AND relation
- Create filter with words "Opportunity", "NASA";case insensitive; AND relation
- Create filter with words "Spirit", "NASA";case insensitive; AND relation
- Create filter with phrase "Red Planet", and word "Opportunity"; case sensitive; AND relation
- Create filter with phrase "Red Planet", and word "Spirit"; case sensitive; AND relation
After adding these filters into the Virtual Channel, when checked post matches with one of these filters, it is accepted by that Virtual Channel and moved into that.
It has to be noted that given scenario above is divided into word pairs and differences between case sentivitiy and AND/OR relations are determined based on mainly proper nouns in the pair, such as Mars and NASA.
Ordering Filters Matters
Recall that when checked post is matched with given criteria of a filter, based on the behaviour of that filter, that post is filtered in or filtered out. For example, all given filters above filters in, that is, accepts matched posts. When checked post is matched with filter whose behaviour is set as filter-out, that matched post is rejected. Hence by using filters with filter-out behaviour, you can reject specific posts from being accepted by any virtual channel.
Because of the fact that given above, when defining multiple filters with different behaviours, you have to pay attention to the ordering of those filters, since first matched filter determines the action on that post. For example, if first matched filter has filter-out behaviour, that post is rejected, even though another filter coming after that filter in the order accepts it.