Thanks for your patience in awaiting my progress report. Adding an “exclude” feature to the Search Media and Terms Search functions turned out to be more, well, interesting than I expected.
First, simply adding a “not” or “not in” alternative to the existing logic does not work because items can have multiple term assignments and each assignment is independent, with a separate database entry. Using the example of “property” and “not features”, the item you want to exclude has two separate term assigmments, “property” and “features”. The simple SQL is something like SELECT TERM IN ('PROPERTY') AND TERM NOT IN ('FEATURES'). The items assigned to both terms still show up because the PROPERTY term assignment passes both tests.
The “right” answer is more along the lines of 1) select all the items assigned to PROPERTY, and then 2) remove all the items assigned to FEATURES. Two queries are required to get the answer that makes sense.
Second, there are three methods to filter the items displayed and a good solution must work for all combinations of the methods. The Media/Assistant screen has 1) a dropdown control for filtering items by one specific term, 2) the “Search Media” text box and 3) the “Terms Search” popup window. As you observed, you can set the dropdown control and then add the Search Media text to further refine the results. You can also enter a Search Media value for, say, the Title and Description values and then use “Terms Search” to further refine the results.
Finally, the Search Media and Terms Search methods allow for multiple phrases and terms, connected by AND or OR, and phrases can have multiple words. For example, you could search for "PERSONAL PROPERTY" OR "REAL PROPERTY" and exclude TANGIBLE, which would also exclude items assigned to "COMMUNITY PROPERTY". Note the quotes around the multi-word phrases.
The solution is to provide “exclude” delimiters (“/”) you can use to enclose any part of the Search Media or Terms Search values. The values are divided into two sub-values, “positive” and “negative”, with everything enclosed by the exclude delmiters going to the negative sub-value and everything else to the positive. Two queries are performed. First, the negative sub-value is used and a list of the item ID values that pass the query is compiled. Second, the positive sub-value is used and items with the “negative” ID values are excluded.
The example can be entered in the Search Media box as property /features/, or you can select “property” in the dropdown control and enter /features/ in the Search Media box, or you can enter property in the Search Media Box, click “Terms Search” and enter /features/ in the popup window. Of course, the “Terms” box below the Search Media box must be checked as well.
I have uploaded a new MLA Development Version dated 20190122 that contains the new feature. You can find step-by-step instructions for using the Development Version in this earlier topic:
PHP Warning on media upload with Polylang
If you get a chance to try the Development Version please let me know how it works for you. Thanks for motivating this useful MLA enhancement. I will work on adding the feature to the [mla_gallery] shortcode as time permits.
