Filtering in the APEX Interactive Grid

Remember Oracle Forms?

One of the nice features of Forms was the use of GLOBAL items. More or less comparable to Application Items in APEX. These GLOBALS where often used to pre-query data. For example you queried Employee 200 in Form A, then opened Form B and on opening that Form the Employee field is filled with that (GLOBAL) value of 200 and the query was executed. So without additional keys strokes or entering data, when switching to another Form a user would immediately see the data in the same context. And they loved that.

In APEX you can create a similar experience using Application Items (or an Item on the Global Page) for Classic Reports (by setting a Default Value to a Search Item) and Interactive Reports (using the APEX_IR.ADD_FILTER procedure). But what about the Interactive Grid? There is no APEX_IG package ... so the first thing we have to figure out is how can we set a filter programmatically?

Start with creating an Interactive Grid based upon the good old Employees table - and add a Static ID to the Grid region : "emp". We will use the "addFilter" method to do the trick.
So, run the Page, open the Developer Toolbar of your browser and type into the console:

apex.region("emp").call("addFilter", 
                       { type       : "column" 
                       , columnType : "column" 
                       , columnName : "LAST_NAME" 
                       , operator   : "EQ" 
                       , value : "King" 
                       }); 
       
This will add a filter to your report.
Now you can add this snippet of JavaScript to a Dynamic Action that runs on Page Load. Refresh the Page and the filter is automagically applied. Woohoo. Refresh the Page again and the filter is applied. Twice. Bummer.
So before we apply a filter on a column, we need to delete existing filters on that column first. There is another method "deleteFilter", but instead of a columnName, that needs a columnId as a parameter. So how do we get the colunnId? A third method comes to the rescue : "getFilters".
Calling apex.region("emp").call("getFilters")will return an array of filter objects. Alas columnName is not one of the elements. Thus we have to figure out what the ID is of the column we're using in our filter (LAST_NAME in our example). For that information we have to dig into the model:
apex.region("emp").call("getViews").grid.modelColumns["LAST_NAME"].id; returns that id (eg 34282803428196769095).
We can use this Id to loop through our filter objects and delete the filter that matches that Id:
var vRegion = apex.region("emp");
var vFilters = vRegion.call( "getFilters" );
var vFilterColId = vRegion.call("getViews").grid.modelColumns["LAST_NAME"].id;
for ( var i in vFilters ){
     if ( vFilters[i].columnId == vFilterColId ){
       vRegion.call( "deleteFilter", vFilters[i].id );
     }  
    }   
You can see the addFilter and deleteFilter in action here on apex.oracle.com.

Now you can use this code to fire an "autoFilter" when a certain Item (on Page 0) has a value and to delete a filter when that Item has no value. You have to make sure to set that Item to a value whenever it makes sense. For instance when opening a detail page, after querying or clicking on a button or link. You also have to create a way to unset that Item ... most likely when clicking on the "delete Filter" icon (that has a jQuery selector of  "button.a-IG-button--remove").

There's a little plugin (search for manageFilter on apex.world, or go to GitHub) that can contains this code and can help you started using this stuff.

But be aware ... the methods mentioned above and that are used in the plugin are NOT DOCUMENTED. Looking in the widget.interactiveGrid.js file you will see :

/*** FOR INTERNAL USE ONLY: Subject to change in the future, please do not use! ***/

So although it might work now, there is zero guarantee it will work after your next upgrade!