# Family Filter

A couple of people have asked for a way to hide the racier games in their collections when their kids are using the machine. I'm sure this idea appeals to a few people, but it struck me as a good candidate for a Javascript customization rather than a built-in feature, since there are lots of ways you might want to implement it.

This example shows how to create a "Family Filter" mode, which lets you show or hide your adult-themed games using a command in the Operator Menu. The Operator Menu is a good place to put a command like this, since you can limit access to it in a pin cab by physically locking the button behind the coin door. As long as you keep the coin door key safely away from the kids, they won't be able to access the menu to switch to adult mode.

## Category tags

A key PinballY feature that we'll use to implement our Family Filter mode is category tags. A category tag is a short text string that you can associate with each game. You can tag each game with as many categories as you want, so you can use these tags to represent any set of miscellaneous attributes.

For this example, we'll use the category tag "Adult" to indicate that a game should be excluded from view when in Family Filter mode. Before you can tag any games with this tag, you have to add the tag to the list that PinballY knows about. Category tags are up to you to define - there's no pre-set list that you're forced to use - so you have to go through this initial step to add a new tag to the available list:

- Bring up the Operator Menu (press the digit zero "0")
- Select Game Setup
- Select "Select Categories"
- Select Edit Category Names
- Click the New button
- Type the new category name (Adult) and click OK

Now you can add the Adult category tag to each game that you want to hide while in Family Filter mode:

- Bring up the Operator Menu (press the digit zero "0")
- Select Game Setup
- Select "Select Categories"
- Checkmark "Adult"
- Select Save

## Metafilters

The second main ingredient to implementing our family mode is the metafilter. A metafilter is a Javascript filter that sits on top of the "regular" filter (such as the era filters and manufacturer filters) to supervise the selection. Metafilters can override the regular filter's decisions about which games to include and which to exclude. This makes it easy to implement a Family Filter that excludes all games that have been tagged as "adult", regardless of which regular filter is currently selected. That lets users use the normal set of filters to slice and dice the game collection as they please, while still filtering out all of the adult-themed games.

The code for the family mode filter is pretty simple. When family filtering is in effect, all we need to do is exclude games that include the "Adult" category tag. Here's how you create the filter.

let familyFilterId; function enableFamilyFilter() { // create the filter familyFilterId = gameList.createMetaFilter({ priority: 1000, select: function(game, include) { return game.categories.indexOf("Adult") < 0; } }); }

The select function is the place where we write the selection rule for the metafilter. In this case, we only want to include games that don't have the "Adult" tag among their category tags. To determine whether or not the tag is assigned to the current game, we start by retrieving the categories property from the GameInfo object that the system passes us on each call to the select function. The categories property gives us an array of strings for all of the tags associated with the game, so we can use the Javascript array indexOf() function to search for the string of interest, "Adult". If it's there, indexOf() will return the non-negative index of the position in the array where the string was found. If it's not there, indexOf() returns -1. We want to include the game in the selection if "Adult" isn't anywhere in the array, so we return true (meaning "yes, include this game") if indexOf() returns a negative value.

Creating a filter immediately puts it into effect, so family mode is active as soon as we call enableFamilyFilter(). Now, we obviously want to be able to switch back to grown-up mode when the kids are away, so we also need a way to disable the filter after it's been created and placed into effect. That's also pretty straightforward:

function disableFamilyFilter() { // remove the filter gameList.removeMetaFilter(familyFilterId); }

When we want to remove the filter, we can simply call disableFamilyFilter(). Removing a metafilter immediately takes it out of effect, so removing the family filter will make the system stop excluding the "Adult"-tagged games.

Note that the enable and disable functions both refer to a global variable that we snuck in before the enable function, familyFilterId. We use that to remember the ID of the filter that gameList.createMetaFilter() returns, so that we can later pass that same ID to gameList.removeMetaFilter() when it's time to get rid of the filter. It's crucial that we keep track of that ID, since it's the only way to tell the system to remove the filter later.

## Adding the Operator Menu command

Our filter is ready to go. Now we just need to add the user interface to enable and disable it. Recall that our UI for the Family Filter is going to involve a new custom command in the Operator Menu. Let's look at how to add that.

The first step in adding any custom menu command is to create a command ID for the new command. This ID connects the menu item we create to the command handler that will actually carry out the command when the user selects it. When we create a command ID, we need to save it somewhere, usually a simple global Javascript variable.

let familyFilterCommand = command.allocate("FamilyFilter");

Once we have the ID, we can add the command to the desired menu. To do this, we write a handler for the Javascript "menuopen" event, which PinballY fires each time a menu is about to be displayed. This handler simply needs to insert the menu item at a desired position in the menu. You can choose whatever location you like, but it seems sensible to me to group this command with the other filter-like commands, "Show Hidden Games" and "Show Unconfigured Games". So let's add it just before the "Show Hidden Games" command.

let showHiddenCommand = gameList.getFilterInfo("Hidden").cmd; mainWindow.on("menuopen", ev => { if (ev.id == "operator") { ev.addMenuItem(showHiddenCommand, { title: "Family Filter", cmd: familyFilterCommand, checked: familyFilterOn }); } });

Note that we had to work a little harder than usual to figure out the command ID for the "Show Hidden Games" command. That's because this is technically a filter command, and filter commands don't have fixed command IDs the way most other menu commands do. To get the command ID for a filter command, we have to ask the filter. Fortunately, that's pretty easy: just a matter of calling gameList.getFilterInfo() with the ID of the filter, and grabbing the cmd property from the FilterInfo object it returns.

Now we just have write the command handler for our new menu item. We've already written the hard parts, where we do the real work of enabling and disabling the metafilter. We just have to call those functions in response to the menu selection.

// always start with the family filter activated let familyFilterOn = true; enableFamilyFilter(); // handle the Family Filter menu command mainWindow.on("command", ev => { if (ev.id == familyFilterCommand) { // toggle the current status familyFilterOn = !familyFilterOn; // enable or disable the filter according to the new status if (familyFilterOn) enableFamilyFilter(); else disableFamilyFilter(); } });

We've written this so that the family filter is automatically activated each time you start the program. This strikes me as the way most people with children would probably want it, so that you can be assured that it always starts up in the "safe" mode by default. No one will be able to get it into "adult" mode until someone with access to the coin door key shows up.

Some people might prefer to save and restore the setting. That is, if it's in adult mode when you quit a session, it should start up again in adult mode the next time you run the program, rather than always returning to family mode. I personally think the original version above, where it's always in family mode at the start of a new session, is the right approach for this particular feature. I wouldn't want to have to remember to always set the mode back to "safe" before shutting down. But the nice thing about Javascript customizations is that you don't have to agree with me on every little detail - you can make it work the way you want it to. So here's how we could rewrite the section above to save and restore the setting rather than always starting in family mode.

// restore the saved setting let familyFilterKey = "custom.FamilyFilterMode"; let familyFilterOn = optionSettings.getBool(familyFilterKey); // if the saved setting is On, enable the filter immediately if (familyFilterOn) enableFamilyFilter(); mainWindow.on("command", ev => { if (ev.id == familyFilterCommand) { // toggle the current setting, and save it in the options optionSettings.set(familyFilterKey, familyFilterOn = !familyFilterOn); // enable or disable the filter in the game list if (familyFilterOn) enableFamilyFilter(); else disableFamilyFilter(); } });