Displaying Data in the ListView

The next step in the making of your app is creating a way to see all the accessbile places. You want to program it so that it finds all the place entries and then adds each one as an element of the ListView in the ListOfPlaces screen. To do this, you are to need the FirebaseDB component again.

• Switch to the ListOfPlaces screen and drag out a FirebaseDB component onto the Designer view.

• Now switch over to the Blocks view, and take out a when ListOfPlaces.Initialize block. Everything in this will run as soon as this screen opens up.

• Place a call FireBase.GetTagList block inside this block. This tells Firebase to return a list containing the tags of all saved data in your database.

• Take out a when FireBase.TagList block and insert a for each item in list block inside it. This function will run as soon as Firebase gets our collection of tags in the form of a list, which it uses as the value variable.

With the for loop you now have individual tags being set to the item variable. Of course you don’t want the tag, you want the address, and you’ll use the tag to get it.

Grab a call Firebase.GetValue block, and set the tag to the item variable, since this contains the current tag from the value list.

• Add a when Firebase.GotValue block, and put a add items to list block inside it.

• You will need a list to add locations to, so add an initialize global name block. Change its name to locations and drag a create empty list block onto the end of it.

• Now attach a get global locations block to the list attachment of the add items to list block, and a get value block to the item attachment. The value variable contains the address of the place.

Note: the list of tags will also contain the "PlaceNumber" tag that you’re using to keep count of the places, so you’ll need to exclude that from the list you display.

• Add an if then block from Control to your GotValue block, and move the add items to list code so it’s inside the then block.

• Onto the if part: attach a not and an = from Logic. Hover over the tag variable and put a get tag on the left of the =. tThen put a "" Text block on the right and type "PlaceNumber" into it.

• Lastly you need to tell the ListView to get its elements from your list. Get a set ListView.Elements block and attach a get global locations block to it.