Attribute Schema

An attribute schema allows users to create a series of attributes for a layer to make data collection more efficient. The schema defines the name, type, and associated properties such as an optional picklist.  Attribute schemas can also be exported and shared between users to ensure the standardization of data collection.

• Creating an Attribute Schema
• Exporting an Attribute Schema
• Importing an Attribute Schema
• Using Attribute Schemas

Creating an Attribute Schema

There are two ways to create an attribute schema within the app - for an individual feature, or for an entire layer.  Creating an attribute schema for an entire layer is often the best method as it ensures that any subsequent data collected on that layer will have access to the same attribute selections.  Creating an attribute schema for a layer can be done from within the Map View (Map Features list) or from the Layers tab directly.

To create an Attribute Schema for a layer:

Android

1. Tap beside the desired layer, then tap Edit from the menu.
2. Scroll down to the bottom of the Edit Layer dialog and tap on  next to 'New Attribute’. This will open the Edit Attribute dialog
3. Rename the attribute as desired (e.g. Tree Type)
4. Set the type of attribute
1. String - alphanumeric characters
2. Boolean - yes or no values
3. Real - numbers that can contain decimal values
4. Integer - whole numbers
5. If desired, create a pick list
1. Tap 'Edit' next to 'New pick list value'
2. Type in the appropriate value
3. Tap the back arrow to return to the Edit Attribute dialog
4. Repeat as required
6. Tap the back arrow when the attribute is complete
7. Repeat steps 3-7 for each desired attribute

iOS

1. Tap beside the desired layer, then tap Edit from the menu.
2. Scroll down to the bottom of the Edit Layer dialog and tap on next to 'Add a New Attribute’. This will open the Edit Attribute dialog
3. Rename the attribute as desired (e.g. Tree Type)
4. Set the type of attribute
• String - alphanumeric characters
• Boolean - yes or no values
• Real - numbers that can contain decimal values
• Integer - whole numbers

1. If desired, set a picklist value
1. Tap next to 'Add a New Pick List Value'
2. Type in the appropriate value
3. Tap the back arrow to return to the Edit Attribute dialog
4. Repeat as required

1. Tap the back arrow when the attribute is complete
2. Repeat steps 3-7 for each desired attribute

Example of attributes to collect for a tree inventory:

1. Tree Type > String > Pick List Values: Oak, Pine, Cedar, Maple
2. Cut (Y/N) > Boolean
3. Circumference > Real
4. Lot number > Integer > Pick List Values: 1, 2, 3, 4, 5

Android

iOS

NOTE: While attribute schemas can be created outside of the app in other software, it is currently not recommended, as Avenza Maps requires the schema to be in KML format for importing, and problems often arise when creating such files in other software packages.  If you wish to create your schema outside of Avenza Maps, the best option available is to use a text editor (e.g. Notepad++) with an existing KML schema created from the app as a template.  

Exporting an Attribute Schema

To export an attribute schema to share with other users or for use elsewhere, you will use a similar process to Exporting Map Features:

(NOTE: to re-import into Avenza Maps as a schema, the format must be set as KML)

Android

1. Open the map that has the schema you wish to export
2. Tap
3. Tap , OR tap beside the individual layer, and select Export from the menu 
4. Adjust the settings as desired
5. Under ‘Data’, choose 'Export Schema Only'

iOS

1. Open the map that has the schema you wish to export
2. Tap
3. Tap
4. Adjust the settings as desired
5. Under ‘Data’, choose 'Export Schema Only'

Importing an Attribute Schema

To import a custom schema provided to you or that you have created, you will use a similar process to Importing Map Features. The schema must be in KML format:

(NOTE: you can also import the schema to the Layers tab and choose not to link it to a map. To do so, navigate to the Layers tab and start from step 3)

Android

1. Open the map that you want the schema on
2. Tap
3. Tap
4. Tap Import layers 
5. Select the checkbox for "Import Schema Only" and navigate to the desired KML file.

iOS

1. Open the map that you want to import the schema to
2. Tap
3. Tap and select Import 
4. Toggle the ‘Import Schema Only’ switch and navigate to the desired KML file.

Once imported, the schema will be on its own layer and may require additional changes in order to be the active layer for data collection. Please see below on how to use schemas in the app.  

Using Attribute Schemas

With an active layer schema, users can begin collecting data using the pre-designed attributes, icons, and other styling settings. To collect data using a schema please follow the steps below:

1. Set the schema as the active layer on a map
   
   1. Tap beside the layer and select 'Set as active' 
2. Add a placemark to the map
3. Before confirming the addition of the feature (/ 'Submit' in the top right corner), scroll down to 'Attributes'
4. In the Attributes section, tap the attribute you need to enter data for
5. If the attribute has a picklist, choose the appropriate value, or enter a new value
6. Tap the back arrow to return to the Add Placemark screen
7. Repeat steps 4-6 for each remaining attribute
8. Tap the checkmark to confirm the placemark addition
9. Repeat for any other features