CommCare can generate SMS messages
- From the server
- Directly from the user's phone
Each option has distinct advantages and disadvantages. For a full discussion of server-based SMS messages, see CommCare Messaging. The server-based functionality provides automated messages without requiring user interaction, has a rich feature set for scheduling messages and selecting who receives a message and automatically bills the costs of the messages to the project. However, before a user action can trigger and schedule a message, the user needs to have data connectivity and successfully sync with the server.
Occasionally, a user may have cell reception and therefore can send an SMS directly but does not have data connectivity. Furthermore, users may want to customize a message and have the same functionality as they are used to experience with their phone's default SMS application. In these situations, CommCareODK can automatically pre-populate a new SMS using Android's default SMS application with a list of recipients and message content. The user then simply needs to click "send." The SMS cost is charged to the user's SIM card, as any regular SMS would be, and the SMS appears in the user's message history.
This experience can be implemented using the Android app callout functionality.
- Create a hidden variable named sms_message. Populate it with the text string that should appear in the message body.
- Create a hidden variable named sms_addresses. Populate it with the comma-separated list of phone numbers of the intended recipients.
- Insert an Android app callout; then edit the resulting XForms XML to match the example below. The "button-label" and the "data" attributes in particular for the "odkx:intent" element currently can only be set in XML.
Once deployed on an Android phone, the question should display a button labelled "Send SMS". Clicking the button will launch the phone's default SMS application with a new pre-populated message.