A walkthrough of building new apps on top of the Indivo iOS framework, as well as integrating it with existing apps to cloud-enable them. By Pascal Pfiffner, MD Ph.D., Children's Hospital Informatics Program

1. Indivo iOS
framework

2. Goals
• Drop-in to existing Cocoa projects
• Provide a low entry barrier into PHR
• Make Indivo a viable choice for App developers
who want to move their users’ data into the cloud

3. The framework
• Handles authentication (OAuth)
• Provides Indivo objects (automatic XML handling)
• Knows where an object comes from (REST paths)
• Provides messaging functionality

4. Handling OAuth
• Class INServerCall to encapsulate requests
• Uses MPOAuth, an OSS OAuth framework for
iOS, transparently
‣ OAuth is handled for you

5. From Schema to Cocoa
• The developer should not have to deal with XML
serialization/deserialization
‣ Provide classes for all Indivo document types
• We have to write Objective-C classes for all types
‣ A generator creates Cocoa classes from Indivo’s
XSD and SDMJ schemas

6. Self-aware objects
• Document objects know their record
• Records know their server
• Framework knows the server actions
‣ REST methods can be inferred for all tasks

7. iOS framework
Abstract logic into Cocoa objects
selectRecord:
Server Record
addDocumentOfClass:
fetchReportsOfClass:
push:
Docs replace:
archive:
...

8. App Flow
Setup
server = [IndivoServer serverWithDelegate:self];
#define kIndivoFrameworkServerURL @“http://10.17.20.127:8000”
#define kIndivoFrameworkUIServerURL @“http://10.17.20.127:8001”
#define kIndivoFrameworkAppId @“medsample@apps.indivo.org”
#define kIndivoFrameworkConsumerKey @“nkd8cg02mgo34sntkao9”
#define kIndivoFrameworkConsumerSecret @“1acgk9804wkmraoceu02”

9. App Flow
Logging in
[server selectRecord:^{ }];
server.activeRecord

10. App Flow
Adding a medication
Medication *med = [record addDocument:Medication];
med.drugName = [INCodedValue new];
med.drugName.title = @“Tylenol”;
med.drugName.system ...
[med push:^{ }];

11. App Flow
Sending a message
[med.activeRecord sendMessage:@“New medication added”
withBody:@“See medlist app”
ofType:INMessageTypePlaintext
severity:INMessageSeverityMedium
attachments:nil
callback:^{ }];

12. Integrating Indivo Into
Existing Apps

13. Growth Charts App

14. Growth Charts App
Data Models
CHPatientSource selectPatient:^{ }
CHPatient ageAtDate:
measurementSetsContainingDataTypes:
CHMeasurementSet date
CHMeasurement value
CHMeasurement value
CHMeasurement value

15. Growth Charts App
Local Data Source
• Override selectPatient:
• Instantiate a CHPatient
• Read CSV data as measurement sets

16. Growth Charts App
Indivo Data Source
• Call Indivo’s selectRecord: method
• Within the callback block:
• Fetch patient demographics
• Create CHPatient with record demographics
• Fetch patient’s vitals
• Convert Indivo vitals into measurement sets

17. Growth Charts App
Indivo-Enabled (read-only)
• 2 lines + app setup file to setup Indivo server
instance
• 9 lines to convert IndivoRecord to CHPatient
• 21 lines to convert Indivo vitals into
CHMeasurementSet

18. Documentation
• Take a look at README.md
• Checkout the sample medication app
• Technical documentation available online:
http://docs.indivohealth.org/projects/indivo-x-ios-
framework/en/latest/

19. Playing with Medications

20. Version 2.0 α
Available with the other Indivo sources from:
https://github.com/chb/IndivoFramework-ios
Checkout branch dev_two (tag hackathon_2012)