Configuration

app/config.json carries settings your code reads, and a few that direct the compiler. ti create --alloy writes it with every section present and empty:

{
  "global": {},
  "env:development": {},
  "env:test": {},
  "env:production": {},
  "os:android": {},
  "os:ios": {},
  "dependencies": {},
  "backbone": "1.4.0"
}

Reading it

Everything outside dependencies and backbone is merged into Alloy.CFG:

{
  "global": { "apiRoot": "https://example.com/api", "pageSize": 20 },
  "env:production": { "apiRoot": "https://api.example.com" },
  "os:android": { "pageSize": 10 }
}

Ti.API.info(Alloy.CFG.apiRoot);

The sections merge in order: global, then the matching os:, then the matching env:. A key in a later section replaces the earlier one, so the production build above gets the production apiRoot and everything else from global.

env: follows the build's deploy type, not the target: a simulator build is development, --deploy-type production is production.

Compile-time constants

These are not read from config.json. The compiler replaces them with literals and then removes the dead branch, so the code in the branch not taken is not in the build at all:

Constant	True when
OS_IOS, OS_ANDROID	Building for that platform
ENV_DEV, ENV_DEVELOPMENT	Deploy type is development
ENV_TEST	Deploy type is test
ENV_PROD, ENV_PRODUCTION	Deploy type is production
DIST_ADHOC	Target is dist-adhoc
DIST_STORE	Target is dist-appstore or dist-playstore

if (OS_IOS) {
  // not present in an Android build
}

if (ENV_PRODUCTION) {
  Ti.API.info = () => {};
}

Because the substitution happens before the code is bundled, OS_IOS cannot be read as a variable, passed around, or checked with typeof. It only works as a condition written out in full.

Directing the compiler

theme selects a theme directory (see styles and themes):

{ "global": { "theme": "dark" } }

dependencies lists widgets and their versions, and a widget in app/widgets/ that is not listed here is not compiled in - which is the usual reason a <Widget> element renders nothing.

backbone pins the Backbone version Alloy bundles.

alloy.jmk

app/alloy.jmk is a build hook file, for work that has to happen around compilation - copying a file in, rewriting something generated:

task('post:compile', (event, logger) => {
  logger.info(`compiled ${event.dir.project}`);
});

Tasks are pre:load, post:load, pre:compile, post:compile. Use it sparingly: it runs on every build and a slow task is felt on every save.

Next

Distributing apps covers signing and shipping what you have built.