workflow

Workflow is an application framework that provides architectural primitives.

Workflow is:

• Written in and used for Kotlin and Swift
• A unidirectional data flow library that uses immutable data within each Workflow.

Data flows in a single direction from source to UI, and events in a single direction from the UI to the business logic.

• A library that supports writing business logic and complex UI navigation logic as

state machines, thereby enabling confident reasoning about state and validation of correctness.

• Optimized for composability and scalability of features and screens.
• Corresponding UI frameworks that bind Rendering data classes for “views”

(including event callbacks) to Mobile UI frameworks for Android and iOS.

• A corresponding testing framework that facilitates simple-to-write unit

tests for all application business logic and helps ensure correctness.

Using Workflows in your project

Maven Artifacts

Artifacts are hosted on Maven Central. If you're using Gradle, ensure mavenCentral() appears in your repositories block, and then add dependencies on the following artifacts:

Maven Coordinates	Depend on this if…
com.squareup.workflow1:workflow-core-jvm:x.y.z	You are writing a library module/project that uses Workflows, but you don't need to interact with the runtime from the outside.
com.squareup.workflow1:workflow-rx2:x.y.z	You need to interact with RxJava2 from your Workflows.
com.squareup.workflow1:workflow-testing-jvm:x.y.z	You are writing tests. This should only be included as a test dependency.
com.squareup.workflow1:workflow-ui-core-android:x.y.z	You're writing an Android app that uses Workflows.

Lower-level Artifacts

Most code shouldn't need to depend on these directly. They should generally only be used to build higher-level integrations with UI frameworks.

Maven Coordinates	Depend on this if…
com.squareup.workflow1:workflow-runtime-jvm:x.y.z	You need to interact directly with the runtime, i.e. streams of renderings and outputs.
com.squareup.workflow1:workflow-ui-core-common-jvm:x.y.z	You are writing workflow-ui-android for another UI framework. Defines the core types used by that artifact.

Jetpack Compose support

Jetpack Compose is the new UI toolkit for Android. It is comparable to SwiftUI for iOS. The main UI artifacts in this repository support standard Android Views, but various types of Compose integrations are provided under the compose folder.

You'll find workflow + compose info and documentation there.

Resources

• Wondering why to use Workflow? See

"Why Workflow"

• There is a Glossary of Terms
• We have a User Guide

describing core concepts.

• For Kotlin (and Android), there is a codelab style

tutorial in the repo.

• For Swift (and iOS), there is also a Getting Started

tutorial in the repo.

• There are also a number of

Kotlin samples and Swift samples.

Support & Contact

Workflow discussion happens in the Workflow Community slack. Use this open invitation.

Workflow maintainers also hang out in the #squarelibraries channel on the Kotlin Slack.

Releasing and Deploying

See RELEASING.md.

License

Copyright 2019 Square Inc.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.