@swim/dataflow

@swim/dataflow implements a compiler from @swim/structure selectors, operators, and functions, to continuously updated data structures driven by @swim/streamlet dataflow graphs. @swim/dataflow turns dynamic data structures into living documents. @swim/dataflow is written in TypeScript, but can be used from either TypeScript or JavaScript. @swim/dataflow is part of the @swim/core framework.

Overview

A live updated data structure is represented as a RecordScope, which extends Record from @swim/structure. An ordinary Record can be recursively compiled into a RecordScope by invoking the RecordScope.from factory method. A compiled RecordScope has all of its nested expressions replaced by their evaluated state. But unlike evaluating a Record with an Interpreter, if a member of a RecordScope changes, all expressions that transitively depend on that member get flagged for recomputation, which occurs the next time reconcileInput gets invoked on the RecordScope.

The Dataflow.compile method can also be used to compile an arbitrary @swim/structure expression into an Outlet that updates whenever the state of any of its transitively dependend expressions changes.

Installation

npm

For an npm-managed project, npm install @swim/dataflow to make it a dependency. TypeScript sources will be installed into node_modules/@swim/dataflow/main. Transpiled JavaScript and TypeScript definition files install into node_modules/@swim/dataflow/lib/main. And a pre-built UMD script can be found in node_modules/@swim/dataflow/dist/main/swim-dataflow.js.

Browser

Browser applications can load swim-core.js, which comes bundled with the @swim/dataflow library, directly from the Swim CDN.

<script src="https://cdn.swim.ai/js/latest/swim-core.js"></script>

Alternatively, the standalone swim-system.js script may be loaded from the Swim CDN, which bundles @swim/dataflow together with all other @swim/system libraries.

<script src="https://cdn.swim.ai/js/latest/swim-system.js"></script>

Usage

ES6/TypeScript

@swim/dataflow can be imported as an ES6 module from TypeScript and other ES6-compatible environments.

import * as dataflow from "@swim/dataflow";

CommonJS/Node.js

@swim/dataflow can also be used as a CommonJS module in Node.js applications.

var dataflow = require("@swim/dataflow");

Browser

When loaded by a web browser, the swim-core.js script adds all @swim/dataflow library exports to the global swim namespace.

The swim-system.js script also adds all @swim/dataflow library exports to the global swim namespace, making it a drop-in replacement for swim-core.js when additional @swim/system libraries are needed.