# @tangle/graph > a helper for building + updating traverseable tangle graphs Latest version **3.2.0** (published 2023-04-04) · LGPL-3.0-only license · 0 weekly downloads ## Install ```sh npm install @tangle/graph pnpm add @tangle/graph yarn add @tangle/graph bun add @tangle/graph ``` ## Health **Score 15/100 (F)** — status: abandoned. Positive: no vulnerabilities. Warnings: low downloads; no types; no esm support. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 3.2.0 | | Published | 2023-04-04 | | First published | 2020-09-30 | | Weekly downloads | 0 | | License | LGPL-3.0-only | | TypeScript types | none | | Module format | CommonJS | | Dependencies | 2 | | Unpacked size | 50.2 KB | | Known vulnerabilities | 0 (+1 in 1 direct dependencies) | | Install scripts | no | | Author | mixmix | | Maintainers | mixmix, chereseeriepa, cpilbrow | | Keywords | tangle, dag, graph | ## Links - npm: https://www.npmjs.com/package/@tangle/graph - Repository: https://gitlab.com/tangle-js/tangle-graph - Homepage: https://gitlab.com/tangle-js/tangle-graph#readme - Issues: https://gitlab.com/tangle-js/tangle-graph/-/issues - npm.io page: https://npm.io/package/@tangle/graph ## Dependencies (2) - [lodash.set](https://npm.io/package/lodash.set.md) ^4.3.2 - [lodash.clone](https://npm.io/package/lodash.clone.md) ^4.5.0 ## Alternatives - [apollo-link-http-common](https://npm.io/package/apollo-link-http-common.md) — 879.0K weekly downloads - [react-relay](https://npm.io/package/react-relay.md) — 336.8K weekly downloads - [relay-test-utils](https://npm.io/package/relay-test-utils.md) — 181.6K weekly downloads - [@vendure/core](https://npm.io/package/@vendure/core.md) — 14.8K weekly downloads - [@pnpm/deps.graph-sequencer](https://npm.io/package/@pnpm/deps.graph-sequencer.md) — 13.4K weekly downloads ## Recent versions - 3.2.0 (latest) — 2023-04-04 - 3.1.0 — 2023-04-04 - 3.0.2 — 2023-03-01 - 3.0.1 — 2023-03-01 - 3.0.0 — 2021-10-25 - 2.1.0 — 2020-12-16 - 2.0.0 — 2020-12-16 - 1.3.1 — 2020-12-03 - 1.3.0 — 2020-11-29 - 1.2.0 — 2020-10-30 - 1.1.0 — 2020-10-08 - 1.0.2 — 2020-10-01 - 1.0.1 — 2020-09-30 ## README # @tangle/graph A module which allows you to build a simple graph, and provides simple helper methods for modifying an querying that graph. ## Example Usage ```js const Graph = require('@tangle/graph') // A (root) // / \ | // B C | causality // \ / V // D const nodes = [ { key: 'A', previous: null, // << signals this is a rootNode data: { comment: 'What shall we have for dinner?', items: { pizza: 1 } } }, { key: 'B', previous: ['A'], data: { comment: 'Hows about spaghetti?', items: { spaghetti: 1 } } }, { key: 'C', previous: ['A'], data: { comment: 'My only constraint is no wheat.', items: { wheat: -1 } } }, { key: 'D', previous: ['C', 'D'], data: { comment: 'Everyone ok with glutten-free spaghetti?', items: { spaghetti: 1 } } } ] const graph = new Graph (nodes) graph.isMergeNode('D') // => true ``` ## API ### `new Graph(nodes) -> graph` Creates a Graph instance which builds a model of the graph. Notably builds a graph based on links where: All of these graph methods assume you're passing in nodes which have : - a `key` property which is unique - a `previous` property which an array of keys for nodes that are directly _before_ this key-node in the graph. - an optional `data` property which can contain anything In scuttlebutt the keys are the hash addresses of the messages ### `graph.getNode(key) => result` where `result` is: - `node` if it's _connected_ within the graph - `null` if it's _disconnected_ - `undefined` if it was not in the set of nodes passed in ### `graph.isConnected(key) => Boolean` ### `graph.getNext(key) => [key]` Returns an Array of keys of nodes that are causally linked to this node-key. This contains keys of nodes _after_ this key-node in the graph. (alias: `graph.getLinks`) ### `graph.getPrevious(key) => [key]` This returns the `previous` property for a given node. This contains keys of nodes _before_ this key-node in the graph. (alias: `graph.getBacklinks`) ### `graph.isBranchNode(key) => Boolean` Tells you whether the graph diverges as you proceed from the given node-key. (basically `graph.getLinks(key).length > 1`) ### `graph.isMergeNode(key) => Boolean` Tells you if 2 or more branches converge in the given node-key. (basically `graph.getPrevious(key).length > 1`) ### `graph.isTipNode(key) => Boolean` Tells you whether the given node-key belongs to a _tip_ of the graph, i.e. a leading tip causally (basically `graph.getNext(key).length === 0`) ### `graph.invalidateKeys(keys) Takes an Array of node keys and prunes them from the graph. **Note** this also prunes all nodes down-stream of those nodes. This is an opinion baked into the tangle spec - that a node is only valid if it extends from other valid nodes. ### `graph.rootNodes => [Node]` A getter which gives you access to an Array of root nodes (i.e. are the starting points of the graph) ### `graph.rootKeys => [Key]` A getter which gives you access to an Array of keys for nodes which are "roots" within the graph (i.e. are the starting points of the graph) (alias: `graph.rootNodeKeys`) ### `graph.tipNodes => [Node]` A getter which gives you access to an Array of tip nodes (i.e. are the ending points of the graph) ### `graph.tipKeys => [Key]` A getter which gives you access to an Array of keys for nodes which are "tips" within the graph (i.e. are the ending points of the graph) (alias: `graph.tipNodeKeys`) ### `graph.raw` A getter which gives you access to `{ linkMap, backlinkMap }`. These are data structures which map the links of the graph in both directions. ### `graph.getHistory(key) => [key]` A function that gets the keys of all nodes earlier in the graph of a given node. This goes all the way back to the root, not just the directly previous nodes. --- ## NOTES this is expected to be used with DAGs (directed acyclic graphs), but there is currently no internal check built to guarantee this --- _Source: https://npm.io/package/@tangle/graph · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._