mirror of https://gitee.com/bigwinds/arangodb
253 lines
7.0 KiB
Markdown
253 lines
7.0 KiB
Markdown
<!-- don't edit here, its from https://@github.com/arangodb/arangodbjs.git / docs/Drivers/ -->
|
|
# GraphEdgeCollection API
|
|
|
|
The _GraphEdgeCollection API_ extends the
|
|
[_Collection API_](../Collection/README.md) with the following methods.
|
|
|
|
## graphEdgeCollection.remove
|
|
|
|
`async graphEdgeCollection.remove(documentHandle): Object`
|
|
|
|
Deletes the edge with the given _documentHandle_ from the collection.
|
|
|
|
**Arguments**
|
|
|
|
* **documentHandle**: `string`
|
|
|
|
The handle of the edge to retrieve. This can be either the `_id` or the `_key`
|
|
of an edge in the collection, or an edge (i.e. an object with an `_id` or
|
|
`_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
|
|
await collection.remove('some-key')
|
|
// document 'edges/some-key' no longer exists
|
|
|
|
// -- or --
|
|
|
|
await collection.remove('edges/some-key')
|
|
// document 'edges/some-key' no longer exists
|
|
```
|
|
|
|
## graphEdgeCollection.edge
|
|
|
|
`async graphEdgeCollection.edge(documentHandle): Object`
|
|
|
|
Retrieves the edge with the given _documentHandle_ from the collection.
|
|
|
|
**Arguments**
|
|
|
|
* **documentHandle**: `string`
|
|
|
|
The handle of the edge to retrieve. This can be either the `_id` or the `_key`
|
|
of an edge in the collection, or an edge (i.e. an object with an `_id` or
|
|
`_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
|
|
const edge = await collection.edge('some-key');
|
|
// the edge exists
|
|
assert.equal(edge._key, 'some-key');
|
|
assert.equal(edge._id, 'edges/some-key');
|
|
|
|
// -- or --
|
|
|
|
const edge = await collection.edge('edges/some-key');
|
|
// the edge exists
|
|
assert.equal(edge._key, 'some-key');
|
|
assert.equal(edge._id, 'edges/some-key');
|
|
```
|
|
|
|
## graphEdgeCollection.save
|
|
|
|
`async graphEdgeCollection.save(data, [fromId, toId]): Object`
|
|
|
|
Creates a new edge between the vertices _fromId_ and _toId_ with the given
|
|
_data_.
|
|
|
|
**Arguments**
|
|
|
|
* **data**: `Object`
|
|
|
|
The data of the new edge. If _fromId_ and _toId_ are not specified, the _data_
|
|
needs to contain the properties __from_ and __to_.
|
|
|
|
* **fromId**: `string` (optional)
|
|
|
|
The handle of the start vertex of this edge. This can be either the `_id` of a
|
|
document in the database, the `_key` of an edge in the collection, or a
|
|
document (i.e. an object with an `_id` or `_key` property).
|
|
|
|
* **toId**: `string` (optional)
|
|
|
|
The handle of the end vertex of this edge. This can be either the `_id` of a
|
|
document in the database, the `_key` of an edge in the collection, or a
|
|
document (i.e. an object with an `_id` or `_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const db = new Database();
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
const edge = await collection.save(
|
|
{some: 'data'},
|
|
'vertices/start-vertex',
|
|
'vertices/end-vertex'
|
|
);
|
|
assert.equal(edge._id, 'edges/' + edge._key);
|
|
assert.equal(edge.some, 'data');
|
|
assert.equal(edge._from, 'vertices/start-vertex');
|
|
assert.equal(edge._to, 'vertices/end-vertex');
|
|
```
|
|
|
|
## graphEdgeCollection.edges
|
|
|
|
`async graphEdgeCollection.edges(documentHandle): Array<Object>`
|
|
|
|
Retrieves a list of all edges of the document with the given _documentHandle_.
|
|
|
|
**Arguments**
|
|
|
|
* **documentHandle**: `string`
|
|
|
|
The handle of the document to retrieve the edges of. This can be either the
|
|
`_id` of a document in the database, the `_key` of an edge in the collection,
|
|
or a document (i.e. an object with an `_id` or `_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const db = new Database();
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
await collection.import([
|
|
['_key', '_from', '_to'],
|
|
['x', 'vertices/a', 'vertices/b'],
|
|
['y', 'vertices/a', 'vertices/c'],
|
|
['z', 'vertices/d', 'vertices/a']
|
|
]);
|
|
const edges = await collection.edges('vertices/a');
|
|
assert.equal(edges.length, 3);
|
|
assert.deepEqual(edges.map(edge => edge._key), ['x', 'y', 'z']);
|
|
```
|
|
|
|
## graphEdgeCollection.inEdges
|
|
|
|
`async graphEdgeCollection.inEdges(documentHandle): Array<Object>`
|
|
|
|
Retrieves a list of all incoming edges of the document with the given
|
|
_documentHandle_.
|
|
|
|
**Arguments**
|
|
|
|
* **documentHandle**: `string`
|
|
|
|
The handle of the document to retrieve the edges of. This can be either the
|
|
`_id` of a document in the database, the `_key` of an edge in the collection,
|
|
or a document (i.e. an object with an `_id` or `_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const db = new Database();
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
await collection.import([
|
|
['_key', '_from', '_to'],
|
|
['x', 'vertices/a', 'vertices/b'],
|
|
['y', 'vertices/a', 'vertices/c'],
|
|
['z', 'vertices/d', 'vertices/a']
|
|
]);
|
|
const edges = await collection.inEdges('vertices/a');
|
|
assert.equal(edges.length, 1);
|
|
assert.equal(edges[0]._key, 'z');
|
|
```
|
|
|
|
## graphEdgeCollection.outEdges
|
|
|
|
`async graphEdgeCollection.outEdges(documentHandle): Array<Object>`
|
|
|
|
Retrieves a list of all outgoing edges of the document with the given
|
|
_documentHandle_.
|
|
|
|
**Arguments**
|
|
|
|
* **documentHandle**: `string`
|
|
|
|
The handle of the document to retrieve the edges of. This can be either the
|
|
`_id` of a document in the database, the `_key` of an edge in the collection,
|
|
or a document (i.e. an object with an `_id` or `_key` property).
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const db = new Database();
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
await collection.import([
|
|
['_key', '_from', '_to'],
|
|
['x', 'vertices/a', 'vertices/b'],
|
|
['y', 'vertices/a', 'vertices/c'],
|
|
['z', 'vertices/d', 'vertices/a']
|
|
]);
|
|
const edges = await collection.outEdges('vertices/a');
|
|
assert.equal(edges.length, 2);
|
|
assert.deepEqual(edges.map(edge => edge._key), ['x', 'y']);
|
|
```
|
|
|
|
## graphEdgeCollection.traversal
|
|
|
|
`async graphEdgeCollection.traversal(startVertex, opts): Object`
|
|
|
|
Performs a traversal starting from the given _startVertex_ and following edges
|
|
contained in this edge collection.
|
|
|
|
**Arguments**
|
|
|
|
* **startVertex**: `string`
|
|
|
|
The handle of the start vertex. This can be either the `_id` of a document in
|
|
the database, the `_key` of an edge in the collection, or a document (i.e. an
|
|
object with an `_id` or `_key` property).
|
|
|
|
* **opts**: `Object`
|
|
|
|
See
|
|
[the HTTP API documentation](../../../..//HTTP/Traversal/index.html)
|
|
for details on the additional arguments.
|
|
|
|
Please note that while _opts.filter_, _opts.visitor_, _opts.init_,
|
|
_opts.expander_ and _opts.sort_ should be strings evaluating to well-formed
|
|
JavaScript code, it's not possible to pass in JavaScript functions directly
|
|
because the code needs to be evaluated on the server and will be transmitted
|
|
in plain text.
|
|
|
|
**Examples**
|
|
|
|
```js
|
|
const db = new Database();
|
|
const graph = db.graph('some-graph');
|
|
const collection = graph.edgeCollection('edges');
|
|
await collection.import([
|
|
['_key', '_from', '_to'],
|
|
['x', 'vertices/a', 'vertices/b'],
|
|
['y', 'vertices/b', 'vertices/c'],
|
|
['z', 'vertices/c', 'vertices/d']
|
|
]);
|
|
const result = await collection.traversal('vertices/a', {
|
|
direction: 'outbound',
|
|
visitor: 'result.vertices.push(vertex._key);',
|
|
init: 'result.vertices = [];'
|
|
});
|
|
assert.deepEqual(result.vertices, ['a', 'b', 'c', 'd']);
|
|
```
|