TreeDB

LevelDB backend for hierarchical data.

Store

Storing an object:

var db = require('levelup')('/tmp/treedb');
var tree = require('treedb')(db);
tree.store({
  type: 'person',
  name: 'Foo Bar',
  slogan: 'hello world'
}, function(err, val) {
  console.log(val);
});
 

Output:

[ 'person', 'WkvBeQ1yB' ]

Query

Query all person types:

var path = require('path');
var db = require('levelup')('/tmp/treedb');
var tree = require(path.join(__dirname, '..'))(db);
var people = [];
tree.nodes('person') // returns a readable stream
.on('data', function(person) {
  people.push(person);
})
.on('end', function() {
  console.log(people);
});
 

Output:

[ { key: [ 'person', 'WkvBeQ1yB' ],
    value: { type: 'person', name: 'Foo Bar', slogan: 'hello world' } } ]

Methods

var tree = require('treedb')(db)

Create a new treedb from a leveldb handle db and set it to the tree handle.

tree.store(obj, parentKey, cb)

If parentKey is null, the obj that is stored will be a top level object.

• obj - object to store
• parentKey - key of the parent object of the obj
• cb - callback function that is called with function(err, obj)

var rstream = tree.nodes(type, opts)

Return a readable object stream rstream with the contents of the nodes of the given type. - type - the type of the node as a string - opts - options object - indexedField - field to sort by

var rstream = tree.children(key, opts)

tree.addIndex(type, field, cb)

tree.addSecondaryIndex(type, parentType, field, cb)

Install

npm install treedb

License

MIT