seraph

v0.15.3

Published

2 years ago

A thin and familiar layer between node and neo4j's REST api.

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jonpacker

maghoff

Seraph.js

A terse & familiar binding to the Neo4j REST API that is idiomatic to node.js.

Install

npm install seraph

Quick Example

var db = require("seraph")("http://localhost:7474");

db.save({ name: "Test-Man", age: 40 }, function(err, node) {
  if (err) throw err;
  console.log("Test-Man inserted.");

  db.delete(node, function(err) {
    if (err) throw err;
    console.log("Test-Man away!");
  });
});

Documentation

Initialization

seraph - initialize the seraph client
changePassword - change the db user's password

Generic Operations

query - perform a cypher query and parse the results
queryRaw - perform a cypher query and return unparsed results

API Communication Operations

operation - create a representation of a REST API call
call - take an operation and call it
batch - perform a series of atomic operations with one api call.

Node Operations

save (node.save) - create or update a node
read (node.read) - read a node
find (node.find) - find a node using a predicate
delete (node.delete) - delete a node
relate (node.relate) - relate two nodes
relationships (node.relationships) - read the relationships of a node
legacyindex (node.legacyindex) - add a node to a legacy index
label (node.label) - add a label to a node
removeLabel (node.removeLabel) - remove a label from a node
nodesWithLabel (node.nodesWithLabel) - fetch all nodes with a label
readLabels (node.readLabels) - read the labels of a node or all available labels.

Relationship Operations

rel.create - create a relationship
rel.update - update the properties of a relationship
rel.read - read a relationship
rel.delete - delete a relationship

Constraint operations

constraints.list - list constraints
constraints.uniqueness.create - create a uniqueness constraint
constraints.uniqueness.createIfNone - create a uniqueness constraint if it doesn't already exist
constraints.uniqueness.list - list uniqueness constraints
constraints.uniqueness.drop - drop a uniqueness constraint

Indexing operations

index.create - create an index on a label and property name
index.createIfNone - create an index or return the old one
index.list - read out the indexes for a label
index.drop - drop an index

Legacy Index Operations

legacyindex.create - create an index
legacyindex.add - add a nodes/rels to an index
legacyindex.read - read nodes/rels from an index
legacyindex.remove - remove nodes/rels from an index
legacyindex.delete - delete an index
legacyindex.getOrSaveUnique - get or save a node using an index for uniqueness
legacyindex.saveUniqueOrFail - save a node using an index to enforce uniqueness

Compatibility

Seraph ~0.15 has been tested with with Neo4j 3.

Testing

You can test Seraph simply by running npm test. It will spin up its own neo4j instance for testing. Note that the first time you run your tests (or change neo4j version), a new version of neo4j will need to be downloaded. That can, of course, take a little time.

Initialization

seraph([server|options])

Creates and returns the Seraph instance. If no parameters are given, assumes the Neo4J REST API is running locally at the default location http://localhost:7474/db/data.

Arguments

options: an options object. You can use the following options:
- server (default = "http://localhost:7474"): the server to connect to (with protocol and port, not path).
- endpoint (default = "/db/data"): the path to Neo4j's rest API. You can leave this as the default if you have not changed it yourself in the neo4j settings.
- user (default = "neo4j"): the username to authenticate with.
- pass (default = "neo4j"): the password to authenticate with.
- id (default = "id"): the name of the attribute seraph will add to new nodes when they are created and that it will use to find nodes when performing updates with node.save and the like.
- agent (default = null): the http agent for requests to neo4j server. The same can be used for keep-alive connections to server. Can use agentkeepalive module to create a keep-alive agent. It's a recommended option for high performance and low latency client.
- xstream (default = false): if true, passes new X-Stream option to neo4j server. It's a recommended option for high performance and low latency client.
server (string) - Short form to specify server parameter only. "http://localhost:4747" is equivalent to { server: "http://localhost:4747" }.

Note that as of Neo4j 2.2.0, user authentication is required. You will not be able to access resources before supplying a username or password that is not the default. You can change the password using seraph#changePassword.

Example

// To http://localhost:7474/db/data with user "local" and pass "test"
var dbLocal = require("seraph")({
  user: 'local',
  pass: 'test'
});

// To http://example.com:53280/neo with user "root" and pass "jf8%kLs#!"
var dbRemote = require("seraph")({ server: "http://example.com:53280",
                                   endpoint: "/neo",
                                   user: "root",
                                   pass: "jf8%kLs#!" });

// Copy node#13 from remote server
dbRemote.read({ id: 13 }, function(err, node) {
  if (err) throw err;
  delete node.id; // copy instead of overwriting local node#13
  dbLocal.save(node, function(err, nodeL) {
    if (err) throw err;
    console.log("Copied remote node#13 to " +
                "local node#" + nodeL.id.toString() + ".");
  });
});

changePassword(newPassword, callback)

Change's the current database user's password. This will automatically update seraph's options to contain the new password if it is successful

Arguments

newPassword (string) - the new password to set.
callback (function(err){}) - callback to call when the password has been changed.

Example

// connect to a local neo4j instance with default settings (user/pass is "neo4j" by default).
var db = require("seraph")();
db.changePassword('b2(jk:4@#', function(err) {
  //password is now changed, and `db`'s options have been updated with the new password
});

Generic Operations

query(query, [params,] callback), queryRaw(query, [params,] callback)

queryRaw performs a cypher query and returns the results directly from the REST API.
query performs a cypher query and map the columns and results together.

Note: if you're performing large queries it may be advantageous to use queryRaw, since query attempts to infer whole nodes and relationships that are returned (in order to transform them into a nicer format).

Arguments

query - Cypher query as a format string.
params (optional, default={}). Replace {key} parts in query string. See cypher documentation for details. note that if you want to send a list of ids as a parameter, you should send them as an array, rather than a string representing them ([2,3] rather than "2,3").
callback - (err, result). Result is an array of objects.

Example

Given database:

{ name: 'Jon', age: 23, id: 1 }
{ name: 'Neil', age: 60, id: 2 }
{ name: 'Katie', age: 29, id: 3 }
// 1 --knows--> 2
// 1 --knows--> 3

Return all people Jon knows:

var cypher = "START x = node({id}) "
           + "MATCH x -[r]-> n "
           + "RETURN n "
           + "ORDER BY n.name";

db.query(cypher, {id: 1}, function(err, result) {
  if (err) throw err;
  assert.deepEqual(result, [
    { name: 'Katie', age: 29, id: 3 },
    { name: 'Neil', age: 60, id: 2 }
  ]);
};

db.queryRaw(cypher, {id: 3}, function(err, result) {
  if (err) throw err;
  // result contains the raw response from neo4j's rest API. See
  // http://docs.neo4j.org/chunked/milestone/rest-api-cypher.html
  // for more info
});

operation(path, [method='get/post'], [data])

Create an operation object that will be passed to call.

Arguments

path - the path fragment of the request URL with no leading slash.
method (optional, default='GET'|'POST') - the HTTP method to use. When data is an object, method defaults to 'POST'. Otherwise, method defaults to GET.
data (optional) - an object to send to the server with the request.

Example

var operation = db.operation('node/4285/properties', 'PUT', { name: 'Jon' });
db.call(operation, function(err) {
  if (!err) console.log('Set `name` to `Jon` on node 4285!');
});

call(operation, callback)

Perform an HTTP request to the server.

If the body is some JSON, it is parsed and passed to the callback.If the status code is not in the 200's, an error is passed to the callback.

Arguments

operation - an operation created by operation that specifies what to request from the server
callback - function(err, result, response). result is the JSON parsed body from the server (otherwise empty). response is the response object from the request.

Example

var operation = db.operation('node/4285/properties');
db.call(operation, function(err, properties) {
  if (err) throw err;
  // `properties` is an object containing the properties from node 4285
});

Batching/transactions - `batch([operations, callback])`

Batching provides a method of performing a series of operations atomically. You could also call it a transaction. It has the added benefit of being performed all in a single call to the neo4j api, which theoretically should result in improved performance when performing more than one operation at the same time.

When you create a batch, you're given a new seraph object to use. All calls to this object will be added to the batch. Note that once a batch is committed, you should no longer use this object.

How do I use it?

There's two ways. You can do the whole thing asynchronously, and commit the transaction whenever you want, or you can do it synchronously, and have the transaction committed for you as soon as your function is finished running. Here's a couple of examples of performing the same operations with batch synchronously and asynchronously:

Asynchronously

var txn = db.batch();

txn.save({ title: 'Kaikki Askeleet' });
txn.save({ title: 'Sinä Nukut Siinä' });
txn.save({ title: 'Pohjanmaa' });

txn.commit(function(err, results) {
  /* results -> [{ id: 1, title: 'Kaikki Askeleet' },
                 { id: 2, title: 'Sinä Nukut Siinä' },
                 { id: 3, title: 'Pohjanmaa' }] */
});

Synchronously

Note - it's only the creation of operations that is synchronous. The actual API call is asynchronous still, of course.

db.batch(function(txn) {
  txn.save({ title: 'Kaikki Askeleet' });
  txn.save({ title: 'Sinä Nukut Siinä' });
  txn.save({ title: 'Pohjanmaa' });
}, function(err, results) {
  /* results -> [{ id: 1, title: 'Kaikki Askeleet' },
                 { id: 2, title: 'Sinä Nukut Siinä' },
                 { id: 3, title: 'Pohjanmaa' }] */
});

What happens to my callbacks?

You can still pass callbacks to operations on a batch transaction. They will perform as you expect, but they will not be called until after the batch has been committed. Here's an example of using callbacks as normal:

var txn = db.batch();

txn.save({ title: 'Marmoritaivas' }, function(err, node) {
  // this code is not reached until `txn.commit` is called
  // node -> { id: 1, title: 'Marmoritaivas' }
});

txn.commit();

Can I reference newly created nodes?

Yes! Calling, for example, node.save will synchronously return a special object which you can use to refer to that newly created node within the batch.

For example, this is perfectly valid in the context of a batch transaction:

var txn = db.batch();

var singer = txn.save({name: 'Johanna Kurkela'});
var album = txn.save({title: 'Kauriinsilmät', year: 2008});
var performance = txn.relate(singer, 'performs_on', album, {role: 'Primary Artist'});
txn.rel.legacyindex('performances', performance, 'year', '2008');

txn.commit(function(err, results) {});

I didn't use any callbacks. How can I find my results when the batch is done?

Each function you call on the batch object will return a special object that you can use to refer to that call's results once that batch is finished (in addition to the intra-batch referencing feature mentioned above). The best way to demonstrate this is by example:

var txn = db.batch();

var album = txn.save({title: 'Hetki Hiljaa'});
var songs = txn.save([
  { title: 'Olen Sinussa', length: 248 },
  { title: 'Juurrun Tähän Ikävään', length: 271 }
]);
// note we can also use `songs` to reference the node that will be created
txn.relate(album, 'has_song', songs[0], { trackNumber: 1 });
txn.relate(album, 'has_song', songs[1], { trackNumber: 3 });

txn.commit(function(err, results) {
  var album = results[album]; // album -> { title: 'Hetki Hiljaa', id: 1 }
  var tracks = results[songs];
  /* tracks -> [{ title: 'Olen Sinussa', length: 248, id: 2 },
                { title: 'Juurrun Tähän Ikävään', length: 271, id: 3}] */
});

What happens if one of the operations fails?

Then no changes are made. Neo4j's batch transactions are atomic, so if one operation fails, then no changes to the database are made. Neo4j's own documentation has the following to say:

This service is transactional. If any of the operations performed fails (returns a non-2xx HTTP status code), the transaction will be rolled back and all changes will be undone.

Can I nest batches?

No, as of now we don't support nesting batches as it tends to confuse the intra-batch referencing functionality. To enforce this, you'll find that the seraph-like object returned by db.batch() has no .batch function itself.

How can I tell if this `db` object is a batch operation?

Like so:

// db.isBatch -> undefined
var txn = db.batch();
// txn.isBatch -> true
if (txn.isBatch) // Woo! I'm in a batch.

Node Operations

save(object, [label,]|[key, value,] callback)

Aliases: node.save

Create or update a node. If object has an id property, the node with that id is updated. Otherwise, a new node is created. Returns the newly created/updated node to the callback.

** Note: using node.save with a label does not work in a batch. If you want to create a node with label in a batch, you should call node.save without a label, followed by node.label with a reference to the created node. **

Arguments

node - an object to create or update
label - a label to label this node with. this is performed atomically, so if labelling the node fails, the node is not saved/updated. supplying label is exclusive with key and value. You may either specify a label, or a key and a value, but all three. ** Note: using node.save with a label does not work in a batch. If you want to create a node with label in a batch, you should call node.save without a label, followed by node.label with a reference to the created node. **
key, value (optional) - a property key and a value to update it with. This allows you to only update a single property of the node, without touching any others. If key is specified, value must also be.
callback - function(err, node). node is the newly saved or updated node. If a create was performed, node will now have an id property. The returned object is not the same reference as the passed object (the passed object will never be altered).

Example

** Creating and updating a node **

// Create a node
db.save({ name: 'Jon', age: 22, likes: 'Beer' }, function(err, node) {
  console.log(node); // -> { name: 'Jon', age: 22, likes: 'Beer', id: 1 }
  
  // Update it
  delete node.likes;
  node.age++;
  db.save(node, function(err, node) {
    console.log(node); // -> { name: 'Jon', age: 23, id: 1 }
  });
});

** Creating a node with a label **

db.save({ name: 'Jon' }, 'Person', function(err, node) {
  
});

** Update a single property on a node **

db.save({ name: 'Jon', age: 23 }, 'Person', function(err, node) {
  db.save(node, 'age', 24, function(err) {
  });
});

read(id|object, [property,] callback)

Aliases: node.read

Read a node.

Note: If the node doesn't exist, Neo4j will return an exception. You can check if this is indicating that your node doesn't exist because err.statusCode will equal 404. This is inconsistent with behaviour of node.legacyindex.read, but it is justified because the Neo4j REST api behaviour is inconsistent in this way as well.

Arguments

id | object - either the id of the node to read, or an object containing an id property of the node to read.
property (optional) - the name of the property to read. if this is specified, only the value of this property on the object is returned.
callback - function(err, node). node is an object containing the properties of the node with the given id.

Example

db.save({ make: 'Citroen', model: 'DS4' }, function(err, node) {
  db.read(node.id, function(err, node) {
    console.log(node) // -> { make: 'Citroen', model: 'DS4', id: 1 }
  });
});

delete(id|object, [force | property], [callback])

Aliases: node.delete

Delete a node.

Arguments

id | object - either the id of the node to delete, or an object containing an id property of the node to delete.
force (optional - default = false) - if truthy, will delete all the node's relations prior to deleting the node.
property (optional) - if specified, delete only the property with this name on the object. note that you can either specify property or force, not both, as force is meaningless when deleting a property
callback - function(err). if err is falsy, the node has been deleted.

Example

db.save({ name: 'Jon' }, function(err, node) {
  db.delete(node, function(err) {
    if (!err) console.log('Jon has been deleted!');
  });
});

find(predicate, [any, [label,] callback)

Aliases: node.find

Perform a query based on a predicate. The predicate is translated to a cypher query.

Arguments

predicate - Partially defined object. Will return elements which match the defined attributes of predicate.
any (optional, default=false) - If true, elements need only match on one attribute. If false, elements must match on all attributes.
label (optional, default=null) - Find only nodes with the given label. (neo4j docs on labels)
callback - function(err, results) - results is an array of the resulting nodes.

Example

Given database content:

{ name: 'Jon'    , age: 23, australian: true  }
{ name: 'Neil'   , age: 60, australian: true  }
{ name: 'Belinda', age: 26, australian: false }
{ name: 'Katie'  , age: 29, australian: true  }

Retrieve all australians:

var predicate = { australian: true };
var people = db.find(predicate, function (err, people) {
    if (err) throw err;
    assert.equals(3, people.length);
});

relationships(id|object, [direction, [type,]] callback)

*Aliases: node.relationships

Read the relationships involving the specified node.

Arguments

id | object - either the id of a node, or an object containing an id property of a node.
direction ('all'|'in'|'out') (optional unless type is passed, default='all') - the direction of relationships to read.
type (optional, default='' (match all relationships)) - the relationship type to find
callback - function(err, relationships) - relationships is an array of the matching relationships

Example

db.relationships(452, 'out', 'knows', function(err, relationships) {
  // relationships = all outgoing `knows` relationships from node 452
});

label(id|object(s), label(s), [replace,] callback)

Aliases: node.label

Add a label to a node.

Arguments

id|object(s) - either the id of the node to label, or an object containing an id property of the node to label. can be an array of objects/ids.
label(s) - the label(s) to apply. can be an array of labels.
replace (optional) - if set to true, this label will replace any previous labels.
callback - function(err). if err is falsy, the operation succeeded.

Example

db.save({ make: 'Citroen', model: 'DS4' }, function(err, node) {
  db.label(node, ['Car', 'Hatchback'], function(err) {
    // `node` is now labelled with "Car" and "Hatchback"!
  });
});

removeLabel(id|object(s), label, callback)

Aliases: node.removeLabel

Remove a label from a node.

Arguments

id|object(s) - either the id of the node to delabel, or an object containing an id property of the node to delabel. can be an array of objects/ids.
label - the label to remove. cannot be an array.
callback - function(err). if err is falsy, the operation succeeded.

Example

db.save({ make: 'Citroen', model: 'DS4' }, function(err, node) {
  db.label(node, ['Car', 'Hatchback'], function(err) {
    // `node` is now labelled with "Car" and "Hatchback"!
    db.removeLabel(node, 'Hatchback', function(err) {
      // `node` is now only labelled with "Car".
    });
  });
});

nodesWithLabel(label, callback)

Aliases: node.nodesWithLabel

Fetch all of the nodes that are labelled with a specific label.

Arguments

label - the label.
callback - function(err, results). results is always an array (assuming no error), containing the nodes that were labelled with label. if no nodes were labelled with label, results is an empty array.

Example

db.save({ make: 'Citroen', model: 'DS4' }, function(err, node) {
  db.label(node, ['Car', 'Hatchback'], function(err) {
    db.nodesWithLabel('Car', function(err, results) {
      results[0].model // -> 'DS4'
    });
  });
});

readLabels([node(s),] callback)

Aliases: node.readLabels

Read the labels of a node, or all labels in the database.

Arguments

node(s) (optional) - the node to return the labels of. if not specified, every label in the database is returned. can be an array of nodes.
callback - function(err, labels). labels is an array of labels.

Example

db.save({ make: 'Citroen', model: 'DS4' }, function(err, node) {
  db.label(node, ['Car', 'Hatchback'], function(err) {
    db.readLabels(node, function(err, labels) {
      //labels -> ['Car', 'Hatchback']
    });
  });
});

Relationship Operations

rel.create(firstId|firstObj, type, secondId|secondobj, [properties], callback)

Aliases: relate, node.relate

Create a relationship between two nodes.

Arguments

firstId | firstObject - id of the start node or an object with an id property for the start node
type - the name of the relationship
secondId | secondObject - id of the end node or an object with an id property for the end node
properties (optional, default={}) - properties of the relationship
callback - function(err, relationship) - relationship is the newly created relationship

Example

db.relate(1, 'knows', 2, { for: '2 months' }, function(err, relationship) {
  assert.deepEqual(relationship, {
    start: 1,
    end: 2,
    type: 'knows',
    properties: { for: '2 months' },
    id: 1
  });
});

rel.update(relationship, [key, value,] callback)

Update the properties of a relationship. Note that you cannot use this method to update the base properties of the relationship (start, end, type) - in order to do that you'll need to delete the old relationship and create a new one.

Arguments

relationship - the relationship object with some changed properties
key, value (optional) - if a key and value is specified, only the property with that key will be updated. the rest of the object will not be touched.
callback - function(err). if err is falsy, the update succeeded.

Example

var props = { for: '2 months', location: 'Bergen' };

db.rel.create(1, 'knows', 2, props, function(err, relationship) {
  delete relationship.properties.location;
  relationship.properties.for = '3 months';
  db.rel.update(relationship, function(err) {
    // properties on this relationship in the database are now equal to
    // { for: '3 months' }
  });
});

rel.read(object|id, callback)

Read a relationship.

Arguments

object | id - the id of the relationship to read or an object with an id property of the relationship to read.
callback - function(err, relationship). relationship is an object representing the read relationship.

Example

db.rel.create(1, 'knows', 2, { for: '2 months' }, function(err, newRelationship) {
  db.rel.read(newRelationship.id, function(err, readRelationship) {
    assert.deepEqual(newRelationship, readRelationship);
    assert.deepEqual(readRelationship, {
      start: 1,
      end: 2,
      type: 'knows',
      id: 1,
      properties: { for: '2 months' }
    });
  });
});

rel.delete(object|id, [callback])

Delete a relationship.

Arguments

object | id - the id of the relationship to delete or an object with an id property of the relationship to delete.
callback - function(err). If err is falsy, the relationship has been deleted.

Example

db.rel.create(1, 'knows', 2, { for: '2 months' }, function(err, rel) {
  db.rel.delete(rel.id, function(err) {
    if (!err) console.log("Relationship was deleted");
  });
});

Constraints Operations

constraints.list([label,] callback)

List all constraints, or optionally all constraints for a label.

Arguments

label (optional) - the label to list constraints for
callback - function(err, constraints). constraints is an array of constraint objects. For example, [{type:'UNIQUENESS', label:'Person', property_keys['name']}]

Example

db.constraints.list('Person', function(err, constraints) {
  console.log(constraints); 
  // -> [{ type: 'UNIQUENESS', label: 'Person', property_keys: ['name'] }]
});

constraints.uniqueness.list(label, [key,] callback)

List all uniqueness constraints, or optionally fetch a uniqueness constraint for key.

Arguments

label - the label to list uniqueness constraints for
key (optional) - if specified, retrieve any uniqueness constraint for this property key.
callback - function(err, constraints). constraints is an array of constraint objects. For example, [{type:'UNIQUENESS', label:'Person', property_keys: ['name']}]. If none existed, it is an empty array.

Example

db.constraints.uniqueness.list('Person', 'name', function(err, constraints) {
  console.log(constraints); 
  // -> [{ type: 'UNIQUENESS', label: 'Person',  property_keys: ['name'] }]
});

constraints.uniqueness.create(label, key, callback)

Create a uniqueness constraint on the given label. Any node labelled with label will be constrained to having a unique value for the given key. If it doesn't, attempting to label that node with label will return an error (unfortunately due to the way neo4j handles these errors, the statusCode is 400 instead of 409, but you can check with err.neo4jCause.exception == 'ConstraintViolationException'.

Arguments

label - the label to create a uniqueness constraint for
key - the key that should be unique on nodes labelled with label
callback - function(err, constraint). constraint is a constraint object representing the constraint that was created, e.g. [{type:'UNIQUENESS', label:'Person', property_keys['name']}]. If the constraint already existed, err.statusCode == 409.

Example

// any node labelled Person should have a unique `name`
db.constraints.uniqueness.create('Person', 'name', function(err, constraint) {
  console.log(constraint); 
  // -> { type: 'UNIQUENESS', label: 'Person', property_keys: ['name'] }
});

constraints.uniqueness.createIfNone(label, key, callback)

Create a uniqueness constraint on the given label. If the constraint exists, don't return an error, just return the existing constraint.

Arguments

label - the label to create a uniqueness constraint for
key - the key that should be unique on nodes labelled with label
callback - function(err, constraint). constraint is a constraint object representing the constraint that was created, e.g. [{type:'UNIQUENESS', label:'Person', property_keys: ['name']}].

Example

// any node labelled Person should have a unique `name`
db.constraints.uniqueness.createIfNone('Person', 'name', function(err, constraint) {
  console.log(constraint); 
  // -> { type: 'UNIQUENESS', label: 'Person',  property_keys: ['name'] }
  db.constraints.uniqueness.createIfNone('Person', 'name', function(err, constraint) {
    console.log(err);
    // -> undefined
    console.log(constraint); 
    // -> { type: 'UNIQUENESS', label: 'Person',  property_keys: ['name'] }
  });
});

constraints.uniqueness.drop(label, key, callback)

Drop (remove) a uniqueness constraint.

Arguments

label - the label to remove a uniqueness constraint from
key - the key on which to remove the uniqueness constraint
callback - function(err). if err is falsy, the constraint was successfully dropped

Example

// any node labelled Person should have a unique `name`
db.constraints.uniqueness.create('Person', 'name', function(err, constraint) {
  console.log(constraint); 
  // -> { type: 'UNIQUENESS', label: 'Person',  property_keys: ['name'] }
  db.constraints.uniqueness.drop('Person', 'name', function(err) {
    console.log(err);
    // -> undefined
    // the constraint has been dropped
  });
});

Indexing Operations

For more of an overview on schema-based indexing, check out the neo4j docs on the subject.

index.create(label, key, callback)

Create an index on label with key. Note that schema-based indexes are performance-boosting only and do not imply any uniqueness constraints.

Arguments

label - the label to create an index on
key - the key to index, i.e. 'name'. Note that compound indexes are not yet supported by neo4j-2
callback - function(err, index). index is an object that reflects the index that was created, i.e. { label: 'Person', property_keys: ['name'] }. Note that if you've already created the index, you'll get a conflict error. You can check this by checking err's statusCode property. 409 indicates a conflict. You can avoid this by using index.createIfNone

Example

db.index.create('Person', 'name', function(err, index) {
  console.log(index); // -> { label: 'Person', property_keys: ['name'] }
});

index.createIfNone(label, key, callback)

Create an index on label with key. Exactly the same as index.create except it will not throw an error if it encounters a conflict.

Arguments

label - the label to create an index on
key - the key to index, i.e. 'name'. Note that compound indexes are not yet supported by neo4j-2
callback - function(err, index). index is an object that reflects the index that was created, i.e. { label: 'Person', property_keys: ['name'] }.

Example

db.index.createIfNone('Person', 'name', function(err, index) {
  console.log(index); // -> { label: 'Person', property_keys: ['name'] }
});

index.list(label, callback)

Retrieve a listing of the indexes on a label.

Arguments

label - the label to retrieve indexes for
callback - function(err, indexes). indexes is an array of objects that reflect the indexes on this label, i.e. [{ label: 'Person', property_keys: ['name'] }].

Example

db.index.list('Person', function(err, index) {
  console.log(index); // -> [ { label: 'Person', property_keys: ['name'] } ]
});

index.drop(label, key, callback)

Drop an index from a label

Arguments

label - the label to drop the index from
key - the key to drop the index from
callback - function(err). if err is falsy, the index was dropped successfully.

Example

db.index.drop('Person', 'name' function(err) {
  if (!err) console.log('Index dropped!');
});

Legacy Index Operations

Note that as of Neo4j-2.0.0 legacy indexes are no longer the preferred way to handle indexing

node.legacyindex.create(name, [config,] callback)

rel.legacyindex.create(name, [config,] callback)

Create a new legacy index. If you're using the default legacy index configuration, this method is not necessary - you can just start using the legacy index with legacyindex.add as if it already existed.

NOTE for legacy index functions: there are two different types of legacy index in neo4j - node legacy indexes and relationship legacy indexes. When you're working with node legacy indexes, you use the functions on node.legacyindex. Similarly, when you're working on relationship legacy indexes you use the functions on rel.legacyindex. Most of the functions on both of these are identical (excluding the uniqueness functions), but one acts upon node legacy indexes, and the other upon relationship legacy indexes.

Arguments

name - the name of the legacy index that is being created
config (optional, default={}) - the configuration of the legacy index. See the neo4j docs for more information.
callback - function(err). If err is falsy, the legacy index has been created.

Example

var indexConfig = { type: 'fulltext', provider: 'lucene' };
db.node.legacyindex.create('a_fulltext_index', indexConfig, function(err) {
  if (!err) console.log('a fulltext legacy index has been created!');
});

node.legacyindex.add(indexName, id|object, key, value, callback);

rel.legacyindex.add(indexName, id|object, key, value, callback);

node.legacyindex.add is aliased as node.legacyindex & legacyindex

Add a node/relationship to a legacy index.

Arguments

indexName - the name of the legacy index to add the node/relationship to.
id | object - the id of the node/relationship to add to the legacy index or an object with an id property of the node/relationship to add to the legacy index.
key - the key to index the node/relationship with
value - the value to index the node/relationship with
callback - function(err). If err is falsy, the node/relationship has been indexed.

Example

db.save({ name: 'Jon' }, function(err, node) {
  db.legacyindex('people', node, 'name', node.name, function(err) {
    if (!err) console.log('Jon has been indexed!');
  });
});

node.legacyindex.read(indexName, key, value, callback);

rel.legacyindex.read(indexName, key, value, callback);

Read the object(s) from a legacy index that match a key-value pair. See also legacyindex.readAsList.

Arguments

indexName - the legacy index to read from
key - the key to match
value - the value to match
callback - function(err, results). results is a node or relationship object (or an array of them if there was more than one) that matched the given key-value pair in the given legacy index. If nothing matched, results === false. legacyindex.readAsList is similar, but always gives results as an array, with zero, one or more elements.

Example

db.rel.legacyindex.read('friendships', 'location', 'Norway', function(err, rels) {
  // `rels` is an array of all relationships indexed in the `friendships`
  // index, with a value `Norway` for the key `location`.
});

node.legacyindex.readAsList(indexName, key, value, callback);

rel.legacyindex.readAsList(indexName, key, value, callback);

Read the object(s) from a legacy index that match a key-value pair. See also legacyindex.read.

Arguments

indexName - the legacy index to read from
key - the key to match
value - the value to match
callback - function(err, results). results is an array of node or relationship objects that matched the given key-value pair in the given legacy index. legacyindex.read is similar, but gives results as false, an object or an array of objects depending on the number of hits.

Example

db.rel.legacyindex.readAsList('friendships', 'location', 'Norway', function(err, rels) {
  // `rels` is an array of all relationships indexed in the `friendships`
  // legacy index, with a value `Norway` for the key `location`.
});

node.legacyindex.remove(indexName, id|object, [key, [value,]] callback);

rel.legacyindex.remove(indexName, id|object, [key, [value,]] callback);

Remove a node/relationship from a legacy index.

Arguments

indexName - the legacy index to remove the node/relationship from.
id | object - the id of the node/relationship to remove from the legacy index or an object with an id property of the node/relationship to remove from the legacy index.
key (optional) - the key from which to remove the node/relationship. If none is specified, every reference to the node/relationship is deleted from the legacy index.
value (optional) - the value from which to remove the node/relationship. If none is specified, every reference to the node/relationship is deleted for the given key.
callback - function(err). If err is falsy, the specified references have been removed.

Example

db.node.legacyindex.remove('people', 6821, function(err) {
  if (!err) console.log("Every reference of node 6821 has been removed from the people index");
});

db.rel.legacyindex.remove('friendships', 351, 'in', 'Australia', function(err) {
  if (!err) console.log("Relationship 351 is no longer indexed as a friendship in Australia");
})

node.legacyindex.delete(name, callback);

rel.legacyindex.delete(name, callback);

Delete a legacy index.

Arguments

name - the name of the legacy index to delete
callback - function(err). if err is falsy, the legacy index has been deleted.

Example

db.rel.legacyindex.delete('friendships', function(err) {
  if (!err) console.log('The `friendships` index has been deleted');
});

node.legacyindex.getOrSaveUnique(node, index, key, value, callback);

rel.legacyindex.getOrSaveUnique(startNode, relName, endNode, [properties,] index, key, value, callback);

Save a node or relationship, using a legacy index to enforce uniqueness. If there is already a node or relationship saved under the specified key and value in the specified index, that node or relationship will be returned.

Note that you cannot use this function to update nodes.

Arguments (node)

node - the node to save
index - the name of the legacy index in which key and value are relevant
key - the key to check or store under
value - the value to check or store under
callback - function(err, node) - returns your saved node, or the node that was referenced by the specified key and value if one already existed.

Arguments (relationship)

startNode - the start point of the relationship (object containing id or id)
relName - the name of the relationship to create
endNode - the end point of the relationship (object containing id or id)
properties (optional) - an object containing properties to store on the created relationship.
index - the name of the legacy index in which key and value are relevant
key - the key to check or store under
value - the value to check or store under
callback - function(err, rel) - returns your created relationship, or the relationship that was referenced by the specified key and value if one already existed.

Example

var tag = { name: 'finnish' };

db.node.legacyindex.getOrSaveUnique(tag, 'tags', 'name', tag.name, function(err, tag) {
  // tag == { id: 1, name: 'finnish' }

  // save another new object with the same properties
  db.node.legacyindex.getOrSaveUnique({ name: 'finnish' }, 'tags', 'name', 'finnish', function(err, newTag) {
    // newTag == { id: 1, name: 'finnish' }
    // no save was performed because there was already an object at that index
  });
});

node.legacyindex.saveUniqueOrFail(node, index, key, value, callback);

rel.legacyindex.saveUniqueOrFail(startNode, relName, endNode, [properties,] index, key, value, callback);

Arguments (node)

node - the node to save
index - the name of the legacy index in which key and value are relevant
key - the key to check or store under
value - the value to check or store under
callback - function(err, node) - returns your created node, or an err with statusCode == 409 if a node already existed at that legacy index

Arguments (relationship)

startNode - the start point of the relationship (object containing id or id)
relName - the name of the relationship to create
endNode - the end point of the relationship (object containing id or id)
properties (optional) - an object containing properties to store on the created relationship.
index - the name of the legacy index in which key and value are relevant
key - the key to check or store under
value - the value to check or store under
callback - function(err, rel) - returns your created relationship, or an err with statusCode == 409 if a relationship already existed at that legacy index

Example

var tag = { name: 'finnish' };
db.node.legacyindex.saveUniqueOrFail(tag, 'tags', 'name', tag.name, function(err, tag) {
  // tag == { id: 1, name: 'finnish' }

  // save another new object with the same properties
  db.node.legacyindex.saveUniqueOrFail({ name: 'finnish' }, 'tags', 'name', 'finnish', function(err, newTag) {
    // newTag == undefined
    // err.statusCode == 409 (conflict)
    // an error was thrown because there was already a node at that index.
  });
});

Development of Seraph is lovingly sponsored by BRIK Tekonologier AS in Bergen, Norway.

Published

Vulnerabilities

Links

Maintainers

Keywords

Readme

Seraph.js

Install

Quick Example

Documentation

Initialization

Generic Operations

API Communication Operations

Node Operations

Relationship Operations

Constraint operations

Indexing operations

Legacy Index Operations

Compatibility

Testing

Initialization

seraph([server|options])

changePassword(newPassword, callback)

Generic Operations

query(query, [params,] callback), queryRaw(query, [params,] callback)

operation(path, [method='get/post'], [data])

call(operation, callback)

Batching/transactions - batch([operations, callback])

How do I use it?

Asynchronously

Synchronously

What happens to my callbacks?

Can I reference newly created nodes?

I didn't use any callbacks. How can I find my results when the batch is done?

What happens if one of the operations fails?

Can I nest batches?

How can I tell if this db object is a batch operation?

Node Operations

save(object, [label,]|[key, value,] callback)

read(id|object, [property,] callback)

delete(id|object, [force | property], [callback])

find(predicate, [any, [label,] callback)

relationships(id|object, [direction, [type,]] callback)

label(id|object(s), label(s), [replace,] callback)

removeLabel(id|object(s), label, callback)

nodesWithLabel(label, callback)

readLabels([node(s),] callback)

Relationship Operations

rel.create(firstId|firstObj, type, secondId|secondobj, [properties], callback)

rel.update(relationship, [key, value,] callback)

rel.read(object|id, callback)

rel.delete(object|id, [callback])

Constraints Operations

constraints.list([label,] callback)

constraints.uniqueness.list(label, [key,] callback)

constraints.uniqueness.create(label, key, callback)

constraints.uniqueness.createIfNone(label, key, callback)

constraints.uniqueness.drop(label, key, callback)

Indexing Operations

index.create(label, key, callback)

index.createIfNone(label, key, callback)

index.list(label, callback)

index.drop(label, key, callback)

Legacy Index Operations

node.legacyindex.create(name, [config,] callback)

rel.legacyindex.create(name, [config,] callback)

node.legacyindex.add(indexName, id|object, key, value, callback);

rel.legacyindex.add(indexName, id|object, key, value, callback);

node.legacyindex.read(indexName, key, value, callback);

rel.legacyindex.read(indexName, key, value, callback);

node.legacyindex.readAsList(indexName, key, value, callback);

rel.legacyindex.readAsList(indexName, key, value, callback);

node.legacyindex.remove(indexName, id|object, [key, [value,]] callback);

rel.legacyindex.remove(indexName, id|object, [key, [value,]] callback);

node.legacyindex.delete(name, callback);

rel.legacyindex.delete(name, callback);

node.legacyindex.getOrSaveUnique(node, index, key, value, callback);

rel.legacyindex.getOrSaveUnique(startNode, relName, endNode, [properties,] index, key, value, callback);

node.legacyindex.saveUniqueOrFail(node, index, key, value, callback);

rel.legacyindex.saveUniqueOrFail(startNode, relName, endNode, [properties,] index, key, value, callback);

Batching/transactions - `batch([operations, callback])`

How can I tell if this `db` object is a batch operation?