Working with Neo4j Rest API in Swift - swift

Question

i am quite new to iOS and Swift and now i want to use Neo4j, a Graph Database for persistent saving of my data.
I know there's a Lib named Theo for connecting to the Graph Database, but i want to use the REST API. Now i am not sure how to handle the HTTP-Request in order to get data from Database to my iOS-App written in Swift?
Anyone has some helpful clues for my?
Thanks hannes

Answer 1

The Theo library that you mention is a wrapper around the Neo4j REST API. The benefit of using such a library is that it takes care of things like JSON serialization, error handling, adding the correct headers to HTTP requests, etc.
You can use Cypher with the transactional Cypher REST API endpoint using Swift like this (Note: this uses the Alamofire library for handling the HTTP request.):
import Alamofire
let cypherStatement = "CREATE (:Person {name: 'Bob'})-[:LIKES]->(pizza:Food {type: 'Pizza'})<-[:LIKES]-(:Person {name: 'William'}) WITH pizza MATCH (p:Person)-[:LIKES]->(pizz) RETURN p.name AS name"
let endpoint = "http://localhost:7474/db/data/transaction/commit"
let requestBody = [
"statements": [
[
"statement": cypherStatement
]
]
]
Alamofire.request(.POST, endpoint, parameters: requestBody, encoding: .JSON)
.responseJSON { response in
debugPrint(response)
}
Which logs:
[Request]: <NSMutableURLRequest: 0x7fafcb637320> { URL: http://localhost:7474/db/data/transaction/commit }
[Response]: <NSHTTPURLResponse: 0x7fafcb81d480> { URL: http://localhost:7474/db/data/transaction/commit } { status code: 200, headers {
"Access-Control-Allow-Origin" = "*";
"Content-Length" = 91;
"Content-Type" = "application/json";
Date = "Fri, 18 Dec 2015 19:29:41 GMT";
Server = "Jetty(9.2.z-SNAPSHOT)";
} }
[Data]: 91 bytes
[Result]: SUCCESS: {
errors = (
);
results = (
{
columns = (
name
);
data = (
{
row = (
Bob
);
},
{
row = (
William
);
}
);
}
);
}
Edit
Making the same request without using Alamofire would look like this:
let cypherStatement = "CREATE (:Person {name: 'Bob'})-[:LIKES]->(pizza:Food {type: 'Pizza'})<-[:LIKES]-(:Person {name: 'William'}) WITH pizza MATCH (p:Person)-[:LIKES]->(pizz) RETURN p.name AS name"
let endpoint = "http://localhost:7474/db/data/transaction/commit"
let requestBody = [
"statements": [
[
"statement": cypherStatement
]
]
]
guard let url = NSURL(string: endpoint) else {
print("Error")
return true
}
let request = NSMutableURLRequest(URL: url)
request.HTTPMethod = "POST"
request.addValue("application/json",forHTTPHeaderField: "Content-Type")
request.addValue("application/json",forHTTPHeaderField: "Accept")
do{
let jsonData = try NSJSONSerialization.dataWithJSONObject(requestBody, options: .PrettyPrinted)
request.HTTPBody = jsonData
let config = NSURLSessionConfiguration.defaultSessionConfiguration()
let session = NSURLSession(configuration: config)
let task = session.dataTaskWithRequest(request, completionHandler: { (data, response, error) in
let result: NSDictionary
do {
result = try NSJSONSerialization.JSONObjectWithData(data!,
options: []) as! NSDictionary
} catch {
print("error trying to convert data to JSON")
return
}
print("\(result)")
})
task.resume()
} catch let error as NSError {
print("JSON serialization error")
return true
}