Make specific exceptions for error conditions

[flip111]

This is an example of an exception i get

[Neoxygen\NeoClient\Exception\Neo4jException]
Neo4j Exception with code "Neo.ClientError.Schema.ConstraintViolation" and message "Node 59 already exists with label user and property "username"=[flip111]"

It would be nice to have a specific exception for this. Maybe the class can be called ConstraintViolationException. Then what i can do in the code is:

function createUser() {
  try {
    $client->sendCypherQuery('CREATE (n:user {username:"flip111"})');
  } catch (ConstraintViolationException $e) {
    // notify the user somehow the user already exist
  }
  // Other exceptions are not caught and can display a 500 Internal Server error page
}

It would require creating exception based on the exception code. (That would also require knowing all the possible exception codes, which i don't know where to find a list for)

[flip111]

Alternatively an easy improvement without have to create tons of exception classes would be to make the code available on the exception as property. Right now this information is pushed inside a string and not accesible anymore

https://github.com/neoxygen/neo4j-neoclient/blob/6028690c950c47e43bf66fac8b184d927860deb2/src/Extension/AbstractExtension.php#L94-L98

This is how the code would look like in that case:

function createUser() {
  try {
    $client->sendCypherQuery('CREATE (n:user {username:"flip111"})');
  } catch (\Neo4jException $e) {
    if ($e->getCode() === 'Neo.ClientError.Schema.ConstraintViolation') {
      // notify the user somehow the user already exist
    } else {
      throw $e;
    }
  }
  // Other exceptions are not caught and can display a 500 Internal Server error page
}

(not really sure if that getter is really needed, perhaps a simple property will do)

[ikwattro]

This is a planned stuff.

[flip111]

:+1: