Using the Web Service

This will be a general walk-through of how to use the web service to create, import, and fetch data. First, initialise a new Neo4j database as described in the initialisation instructions. Now, restart the Neo4j server like do:

$NEO4J_HOME/bin/neo4j start

Verify that everything’s working by fetching your user profile using the following Curl command (for these examples I’ll be using my own $USER, which is mike):

curl http://localhost:7474/ehri/classes/UserProfile/mike

If all goes well you should see something like:

{
  "id" : "mike",
  "type" : "UserProfile",
  "data" : {
    "identifier" : "mike",
    "name" : "Mike Bryant"
  },
  "meta" : {
    "gid" : 22
  },
  "relationships" : {
    "lifecycleEvent" : [ {
      "relationships" : {
        "hasActioner" : [ {
          "relationships" : { },
          "data" : {
            "identifier" : "admin",
            "name" : "Admin"
          },
          "meta" : {
            "followers" : 0,
            "watching" : 0,
            "following" : 0
          },
          "id" : "admin",
          "type" : "Group"
        } ]
      },
      "data" : {
        "eventType" : "creation",
        "timestamp" : "2015-10-01T15:06:38.411+01:00"
      },
      "meta" : {
        "childCount" : 1
      },
      "id" : "a2035f24-6845-11e5-92aa-ed4cb7d1dda8",
      "type" : "SystemEvent"
    } ],
    "belongsTo" : [ {
      "relationships" : { },
      "data" : {
        "identifier" : "admin",
        "name" : "Administrators"
      },
      "meta" : {
        "childCount" : 1
      },
      "id" : "admin",
      "type" : "Group"
    } ]
  }
}

This JSON data is a type of graph. It says that:

  • The user profile has global ID mike, which is the same as the local (non-hierarchical) identifier mike
  • The profile is of type UserProfile
  • It has a belongsTo relationship to a Group item with ID admin
  • There was a SystemEvent of type creation, “actioned” (or initiated) by admin.

Assuming that worked, lets go on and create the following:

  1. a Country item (via the web service RESTful API)
  2. a Repository item via EAG XML import .de/) XML import)
  3. a DocumentaryUnit item via EAD XML import

Items 1, 2, and 3 here have a hierarchical relationship, which means that we need to create them in order, since the documentary unit item will “belong” to the repository, and the repository to the country item.

Web service usage conventions

Before we start, lets just explain a couple of conventions for using the web service. You’ll notice below that any requests that change data, e.g. POST, PUT, DELETE methods, require an X-User: $USER header. This identifier the “actioner” to the system and allows the permission system to determine if they have adequate permissions (obviously, it’s the responsibility of the client application to verify people are who they say they are, but the web service does not handle authentication, only authorisation.)

We also use the X-LogMessage header when we want to tell the system what we’re doing. This will end up as the logMessage property on the SystemEvent item associated with the change.

Creating the country

We’re going to create the country via the “RESTful” web service API. The only data we absolutely need for the country item is an ISO-3166-1 alpha-2 (2 letter) code. For now we’ll use nl, for the Netherlands.

We need to send JSON data to the web service and it needs to be in a particular format, namely an object with the following data members:

  • a type property for the “content type” of the new item
  • a data object property, containing at least the item’s mandatory properties
  • an optional relationships object attribute, for nested data members

For a country, we just need type, and data, and the only attribute that needs to be present in data is the identifier property containing our two-letter code. So the JSON data we’ll send looks like this:

{
  "type": "Country",
  "data": {
    "identifier": "nl"
  }
}

Let’s send that via CURL to the /ehri/classes/Country endpoint, using application/json as the content type:

curl -X POST \
     -H "X-User: mike" \
     -H "Content-type: application/json" \
     --data '{"type": "Country", "data": {"identifier": "nl"}}' \
     http://localhost:7474/ehri/Country

We should recieve the newly-create item as the response, with more system-created metadata:

{
  "id" : "nl",
  "data" : {
    "identifier" : "nl"
  },
  "type" : "Country",
  "relationships" : {
    "lifecycleEvent" : [ {
      "id" : "1faabf00-6903-11e5-a63f-d32c8c516fe2",
      "data" : {
        "timestamp" : "2015-10-02T13:43:04.105+01:00",
        "eventType" : "creation"
      },
      "type" : "SystemEvent",
      "relationships" : {
        "hasActioner" : [ {
          "id" : "mike",
          "data" : {
            "name" : "mike",
            "identifier" : "mike"
          },
          "type" : "UserProfile",
          "relationships" : { },
          "meta" : {
            "following" : 0,
            "followers" : 0,
            "watching" : 0
          }
        } ]
      },
      "meta" : {
        "childCount" : 1
      }
    } ]
  },
  "meta" : {
    "childCount" : 0,
    "gid" : 26
  }
}

A few things to note:

  • the system-defined global ID is the same as the local identifier property we provided, since countries are top-level items
  • there’s a creation event, actioned by us

Since the global ID is nl, we can fetch the item from the web service specifically using:

curl http://localhost:7474/ehri/classes/Country/nl

This should give the same result as when we created it.

Importing a repository via EAG

Now we’re going to create a repository inside our new country. Since repositories require somewhat more metadata to be useful, we’re going to import it via an EAG file. Download and extract the sample EAC, EAD, and EAG XML documents from the samples.tgz archive.

To import eag.xml we’re going to use the /ehri/import/eag web service method like so:

curl    -X POST \
        -H "X-User: mike" \
        -H "X-LogMessage: Testing EAG import" \
        -H "Content-type: text/xml" \
        --data @eag.xml \
        http://localhost:7474/ehri/import/eag?scope=nl

We should receive a response like so:

{"message":"Testing EAG import","updated":0,"created":1,"unchanged":0}

This tells us that we created one new item, as expected. The import endpoint is idempotent so we can run the same thing again and it’ll tell us that there were no changes.

{"message":"Testing EAG import","updated":0,"created":0,"unchanged":1}

Unfortunately, the import methods don’t tell us much about the actual items we’ve just created, so lets list all the repositories and see what we see there:

curl http://localhost:7474/ehri/classes/Repository

This gives us the somewhat more extensive data:

[
    {
        "data": {
            "identifier": "test-repository",
            "typeOfEntity": "organisation"
        },
        "id": "nl-test_repository",
        "meta": {
            "childCount": 0,
            "gid": 30,
            "watchedBy": 0
        },
        "relationships": {
            "describes": [
                {
                    "data": {
                        "accessibility": "Use public transport",
                        "creationProcess": "IMPORT",
                        "history": "Example Repository Description",
                        "holdings": "Large",
                        "identifier": "test-repository#desc",
                        "languageCode": "eng",
                        "name": "Test Repository",
                        "openingTimes": "9-5 All week",
                        "otherFormsOfName": "Test Repository - Alt Name",
                        "rulesAndConventions": "ISDIAH",
                        "typeOfEntity": "organisation"
                    },
                    "id": "nl-test_repository.eng-test_repository_desc",
                    "meta": {
                        "gid": 31
                    },
                    "relationships": {
                        "hasAddress": [
                            {
                                "data": {
                                    "countryCode": "NL",
                                    "email": "[email protected]",
                                    "municipality": "A Town",
                                    "postalCode": "ABC 123",
                                    "street": "Any Street",
                                    "telephone": "12345 678910",
                                    "webpage": "www.example.com"
                                },
                                "id": "3320f8ec-6905-11e5-accc-dd70c2facf88",
                                "meta": {
                                    "gid": 33
                                },
                                "relationships": {},
                                "type": "Address"
                            }
                        ],
                        "hasUnknownProperty": [
                            {
                                "data": {
                                    "eag_archguide_desc_email_": "Email",
                                    "eag_archguide_desc_webpage_": "Website",
                                    "eag_archguide_identity_repositorid_": "test"
                                },
                                "id": "3320f8ee-6905-11e5-accc-dd70c2facf88",
                                "meta": {
                                    "gid": 32
                                },
                                "relationships": {},
                                "type": "UnknownProperty"
                            }
                        ]
                    },
                    "type": "RepositoryDescription"
                }
            ],
            "hasCountry": [
                {
                    "data": {
                        "identifier": "nl"
                    },
                    "id": "nl",
                    "meta": {
                        "childCount": 1
                    },
                    "relationships": {},
                    "type": "Country"
                }
            ],
            "lifecycleEvent": [
                {
                    "data": {
                        "eventType": "ingest",
                        "timestamp": "2015-10-02T13:57:55.686+01:00"
                    },
                    "id": "334e98a2-6905-11e5-accc-dd70c2facf88",
                    "meta": {
                        "childCount": 1
                    },
                    "relationships": {
                        "hasActioner": [
                            {
                                "data": {
                                    "identifier": "mike",
                                    "name": "mike"
                                },
                                "id": "mike",
                                "meta": {
                                    "followers": 0,
                                    "following": 0,
                                    "watching": 0
                                },
                                "relationships": {},
                                "type": "UserProfile"
                            }
                        ]
                    },
                    "type": "SystemEvent"
                }
            ]
        },
        "type": "Repository"
    }
]

We have a JSON list with one item (as expected, since we’ve only created one repository). A few things to note:

  • this time the lifecycleEvent is ingest, again with hasActioner “mike”.
  • there is a hasCountry relationship pointing to our nl country
  • there is a describes relationship to a RepositoryDescription item with (default) languageCode value eng, that contains the bulk of the data in our EAG file.
  • the system ID is nl-test_repository, and the identifier value is test_repository.

We can fetch the item directly using its ID via:

curl http://localhost:7474/ehri/classes/Repository/nl-test_repository

Importing a documentary unit via EAD

Importing EAD is much the same process, only this time we use the /ehri/import/ead method and the repository (with ID nl-test_repository) is the scope item that we are importing into:

curl    -X POST \
        -H "X-User: mike" \
        -H "X-LogMessage: Testing EAD import" \
        -H "Content-type: text/xml" \
        --data @ead.xml \
        http://localhost:7474/ehri/import/ead?scope=nl-test_repository

Run this and again we get an import log like so:

{"message":"Testing EAD import","updated":0,"created":1,"unchanged":0}

Running GET on the /ehri/classes/DocumentaryUnit method lists the units in the system, giving us this rather verbose output:

[
    {
        "data": {
            "identifier": "test-doc"
        },
        "id": "nl-test_repository-test_doc",
        "meta": {
            "childCount": 0,
            "gid": 37,
            "watchedBy": 0
        },
        "relationships": {
            "describes": [
                {
                    "data": {
                        "creationProcess": "IMPORT",
                        "extentAndMedium": "167 files",
                        "languageCode": "eng",
                        "languageOfMaterial": [
                            "eng",
                            "fra",
                            "deu",
                            "heb",
                            "ron",
                            "yid"
                        ],
                        "levelOfDescription": "collection",
                        "name": "Test EAD Item",
                        "scopeAndContent": "This is some test scope and content.",
                        "sourceFileId": "C00001#ENG"
                    },
                    "id": "nl-test_repository-test_doc.eng",
                    "meta": {
                        "gid": 38
                    },
                    "relationships": {
                        "hasDate": [
                            {
                                "data": {
                                    "description": "1924-1-1 - 1947-12-31",
                                    "endDate": "1947-12-31",
                                    "startDate": "1924-01-01"
                                },
                                "id": "de1f5c77-6908-11e5-8ffa-0da85690eef2",
                                "meta": {
                                    "gid": 42
                                },
                                "relationships": {},
                                "type": "DatePeriod"
                            },
                            {
                                "data": {
                                    "description": "1943-1-1",
                                    "endDate": "1943-01-31",
                                    "startDate": "1943-01-01"
                                },
                                "id": "de1f5c79-6908-11e5-8ffa-0da85690eef2",
                                "meta": {
                                    "gid": 43
                                },
                                "relationships": {},
                                "type": "DatePeriod"
                            }
                        ],
                        "hasUnknownProperty": [
                            {
                                "data": {
                                    "ead_archdesc_did_langmaterial_language_": [
                                        "English",
                                        "French",
                                        "German",
                                        "Hebrew",
                                        "Romanian",
                                        "Yiddish"
                                    ],
                                    "ead_archdesc_did_repository_address_addressline_": [
                                        "Test Address 1",
                                        "Test Address 2"
                                    ],
                                    "ead_archdesc_did_repository_corpname_": "Test Corportate Body"
                                },
                                "id": "de1f5c75-6908-11e5-8ffa-0da85690eef2",
                                "meta": {
                                    "gid": 41
                                },
                                "relationships": {},
                                "type": "UnknownProperty"
                            }
                        ],
                        "relatesTo": [
                            {
                                "data": {
                                    "name": "Test Name",
                                    "type": "creatorAccess"
                                },
                                "id": "de1f5c73-6908-11e5-8ffa-0da85690eef2",
                                "meta": {
                                    "gid": 40
                                },
                                "relationships": {},
                                "type": "AccessPoint"
                            },
                            {
                                "data": {
                                    "name": "Test Corporate Body",
                                    "type": "subjectAccess"
                                },
                                "id": "de1f5c71-6908-11e5-8ffa-0da85690eef2",
                                "meta": {
                                    "gid": 39
                                },
                                "relationships": {},
                                "type": "AccessPoint"
                            }
                        ]
                    },
                    "type": "DocumentaryUnitDescription"
                }
            ],
            "heldBy": [
                {
                    "data": {
                        "identifier": "test-repository"
                    },
                    "id": "nl-test_repository",
                    "meta": {
                        "childCount": 1,
                        "watchedBy": 0
                    },
                    "relationships": {
                        "describes": [
                            {
                                "data": {
                                    "languageCode": "eng",
                                    "name": "Test Repository"
                                },
                                "id": "nl-test_repository.eng-test_repository_desc",
                                "relationships": {},
                                "type": "RepositoryDescription"
                            }
                        ],
                        "hasCountry": [
                            {
                                "data": {
                                    "identifier": "nl"
                                },
                                "id": "nl",
                                "meta": {
                                    "childCount": 1
                                },
                                "relationships": {},
                                "type": "Country"
                            }
                        ]
                    },
                    "type": "Repository"
                }
            ],
            "lifecycleEvent": [
                {
                    "data": {
                        "eventType": "ingest",
                        "timestamp": "2015-10-02T14:24:11.166+01:00"
                    },
                    "id": "de2db45d-6908-11e5-8ffa-0da85690eef2",
                    "meta": {
                        "childCount": 1
                    },
                    "relationships": {
                        "hasActioner": [
                            {
                                "data": {
                                    "identifier": "mike",
                                    "name": "mike"
                                },
                                "id": "mike",
                                "meta": {
                                    "followers": 0,
                                    "following": 0,
                                    "watching": 0
                                },
                                "relationships": {},
                                "type": "UserProfile"
                            }
                        ]
                    },
                    "type": "SystemEvent"
                }
            ]
        },
        "type": "DocumentaryUnit"
    }
]

Again, stuff to note:

  • the generated ID is nl-test_repository-test_doc, while the identifier property is test-doc
  • the repository is present in the heldBy relationship

Additional import options

In these examples we POSTed a single XML file (with content-type text/xml) to the import methods. This is convenient for single files, but often you want to import multiple XML files at once into the same country, repository, or documentary unit (as child items.) In this case it is possible to create zip or tar archives containing those files and POST the data as content type application/octet-stream.

Another (less good) alternative when the web service server is local is to POST a file containing a list (one entry per line) of local file paths with content-type text/plain