Content Manipulation¶
plone.restapi does not only expose content objects via a RESTful API. The API consumer can create, read, update, and delete a content object. Those operations can be mapped to the HTTP verbs POST (Create), GET (Read), PUT (Update) and DELETE (Delete).
Manipulating resources across the network by using HTTP as an application protocol is one of core principles of the REST architectural pattern. This allows us to interact with a specific resource in a standardized way:
Verb | URL | Action |
---|---|---|
POST | /folder | Creates a new document within the folder |
GET | /folder/{document-id} | Request the current state of the document |
PATCH | /folder/{document-id} | Update the document details |
DELETE | /folder/{document-id} | Remove the document |
Creating a Resource with POST¶
To create a new resource, we send a POST request to the resource container. If we want to create a new document within an existing folder, we send a POST request to that folder:
POST /plone/folder HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
Content-Type: application/json
{
"@type": "Document",
"title": "My Document"
}
curl -i -X POST http://nohost/plone/folder -H 'Accept: application/json' -H 'Content-Type: application/json' --data-raw '{"@type": "Document", "title": "My Document"}' --user admin:secret
echo '{
"@type": "Document",
"title": "My Document"
}' | http POST http://nohost/plone/folder Accept:application/json Content-Type:application/json -a admin:secret
requests.post('http://nohost/plone/folder', headers={
'Accept': 'application/json',
'Content-Type': 'application/json',
}, json={
'@type': 'Document',
'title': 'My Document',
}, auth=('admin', 'secret'))
By setting the ‘Accept’ header, we tell the server that we would like to receive the response in the ‘application/json’ representation format.
The ‘Content-Type’ header indicates that the body uses the ‘application/json’ format.
The request body contains the minimal necessary information needed to create a document (the type and the title). You could set other properties, like “description” here as well.
Successful Response (201 Created)¶
If a resource has been created, the server responds with the 201 Created status code. The ‘Location’ header contains the URL of the newly created resource and the resource representation in the payload:
HTTP/1.1 201 Created
Content-Type: application/json
Location: http://localhost:55001/plone/folder/my-document
{
"@components": {
"actions": {
"@id": "http://localhost:55001/plone/folder/my-document/@actions"
},
"breadcrumbs": {
"@id": "http://localhost:55001/plone/folder/my-document/@breadcrumbs"
},
"navigation": {
"@id": "http://localhost:55001/plone/folder/my-document/@navigation"
},
"workflow": {
"@id": "http://localhost:55001/plone/folder/my-document/@workflow"
}
},
"@id": "http://localhost:55001/plone/folder/my-document",
"@type": "Document",
"UID": "SomeUUID000000000000000000000005",
"allow_discussion": false,
"changeNote": "",
"contributors": [],
"created": "2016-10-21T19:00:00+00:00",
"creators": [
"admin"
],
"description": "",
"effective": null,
"exclude_from_nav": false,
"expires": null,
"id": "my-document",
"is_folderish": false,
"language": "",
"layout": "document_view",
"modified": "2016-10-21T19:00:00+00:00",
"parent": {
"@id": "http://localhost:55001/plone/folder",
"@type": "Folder",
"description": "This is a folder with two documents",
"review_state": "private",
"title": "My Folder"
},
"relatedItems": [],
"review_state": "private",
"rights": "",
"subjects": [],
"table_of_contents": null,
"text": null,
"title": "My Document",
"version": "current",
"versioning_enabled": true
}
Unsuccessful Response (400 Bad Request)¶
If the resource could not be created, for instance because the title was missing in the request, the server responds with 400 Bad Request:
HTTP/1.1 400 Bad Request
Content-Type: application/json
{
'message': 'Required title field is missing'
}
The response body can contain information about why the request failed.
Unsuccessful Response (500 Internal Server Error)¶
If the server can not properly process a request, it responds with 500 Internal Server Error:
HTTP/1.1 500 Internal Server Error
Content-Type: application/json
{
'message': 'Internal Server Error'
}
The response body can contain further information such as an error trace or a link to the documentation.
Possible POST Responses¶
Possible server reponses for a POST request are:
- 201 Created (Resource has been created successfully)
- 400 Bad Request (malformed request to the service)
- 500 Internal Server Error (server fault, can not recover internally)
POST Implementation¶
A pseudo-code example of the POST implementation on the server:
try:
order = createOrder()
if order == None:
# Bad Request
response.setStatus(400)
else:
# Created
response.setStatus(201)
except:
# Internal Server Error
response.setStatus(500)
TODO: Link to the real implementation… [
Reading a Resource with GET¶
After a successful POST, we can access the resource by sending a GET request to the resource URL:
GET /plone/folder/my-document HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
curl -i http://nohost/plone/folder/my-document -H 'Accept: application/json' --user admin:secret
http http://nohost/plone/folder/my-document Accept:application/json -a admin:secret
requests.get('http://nohost/plone/folder/my-document', headers={
'Accept': 'application/json',
}, auth=('admin', 'secret'))
You can also set the include_items GET parameter to false if you don’t want to include children.
Successful Response (200 OK)¶
If a resource has been retrieved successfully, the server responds with 200 OK:
HTTP/1.1 200 OK
Content-Type: application/json
{
"@components": {
"actions": {
"@id": "http://localhost:55001/plone/folder/my-document/@actions"
},
"breadcrumbs": {
"@id": "http://localhost:55001/plone/folder/my-document/@breadcrumbs"
},
"navigation": {
"@id": "http://localhost:55001/plone/folder/my-document/@navigation"
},
"workflow": {
"@id": "http://localhost:55001/plone/folder/my-document/@workflow"
}
},
"@id": "http://localhost:55001/plone/folder/my-document",
"@type": "Document",
"UID": "SomeUUID000000000000000000000005",
"allow_discussion": false,
"changeNote": "",
"contributors": [],
"created": "2016-10-21T19:00:00+00:00",
"creators": [
"admin"
],
"description": "",
"effective": null,
"exclude_from_nav": false,
"expires": null,
"id": "my-document",
"is_folderish": false,
"language": "",
"layout": "document_view",
"modified": "2016-10-21T19:00:00+00:00",
"parent": {
"@id": "http://localhost:55001/plone/folder",
"@type": "Folder",
"description": "This is a folder with two documents",
"review_state": "private",
"title": "My Folder"
},
"relatedItems": [],
"review_state": "private",
"rights": "",
"subjects": [],
"table_of_contents": null,
"text": null,
"title": "My Document",
"version": "current",
"versioning_enabled": true
}
Note
For folderish types, collections or search results, the results will be batched if the size of the resultset exceeds the batch size. See Batching for more details on how to work with batched results.
Unsuccessful response (404 Not Found)¶
If a resource could not be found, the server will respond with 404 Not Found:
HTTP/1.1 404 Not Found
Content-Type: application/json
{
'error': 'NotFound'
}
GET Implementation¶
A pseudo-code example of the GET implementation on the server:
try:
order = getOrder()
if order == None:
# Not Found
response.setStatus(404)
else:
# OK
response.setStatus(200)
except:
# Internal Server Error
response.setStatus(500)
You can find implementation details in the plone.restapi.services.content.add.FolderPost class
GET Responses¶
Possible server reponses for a GET request are:
Updating a Resource with PATCH¶
To update an existing resource we send a PATCH request to the server. PATCH allows to provide just a subset of the resource (the values you actually want to change).
If you send the value null
for a field, the field’s content will be
deleted and the missing_value
defined for the field in the schema
will be set. Note that this is not possible if the field is required
,
and it only works for Dexterity types, not Archetypes:
PATCH /plone/folder/my-document HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
Content-Type: application/json
{
"title": "My New Document Title"
}
curl -i -X PATCH http://nohost/plone/folder/my-document -H 'Accept: application/json' -H 'Content-Type: application/json' --data-raw '{"title": "My New Document Title"}' --user admin:secret
echo '{
"title": "My New Document Title"
}' | http PATCH http://nohost/plone/folder/my-document Accept:application/json Content-Type:application/json -a admin:secret
requests.patch('http://nohost/plone/folder/my-document', headers={
'Accept': 'application/json',
'Content-Type': 'application/json',
}, json={
'title': 'My New Document Title',
}, auth=('admin', 'secret'))
Successful Response (204 No Content)¶
A successful response to a PATCH request will be indicated by a 204 No Content response by default:
HTTP/1.1 204 No Content
Successful Response (200 OK)¶
You can get the object representation by adding a Prefer header with a value of return=representation to the PATCH request. In this case, the response will be a 200 OK:
PATCH /plone/folder/my-document HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
Prefer: return=representation
Content-Type: application/json
{
"title": "My New Document Title"
}
curl -i -X PATCH http://nohost/plone/folder/my-document -H 'Accept: application/json' -H 'Content-Type: application/json' -H 'Prefer: return=representation' --data-raw '{"title": "My New Document Title"}' --user admin:secret
echo '{
"title": "My New Document Title"
}' | http PATCH http://nohost/plone/folder/my-document Accept:application/json Content-Type:application/json Prefer:return=representation -a admin:secret
requests.patch('http://nohost/plone/folder/my-document', headers={
'Accept': 'application/json',
'Content-Type': 'application/json',
'Prefer': 'return=representation',
}, json={
'title': 'My New Document Title',
}, auth=('admin', 'secret'))
HTTP/1.1 200 OK
Content-Type: application/json
{
"@components": {
"actions": {
"@id": "http://localhost:55001/plone/folder/my-document/@actions"
},
"breadcrumbs": {
"@id": "http://localhost:55001/plone/folder/my-document/@breadcrumbs"
},
"navigation": {
"@id": "http://localhost:55001/plone/folder/my-document/@navigation"
},
"workflow": {
"@id": "http://localhost:55001/plone/folder/my-document/@workflow"
}
},
"@id": "http://localhost:55001/plone/folder/my-document",
"@type": "Document",
"UID": "SomeUUID000000000000000000000005",
"allow_discussion": false,
"changeNote": "",
"contributors": [],
"created": "2016-10-21T19:00:00+00:00",
"creators": [
"admin"
],
"description": "",
"effective": null,
"exclude_from_nav": false,
"expires": null,
"id": "my-document",
"is_folderish": false,
"language": "",
"layout": "document_view",
"modified": "2016-10-21T19:00:00+00:00",
"parent": {
"@id": "http://localhost:55001/plone/folder",
"@type": "Folder",
"description": "This is a folder with two documents",
"review_state": "private",
"title": "My Folder"
},
"relatedItems": [],
"review_state": "private",
"rights": "",
"subjects": [],
"table_of_contents": null,
"text": null,
"title": "My New Document Title",
"version": "current",
"versioning_enabled": true
}
See for full specs the RFC 5789: PATCH Method for HTTP
Replacing a Resource with PUT¶
Note
PUT is not implemented yet.
To replace an existing resource we send a PUT request to the server:
TODO: Add example.
In accordance with the HTTP specification, a successful PUT will not create a new resource or produce a new URL.
PUT expects the entire resource representation to be supplied to the server, rather than just changes to the resource state. This is usually not a problem since the consumer application requested the resource representation before a PUT anyways.
When the PUT request is accepted and processed by the service, the consumer will receive a 204 No Content response (200 OK would be a valid alternative).
Successful Update (204 No Content)¶
When a resource has been updated successfully, the server sends a 204 No Content response:
TODO: Add example.
Unsuccessful Update (409 Conflict)¶
Sometimes requests fail due to incompatible changes. The response body includes additional information about the problem.
TODO: Add example.
PUT Implementation¶
A pseudo-code example of the PUT implementation on the server:
try:
order = getOrder()
if order:
try:
saveOrder()
except conflict:
response.setStatus(409)
# OK
response.setStatus(200)
else:
# Not Found
response.setStatus(404)
except:
# Internal Server Error
response.setStatus(500)
TODO: Link to the real implementation…
PUT Responses¶
Possible server reponses for a PUT request are:
POST vs. PUT¶
Difference between POST and PUT:
- Use POST to create a resource identified by a service-generated URI
- Use POST to append a resource to a collection identified by a service-generated URI
- Use PUT to overwrite a resource
This follows RFC 7231: HTTP 1.1: PUT Method.
Removing a Resource with DELETE¶
We can delete an existing resource by sending a DELETE request:
DELETE /plone/folder/my-document HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
curl -i -X DELETE http://nohost/plone/folder/my-document -H 'Accept: application/json' --user admin:secret
http DELETE http://nohost/plone/folder/my-document Accept:application/json -a admin:secret
requests.delete('http://nohost/plone/folder/my-document', headers={
'Accept': 'application/json',
}, auth=('admin', 'secret'))
A successful response will be indicated by a 204 No Content response:
HTTP/1.1 204 No Content
DELETE Implementation¶
A pseudo-code example of the DELETE implementation on the server:
try:
order = getOrder()
if order:
if can_delete(order):
# No Content
response.setStatus(204)
else:
# Not Allowed
response.setStatus(405)
else:
# Not Found
response.setStatus(404)
except:
# Internal Server Error
response.setStatus(500)
TODO: Link to the real implementation…
DELETE Responses¶
Possible responses to a delete request are:
- 204 No Content
- 404 Not Found (if the resource does not exist)
- 405 Method Not Allowed (if deleting the resource is not allowed)
- 500 Internal Server Error
Reordering sub resources¶
The resources contained within a resource can be reordered using the ordering key using a PATCH request on the container.
Use the obj_id subkey to specify which resource to reorder. The subkey delta can be ‘top’, ‘bottom’, or a negative or positive integer for moving up or down.
Reordering resources within a subset of resources can be done using the subset_ids subkey.
A response 400 BadRequest with a message ‘Client/server ordering mismatch’ will be returned if the value is not in the same order as serverside.
A response 400 BadRequest with a message ‘Content ordering is not supported by this resource’ will be returned if the container does not support ordering.
PATCH /plone/folder/my-document HTTP/1.1
Accept: application/json
Authorization: Basic YWRtaW46c2VjcmV0
Content-Type: application/json
{
"ordering": {"obj_id": "item_3", "delta": "top", "subset_ids": ["item_1", "item_3", "item5"]}
}
curl -i -X PATCH http://nohost/plone/folder/my-document -H 'Accept: application/json' -H 'Content-Type: application/json' --data-raw '{"ordering": {"delta": "top", "obj_id": "item_3", "subset_ids": ["item_1", "item_3", "item5"]}}' --user admin:secret
echo '{
"ordering": {
"delta": "top",
"obj_id": "item_3",
"subset_ids": [
"item_1",
"item_3",
"item5"
]
}
}' | http PATCH http://nohost/plone/folder/my-document Accept:application/json Content-Type:application/json -a admin:secret
requests.patch('http://nohost/plone/folder/my-document', headers={
'Accept': 'application/json',
'Content-Type': 'application/json',
}, json={
'ordering': {
'delta': 'top',
'obj_id': 'item_3',
'subset_ids': ['item_1', 'item_3', 'item5'],
},
}, auth=('admin', 'secret'))