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Shuffle pagination section around

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Kegan Dougal 9 years ago
parent 7bdb71b1c9
commit 07d7a3fa3a
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specification/1-client_server_api.rst
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@ -340,100 +340,6 @@ This MUST return an HTML page which can perform this authentication stage. This
page must attempt to call the JavaScript function ``window.onAuthDone`` when
the authentication has been completed.
Pagination
----------
.. NOTE::
The paths referred to in this section are not actual endpoints. They only
serve as examples to explain how pagination functions.
Pagination is the process of dividing a dataset into multiple discrete pages.
Matrix makes use of pagination to allow clients to view extremely large datasets.
These datasets are not limited to events in a room (for example clients may want
to paginate rooms in addition to events within those rooms). Regardless of *what*
is being paginated, there is a common underlying API which is used to
to give clients a consistent way of selecting subsets of a potentially changing
dataset. Requests pass in ``from``, ``to``, ``dir`` and ``limit`` parameters
which describe where to read from the stream. ``from`` and ``to`` are opaque
textual 'stream tokens' which describe the current position in the dataset.
The ``dir`` parameter is an enum representing the direction of events to return:
either ``f`` orwards or ``b`` ackwards. The response returns new ``start`` and
``end`` stream token values which can then be passed to subsequent requests to
continue pagination. Not all endpoints will make use of all the parameters
outlined here: see the specific endpoint in question for more information.
Pagination Request Query Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Query parameters:
from:
$streamtoken - The opaque token to start streaming from.
to:
$streamtoken - The opaque token to end streaming at. Typically,
clients will not know the item of data to end at, so this will usually be
omitted.
limit:
integer - An integer representing the maximum number of items to
return.
dir:
f|b - The direction to return events in. Typically this is ``b`` to paginate
backwards in time.
'START' and 'END' are placeholder values used in these examples to describe the
start and end of the dataset respectively.
Unless specified, the default pagination parameters are ``from=START``,
``to=END``, without a limit set.
For example, if an endpoint had events E1 -> E15. The client wants the last 5
events and doesn't know any previous events::
S E
|-E1-E2-E3-E4-E5-E6-E7-E8-E9-E10-E11-E12-E13-E14-E15-|
| | |
| _____| <--backwards-- |
|__________________ | | ________|
| | | |
GET /somepath?to=START&limit=5&dir=b&from=END
Returns:
E15,E14,E13,E12,E11
Another example: a public room list has rooms R1 -> R17. The client is showing 5
rooms at a time on screen, and is on page 2. They want to
now show page 3 (rooms R11 -> 15)::
S E
| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | stream token
|-R1-R2-R3-R4-R5-R6-R7-R8-R9-R10-R11-R12-R13-R14-R15-R16-R17| room
|____________| |________________|
| |
Currently |
viewing |
|
GET /roomslist?from=9&to=END&limit=5
Returns: R11,R12,R13,R14,R15
Note that tokens are treated in an *exclusive*, not inclusive, manner. The end
token from the initial request was '9' which corresponded to R10. When the 2nd
request was made, R10 did not appear again, even though from=9 was specified. If
you know the token, you already have the data.
Pagination Response
~~~~~~~~~~~~~~~~~~~
Responses to pagination requests MUST follow the format::
{
"chunk": [ ... , Responses , ... ],
"start" : $streamtoken,
"end" : $streamtoken
}
Where $streamtoken is an opaque token which can be used in another query to
get the next set of results. The "start" and "end" keys can only be omitted if
the complete dataset is provided in "chunk".
Events
------
@ -521,8 +427,8 @@ returns an ``end`` token which can be used with the event stream.
{{sync_http_api}}
Events in a room
~~~~~~~~~~~~~~~~
Types of room events
~~~~~~~~~~~~~~~~~~~~
Room events are split into two categories:
@ -544,7 +450,7 @@ convention, e.g. ``com.example.myapp.event``. This ensures event types are
suitably namespaced for each application and reduces the risk of clashes.
State events
~~~~~~~~~~~~
++++++++++++
State events can be sent by ``PUT`` ing to
|/rooms/<room_id>/state/<event_type>/<state_key>|_. These events will be
@ -587,7 +493,7 @@ In some cases, there may be no need for a ``state_key``, so it can be omitted::
See `Room Events`_ for the ``m.`` event specification.
Message events
~~~~~~~~~~~~~~
++++++++++++++
Message events can be sent by sending a request to
|/rooms/<room_id>/send/<event_type>|_. These requests *can* use transaction
@ -655,6 +561,105 @@ The redaction event should be added under the key ``redacted_because``. When a
client receives a redaction event it should change the redacted event
in the same way a server does.
Pagination
----------
.. NOTE::
The paths referred to in this section are not actual endpoints. They only
serve as examples to explain how pagination functions.
Pagination is the process of dividing a dataset into multiple discrete pages.
Matrix makes use of pagination to allow clients to view extremely large datasets.
These datasets are not limited to events in a room (for example clients may want
to paginate rooms in addition to events within those rooms). Regardless of *what*
is being paginated, there is a common underlying API which is used to
to give clients a consistent way of selecting subsets of a potentially changing
dataset. Requests pass in ``from``, ``to``, ``dir`` and ``limit`` parameters
which describe where to read from the stream. ``from`` and ``to`` are opaque
textual 'stream tokens' which describe the current position in the dataset.
The ``dir`` parameter is an enum representing the direction of events to return:
either ``f`` orwards or ``b`` ackwards. The response returns new ``start`` and
``end`` stream token values which can then be passed to subsequent requests to
continue pagination. Not all endpoints will make use of all the parameters
outlined here: see the specific endpoint in question for more information.
Pagination Request Query Parameters
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Query parameters:
from:
$streamtoken - The opaque token to start streaming from.
to:
$streamtoken - The opaque token to end streaming at. Typically,
clients will not know the item of data to end at, so this will usually be
omitted.
limit:
integer - An integer representing the maximum number of items to
return.
dir:
f|b - The direction to return events in. Typically this is ``b`` to paginate
backwards in time.
'START' and 'END' are placeholder values used in these examples to describe the
start and end of the dataset respectively.
Unless specified, the default pagination parameters are ``from=START``,
``to=END``, without a limit set.
For example, if an endpoint had events E1 -> E15. The client wants the last 5
events and doesn't know any previous events::
S E
|-E1-E2-E3-E4-E5-E6-E7-E8-E9-E10-E11-E12-E13-E14-E15-|
| | |
| _____| <--backwards-- |
|__________________ | | ________|
| | | |
GET /somepath?to=START&limit=5&dir=b&from=END
Returns:
E15,E14,E13,E12,E11
Another example: a public room list has rooms R1 -> R17. The client is showing 5
rooms at a time on screen, and is on page 2. They want to
now show page 3 (rooms R11 -> 15)::
S E
| 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 | stream token
|-R1-R2-R3-R4-R5-R6-R7-R8-R9-R10-R11-R12-R13-R14-R15-R16-R17| room
|____________| |________________|
| |
Currently |
viewing |
|
GET /roomslist?from=9&to=END&limit=5
Returns: R11,R12,R13,R14,R15
Note that tokens are treated in an *exclusive*, not inclusive, manner. The end
token from the initial request was '9' which corresponded to R10. When the 2nd
request was made, R10 did not appear again, even though from=9 was specified. If
you know the token, you already have the data.
Pagination Response
~~~~~~~~~~~~~~~~~~~
Responses to pagination requests MUST follow the format::
{
"chunk": [ ... , Responses , ... ],
"start" : $streamtoken,
"end" : $streamtoken
}
Where $streamtoken is an opaque token which can be used in another query to
get the next set of results. The "start" and "end" keys can only be omitted if
the complete dataset is provided in "chunk".
Pagination APIs
~~~~~~~~~~~~~~~
{{message_pagination_http_api}}
Rooms
-----

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