From a87309e5ddda960149e53c4aaad6c3870bd22045 Mon Sep 17 00:00:00 2001
From: Benjamin Bertrand <benjamin.bertrand@esss.se>
Date: Mon, 8 Jan 2018 09:17:35 +0100
Subject: [PATCH] Add pagination to API
Pagination information (next, prev, first, last) is included in the Link
HTTP header.
The total number of entries is provided in the X-Total-Count HTTP
header.
---
app/api/inventory.py | 13 ++++++-----
app/api/network.py | 13 +++++------
app/api/user.py | 2 +-
app/api/utils.py | 51 ++++++++++++++++++++++++++++++++++++++------
app/utils.py | 7 +++---
5 files changed, 60 insertions(+), 26 deletions(-)
diff --git a/app/api/inventory.py b/app/api/inventory.py
index 2a75c36..91d0b1f 100644
--- a/app/api/inventory.py
+++ b/app/api/inventory.py
@@ -35,8 +35,7 @@ def get_item_by_id_or_ics_id(id_):
@bp.route('/items')
@jwt_required
def get_items():
- # TODO: add pagination
- return get_generic_model(models.Item, request.args,
+ return get_generic_model(models.Item,
order_by=models.Item.created_at)
@@ -133,13 +132,13 @@ def create_item_comment(id_):
@bp.route('/actions')
@jwt_required
def get_actions():
- return get_generic_model(models.Action, request.args)
+ return get_generic_model(models.Action)
@bp.route('/manufacturers')
@jwt_required
def get_manufacturers():
- return get_generic_model(models.Manufacturer, request.args)
+ return get_generic_model(models.Manufacturer)
@bp.route('/manufacturers', methods=['POST'])
@@ -152,7 +151,7 @@ def create_manufacturer():
@bp.route('/models')
@jwt_required
def get_models():
- return get_generic_model(models.Model, request.args)
+ return get_generic_model(models.Model)
@bp.route('/models', methods=['POST'])
@@ -165,7 +164,7 @@ def create_model():
@bp.route('/locations')
@jwt_required
def get_locations():
- return get_generic_model(models.Location, request.args)
+ return get_generic_model(models.Location)
@bp.route('/locations', methods=['POST'])
@@ -178,7 +177,7 @@ def create_locations():
@bp.route('/status')
@jwt_required
def get_status():
- return get_generic_model(models.Status, request.args)
+ return get_generic_model(models.Status)
@bp.route('/status', methods=['POST'])
diff --git a/app/api/network.py b/app/api/network.py
index ef2c28c..b48e05d 100644
--- a/app/api/network.py
+++ b/app/api/network.py
@@ -9,7 +9,7 @@ This module implements the network API.
:license: BSD 2-Clause, see LICENSE for more details.
"""
-from flask import Blueprint, request
+from flask import Blueprint
from flask_jwt_extended import jwt_required
from .. import models
from ..decorators import jwt_groups_accepted
@@ -21,8 +21,7 @@ bp = Blueprint('network_api', __name__)
@bp.route('/scopes')
@jwt_required
def get_scopes():
- # TODO: add pagination
- return get_generic_model(models.NetworkScope, request.args,
+ return get_generic_model(models.NetworkScope,
order_by=models.NetworkScope.name)
@@ -38,8 +37,7 @@ def create_scope():
@bp.route('/networks')
@jwt_required
def get_networks():
- # TODO: add pagination
- return get_generic_model(models.Network, request.args,
+ return get_generic_model(models.Network,
order_by=models.Network.address)
@@ -55,8 +53,7 @@ def create_network():
@bp.route('/interfaces')
@jwt_required
def get_interfaces():
- # TODO: add pagination
- return get_generic_model(models.Interface, request.args,
+ return get_generic_model(models.Interface,
order_by=models.Interface.ip)
@@ -71,7 +68,7 @@ def create_interface():
@bp.route('/macs')
@jwt_required
def get_macs():
- return get_generic_model(models.Mac, request.args,
+ return get_generic_model(models.Mac,
order_by=models.Mac.address)
diff --git a/app/api/user.py b/app/api/user.py
index 8868d30..ba22298 100644
--- a/app/api/user.py
+++ b/app/api/user.py
@@ -23,7 +23,7 @@ bp = Blueprint('user_api', __name__)
@bp.route('/users')
@jwt_required
def get_users():
- return get_generic_model(models.User, request.args,
+ return get_generic_model(models.User,
order_by=models.User.username)
diff --git a/app/api/utils.py b/app/api/utils.py
index 64471fd..168b266 100644
--- a/app/api/utils.py
+++ b/app/api/utils.py
@@ -9,6 +9,7 @@ This module implements useful functions for the API.
:license: BSD 2-Clause, see LICENSE for more details.
"""
+import urllib.parse
import sqlalchemy as sa
from flask import current_app, jsonify, request
from ..extensions import db
@@ -23,20 +24,58 @@ def commit():
raise utils.CSEntryError(str(e), status_code=422)
-def get_generic_model(model, args, order_by=None):
+def build_pagination_header(pagination, base_url, **kwargs):
+ """Return the X-Total-Count and Link header information
+
+ :param pagination: flask_sqlalchemy Pagination class instance
+ :param base_url: request base_url
+ :param kwargs: extra query string parameters (without page and per_page)
+ :returns: dict with X-Total-Count and Link keys
+ """
+ header = {'X-Total-Count': pagination.total}
+ links = []
+ if pagination.page > 1:
+ params = urllib.parse.urlencode({'per_page': pagination.per_page,
+ 'page': 1,
+ **kwargs})
+ links.append(f'<{base_url}?{params}>; rel="first"')
+ if pagination.has_prev:
+ params = urllib.parse.urlencode({'per_page': pagination.per_page,
+ 'page': pagination.prev_num,
+ **kwargs})
+ links.append(f'<{base_url}?{params}>; rel="prev"')
+ if pagination.has_next:
+ params = urllib.parse.urlencode({'per_page': pagination.per_page,
+ 'page': pagination.next_num,
+ **kwargs})
+ links.append(f'<{base_url}?{params}>; rel="next"')
+ if pagination.pages > pagination.page:
+ params = urllib.parse.urlencode({'per_page': pagination.per_page,
+ 'page': pagination.pages,
+ **kwargs})
+ links.append(f'<{base_url}?{params}>; rel="last"')
+ if links:
+ header['Link'] = ', '.join(links)
+ return header
+
+
+def get_generic_model(model, order_by=None):
"""Return data from model as json
:param model: model class
- :param MultiDict args: args from the request
:param order_by: column to order the result by
:returns: data from model as json
"""
- query = utils.get_query(model.query, request.args)
+ kwargs = request.args.to_dict()
+ page = int(kwargs.pop('page', 1))
+ per_page = int(kwargs.pop('per_page', 20))
+ query = utils.get_query(model.query, **kwargs)
if order_by is None:
order_by = getattr(model, 'name')
- instances = query.order_by(order_by)
- data = [instance.to_dict() for instance in instances]
- return jsonify(data)
+ pagination = query.order_by(order_by).paginate(page, per_page)
+ data = [item.to_dict() for item in pagination.items]
+ header = build_pagination_header(pagination, request.base_url, **kwargs)
+ return jsonify(data), 200, header
def create_generic_model(model, mandatory_fields=('name',), **kwargs):
diff --git a/app/utils.py b/app/utils.py
index dd9fbec..ee68efe 100644
--- a/app/utils.py
+++ b/app/utils.py
@@ -135,15 +135,14 @@ def get_model_choices(model, allow_none=False, attr='name', query=None):
return choices
-def get_query(query, args):
+def get_query(query, **kwargs):
"""Retrieve the query from the arguments
:param query: sqlalchemy base query
- :param MultiDict args: args from a request
+ :param kwargs: kwargs from a request
:returns: query filtered by the arguments
"""
- if args:
- kwargs = args.to_dict()
+ if kwargs:
try:
query = query.filter_by(**kwargs)
except (sa.exc.InvalidRequestError, AttributeError) as e:
--
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