feat(pagination): Implement paging

Author: petitchevalroux

lib/index.js

@@ -11,6 +11,7 @@ var update = require('./update')
 var del = require('./delete')
 var errors = require('./errors')
 var relationships = require('./relationships')
+var querystring = require('./querystring');
 var debug = require('debug')('loopback-component-jsonapi')
 
 module.exports = function (app, options) {
@@ -38,4 +39,5 @@ module.exports = function (app, options) {
   update(app, options)
   errors(app, options)
   del(app, options)
+  querystring(app, options)
 }

lib/querystring.js

@@ -0,0 +1,23 @@
+var utils = require('./utils');
+
+module.exports = function (app, options) {
+    var remotes = app.remotes();
+    remotes.before('**', function (ctx, next) {
+        if (utils.shouldNotApplyJsonApi(ctx, options)) {
+            return next();
+        }
+        var query = ctx.req.query;
+        ctx.args.filter = ctx.args.filter || {};
+        if(typeof(query.page) === 'object') {
+            [
+                {'from':'offset','to':'skip'},
+                {'from':'limit','to':'limit'}
+            ].forEach(function(p){
+                if(typeof(query.page[p.from]) === 'string') {
+                    ctx.args.filter[p.to] = query.page[p.from];
+                }
+            });
+        }
+        return next();
+    });
+};

test/find.test.js

@@ -251,6 +251,57 @@ describe('loopback json api component find methods', function () {
         })
     })
   })
+    describe('Paging should filter', function () {
+    beforeEach(function (done) {
+      Post.create({
+        title: 'deer can jump',
+        content: 'deer can jump really high in their natural habitat'
+      }, function () {
+        Post.create({
+          title: 'pigs dont fly',
+          content: "contrary to the myth, pigs don't fly!"
+        }, function () {
+          Post.create({
+            title: 'unicorns come from rainbows',
+            content: 'at the end of a rainbow may be a pot of gold, but also a mythical unicorn'
+          }, done)
+        })
+      })
+    })
+
+    it('should filter only one', function (done) {
+      request(app)
+        .get('/posts?page[limit]=1')
+        .expect(200)
+        .end(function (err, res) {
+          expect(err).to.equal(null)
+          expect(res.body.data.length).to.equal(1)
+          done()
+        })
+    })
+
+    it('should filter two', function (done) {
+      request(app)
+        .get('/posts?page[limit]=2')
+        .expect(200)
+        .end(function (err, res) {
+          expect(err).to.equal(null)
+          expect(res.body.data.length).to.equal(2)
+          done()
+        })
+    })
+
+    it('should skip first', function (done) {
+      request(app)
+        .get('/posts?page[limit]=1&page[offset]=1')
+        .expect(200)
+        .end(function (err, res) {
+          expect(res.body.data.length).to.equal(1)
+          expect(res.body.data[0].id).to.equal('2')
+          done()
+        })
+    })
+  })
 })
 
 describe('non standard primary key naming', function () {