198 Lotus blogs updated hourly. Who will post next? Home | Blogs | Search | About 
 
Latest 7 Posts
Universal Data Replication
Wed, Oct 18th 2017 182
The power of Domain Specific Languages
Thu, Jun 15th 2017 4
Darwino as the IBM Domino reporting graal
Sat, Mar 11th 2017 6
Schemaless GraphQL
Fri, Mar 3rd 2017 7
Get your apps integrated with IBM Connections, cloud and on-premises!
Fri, Feb 17th 2017 6
When SQL meets NoSQL, you get the best of both worlds!
Thu, Jan 26th 2017 7
ReactJS or AngularJS? What about something else?
Wed, Jan 25th 2017 5
Top 10
Universal Data Replication
Wed, Oct 18th 2017 182
Why AngularJS sounds familiar to XPages developers...
Tue, Jan 3rd 2017 11
Darwino, and Java applications, on Microsoft Azure!
Wed, Jul 20th 2016 9
When your Domino app meet the cloud, IBM Connections or Microsoft Azure!
Thu, Sep 22nd 2016 9
IBM Bluemix - Eclipse Developer Exprience
Mon, May 16th 2016 7
When SQL meets NoSQL, you get the best of both worlds!
Thu, Jan 26th 2017 7
Schemaless GraphQL
Fri, Mar 3rd 2017 7
The very first Darwino workshop in Germany was a success!
Tue, Dec 6th 2016 6
The king is dead, long live to the new iOS Java king!
Thu, Dec 22nd 2016 6
Get your apps integrated with IBM Connections, cloud and on-premises!
Fri, Feb 17th 2017 6


Schemaless GraphQL
Twitter Google+ Facebook LinkedIn Addthis Email Gmail Flipboard Reddit Tumblr WhatsApp StumbleUpon Yammer Evernote Delicious
   

FaceBook officially introduced a few months ago a new technology called GraphQL. Well, rather than really being new, FaceBook made public and open source their internal graph query engine. It starts to be widely used for exposing APIs. For example, IBM Watson Worskpace makes use of it. I also heard that IBM Connections will also use it.

In a nutshell, it allows powerful, tailored queries including navigation between the data sources, in a single query. As a result, it minimizes the number of requests sent by the client to the server, which is a performance boost. Moreover, it proposes a single query format regardless of the data source. Basically, it means that you can query data from an RDBMS or an LDAP directory almost identically, while getting a consistent response format. All good!

To make the queries discoverable, it uses a schema to define the query parameters, the JSON result as well as the graph traversal links.  If this is appealing, it forces the server to implement these schemas before the queries can be emitted by the client. The whole data and navigation models have to be known and implemented up front. Hum, not only this slows down application prototyping, but it makes it hard to link micro-services that don't know about each other.  It also does not work with truly dynamic services, like a JSON document store, where the document schema can be unknown.  Crap, this is exactly what Darwino offers. So the question is: can we still use GraphQL for dynamic services, where data  schema can be static, dynamic or a mix of both? I saw a few posts on the subject but no solution so far.

Fortunately, GraphQL has the notion of an optional field alias. An alias renames a field, so it can appear multiple times in the same root. As a field can also have parameters, we can "tweak" the engine to implement dynamic field accessors. How? Simply by inverting the roles: the alias becomes the field name while the field is a dynamic, typed, JSON path evaluation on the source document.

Ok, let me give you an example. Suppose that we have the following document as a source:
{
  name: "MyProject",
  budget: {
    amount: 10000,
    currency: "USD"
  }
}
The dynamic query to extract the project name and the budget will be like:
{
  doc: Document(unid:"projectid", database:"project") {
    _unid,
    name: string(path:"$.name"),
    budget: number(path:"$.budget.amount")
  }
}
'string' and 'number' (as well as others, like boolean...) are typed, pseudo field names that are actually evaluating JSON path queries on the source document. And because the path is passed as an argument, it can be fully dynamic! We are using JSON path here, but any interpreted language could be used, including JavaScript or others. Also note that the Document accessor is also implemented as a field with parameters. This triggers the actual load of the JSON document from the database.
How does that sound? You can find a real example dealing with the JSON store in the Darwino playground:

But this is not enough, as we also need to implement the links to navigate the graph. For example, we need to navigate to a JSON document by id, that id being a field in the current object. To make this possible, we introduce here the notion of computed parameter, using the ${....} syntax (remember JSF?).
The pseudo query bellow assumes that you have tasks documents that can be accessed using the parent project id:
{
  doc: Document(unid:"projectid", database:"project") {
    _unid,
    name: string(path:"$.name"),
    budget: number(path:"$.budget.amount")
    tasks: Documents(parent:"${_unid}", database:"tasks") {
     taskname: string(path:"$.name"),
    }
  }
}
The drawback of this solution is that every property becomes a string, to accept a formula. Another solution would duplicate all the fields and have, for example, parent$ as a computed version of parent. As the whole library is under development, I'm not sure yet what's best, so any feedback is welcome!
Note that Documents returns a collection of documents, as opposed to Document that only returns one.

Of course, this is a simple introduction to a schemaless implementation of GraphQL. There are more details, but it expands the GraphQL technology by making it more dynamic, while the retaining the static parts. Look, for example, at this snippets mixing static and dynamic attributes:
The early Darwino 2.0 code includes this capability in its Java based implementation, released as open source on darwino.org. Any GraphQL object can implement a specific interface that will give it the dynamic capability (json path...) on top of its static fields. If you go back to the previous example, you'll see that the document UNID is a static field specific to the Darwino JSON document.

There are more to discover, but hold on: if our session is accepted at Engage 2017, Paul Withers and I will give more details on the implementation, along with an IBM Notes/Domino implementation!


---------------------
http://blog.riand.com/2017/03/schemaless-graphql.html
Mar 03, 2017
8 hits



Recent Blog Posts
182
Universal Data Replication
Wed, Oct 18th 2017 7:21p   Philippe Riand
One of the Darwino piece of code that I'm the most proud of is the replication engine. If a majority of our customers see it as a Domino to JSON replication engine, it goes far beyond that. In reality, it can replicate between virtually any data sources. It is a true, two ways, multi-point replication engine, borrowing some ideas from IBM Domino but going beyond its venerable ancestor in multiple places. The architectureThe main idea is that any data set can be represented as a set decorated J
4
The power of Domain Specific Languages
Thu, Jun 15th 2017 11:03p   Philippe Riand
We are all used to configuration files, whenever they are XML, JSON or simply text based. If this is ok for simple configurations, but it falls short when the complexity increases. The biggest issue is that they cannot provide more than what they are designed for, basically static values. Let's suppose, for example, that we have an XML configuration file exposing a property like: trueOk, simple enough. This property can be true or false. But now what if I want a more dynamic value, like true
6
Darwino as the IBM Domino reporting graal
Sat, Mar 11th 2017 8:31p   Philippe Riand
Reports, dashboards, data analytics... have been the conundrum of IBM Notes/Domino since the beginning. Its proprietary data structure, the absence of standard APIs and its deficient query capability make it very difficult. This has been ranked as one of the top need for any for business applications. I know several business partners who created great Domino solutions but struggling with poor reporting capabilities. Of course some attempts were made to fix it: LEI, DB2NSF,.. all incomplete and
8
Schemaless GraphQL
Fri, Mar 3rd 2017 11:56p   Philippe Riand
FaceBook officially introduced a few months ago a new technology called GraphQL. Well, rather than really being new, FaceBook made public and open source their internal graph query engine. It starts to be widely used for exposing APIs. For example, IBM Watson Worskpace makes use of it. I also heard that IBM Connections will also use it. In a nutshell, it allows powerful, tailored queries including navigation between the data sources, in a single query. As a result, it minimizes the number of re
6
Get your apps integrated with IBM Connections, cloud and on-premises!
Fri, Feb 17th 2017 4:51a   Philippe Riand
I've been using this blog to share some of the techniques we use in ProjExec to get tightly integrated with the Connections platform. I got a lot of feedback from developers who wanted to know more, so I'm moving a step further: Jesse Gallagher and I will describe these techniques in a breakout session @Connect 2017! DEV-1430 : IBM Connections Integration: Exploring the Long List of Options Program : Development, Design and Tools Topic : Enterprise collaboration Session Type : Breakout Sessio
7
When SQL meets NoSQL, you get the best of both worlds!
Thu, Jan 26th 2017 11:46p   Philippe Riand
At the heart of Darwino is an advanced, portable JSON document store, implemented on top of any relational database. I'm often being asked the following question "why did you implement that on top of an RDBMS?". Behind the scene, the real question is: "why are you not using MongoDB or another nosql database?" Well, I'm generally answering it with multiple arguments:It leverages all the RDBMS well known capabilities: transactions, data integrity, security, backups, performance, reporting, a
5
ReactJS or AngularJS? What about something else?
Wed, Jan 25th 2017 9:25p   Philippe Riand
So far, ProjExec has been a really good citizen in the IBM/ICS world as we tried to reuse the core Connections stack as much as can (Dojo, OneUI, ...). But these technologies start to age while the browser technologies evolved a lot in the past years: what required a whole bunch of JavaScript using Dojo/JQuery can now be squeezed in a few lines using new libraries! It is time to change gears. We started to look at what technology would better fit our needs. The main requirements are: Make the d
11
Why AngularJS sounds familiar to XPages developers...
Tue, Jan 3rd 2017 5:53p   Philippe Riand
When I started to look at AngularJS a few years ago, I surprisingly found myself quickly comfortable with this technology. One of the reason is that many of its concepts are shared with XPages. Of course, there are fundamental differences, the most obvious being AngularJS a pure client technology while XPages, based on JSF, is a server side one. But still, they share a lot! If you know XPages, your experience understanding AngularJS should be similar to mine. I'm basing my experience on Angul
6
The king is dead, long live to the new iOS Java king!
Thu, Dec 22nd 2016 11:08p   Philippe Riand
When presenting Darwino, I'm often asked the question how do we run Java natively on iOS, or other platforms that are not known to be Java friendly? Well, we started this journey a few years ago, but the landscape of cross platform Java evolved a lot since that. Let me go through the history and explain where we stand now, as a new king has just been proclaimed. If you thing the story is too long, then just go to Multi OS Engine for the answer. Back to the dark age, the most promising solution
6
The very first Darwino workshop in Germany was a success!
Tue, Dec 6th 2016 5:12p   Philippe Riand
It happened in Cologne, Germany, where 8 different companies joined us to better understand Darwino and get their hands dirty with the code. It reminded me the first XPages workshop we did in Westford in 2008, before we launched the technology at Lotusphere. Same spirit, with highly motivated people, ready to enhance their existing Domino applications!We had several IBM champions, OpenNTF board members, and even the CTO of the great Multi-OS-Engine. If the crowd learnt about the technology, we




Created and Maintained by Yancy Lent - About - Planet Lotus Blog - Advertising - Mobile Edition