Tuesday, 29 September 2020

Sunday, 13 September 2020

Building better Software Thoughts

Overview:  I see a lot of development teams, and they always seem to have areas they are good at and capabilities teams need improvement on.  Key is culture and building a happy team where team members trust and help one another.

Building a culture where teams enjoy code reviews is also key for successful Software projects.   To improve software, reviewing various areas not only code reviews are essential.  For me, clear requirements are the number 1 factor in improving teams performance.  

Companies are getting better at building software; I aim to work on these topics to improve the delivery of software within scrum teams:

  1. Code Reviews & Peer Reviews (Daily reviews are awesome, should be pretty short and enjoyable not someone trying to show off or hours long)
  2. Collaboration (Standups, Slack/Teams, Code tools have collaboration built in)
  3. Documentation & Requirements Reviews
  4. Better tooling including better CI/CD tooling including static analysis tools
  5. Unit Testing, automate coding standards, Integration testing, UI Testing, and API testing 
  6. Requirements (Use Stories are clear and Acceptance Criteria)
  7. Cadence is improving thanks predominately to Agile practices; I like short release cycles (2-3 weeks depending on the team and industry).  Changing requirements, indecision kills software projects.  Agile helps, but decisive knowledgeable product owners increase the likelihood of the project succeeding.

Benefits of Code, Documentation and Requirement Reviews:

  1. Improved software quality & product delivery
  2. Share domain knowledge
  3. Training team members (useful for onboarding new team members)
  4. Reduce support and fix costs
  5. Lower cost & faster development

Options Layering API's on Data Sources - Micrososervices kind of

Hasura takes data sources such as SQL, Postgress & MySQL and converts it into GraphQL API's.  SQL Server is in preview.  Service is available on Azure and hooks into AAD and AAD B2C.  Hasuru looks extremely interesting and useful.  Potentially a great time saver.

CDS/DataFelx/Oakdale - Allows for Entity creation and provides REST API's.

SharePoint lists provide HTTP API's for CRUD operations.

REST API's vs GraphQL

OpenAPI specification (previously known as the Swagger specification) is my default for an API, this allows for a known RESTful API that anyone with access can use.   Open API has set contracts that returned defined objects which is great, you can work with the API like a database with simple CRUD operations as defined by the specification.  The issue is that the returned objects are fixed in structure so you may need 2 or more queries to get the data you are looking for.  Alternatively, GrapghQL allows the developer to ask for the data exactly as the want it.
Open API example:
/api/user/{2} returns the user object  // Get the user object for user 2
/api/users/{2}/orders/10  // Returns the last 10 orders for the user
GraphQL example:
Post a single HTTP request.
query {
 User(id: "") {
    orders(last: 10 {

Database Option Notes:
PostgreSQL - Hybrid relation database (Communitity edition free, standard and enterprise higher loads) sits on Linex but can also use Windows OS.  Replicas are used for additional read-only nodes (I think up to 5 geo relicas allowed) 
Can be hosted on Azure or AWS IaaS.  PostgreSQL is also offered as a fully managed service (PaaS) on Azure (either single server or hyperscale).
MariaDB community fork off MySQL - Open source relation database used in the LAMP app stack.  Azure MySQL manage service can have up to 5 replicas for read heavy workloads.

Sunday, 6 September 2020

Working with CDS data structures for non CRM types

Overview:  I am working on a Power Platform solution and I need to use CDS.  Basically, I need to be able to see and edit values within CDS.

Option 1: Microsoft SQL Server Management Studio (SSMS) version 18.6 allows connectivity and read-only access.  Here are the instructions.

Option 2XrmToolBox has fantastic tools for Dynamics and Power Apps.  There are a lot of individual tools from various contributors.

Here I am using "Entity Relationship Diagram Creator" to look at the relationships between the CDS entities.

Saturday, 5 September 2020

Reducing Power Apps Dynamic calls and where to store Power Apps data.

Overview:  Power Apps is driven by data and generally that data comes from Connectors.  So the great news is there are a lot of different connectors and if in trouble I always find the custom connector can be relied upon.  When working with Power Apps, it is not as simple as just having a data source and consuming it, one needs to consider all the data sources, do we need live data, performance.  Basically, going and dynamically pulling lots of dynamic sets of data repeatedly leads to poor performance.

Identify data sources:  CDS, Azure SQL, SQL on-prem, CosmosDB, RSS, Open API's...

Understand the security, and the amount of data being pulled.  For example, if we need all the airport codes in the world for a drop down so the user can choose their closest airport e.g. JFK is for New York John F Kennedy airport.  There are roughly 4000 commercial airports in the world. 

Options: Call an Open API service.  Power App by default returns sets of 500, Power Apps max return count is 2000.  You still need to perform 2 calls with paging to get the full data set.  You could use a type ahead if the API supports it, but their will be a lag after each keystroke when Power Apps runs out to the service.  And there will be a lot of calls.  More suitable would be to do 2 calls with 2,000 record for each call and bind the control to the returned data.

A further improvement would be to store the airport lookup on data load or on first request, then subsequent requests would use the table/collection.  In effect, you are locally caching all the airport codes using 2 calls for each Power Apps user session.

For the airport example, one could also store the data using a Excel import, but beware the data is imported into Power Apps and store locally.  Big issue is the data is static in Power Apps, to update it, you need to re-import the Excel table.  So brilliant for sat days of the week or Months of the year as these never change.  Fairly static data like airport codes work well, but require a publisher level overwrite to update the list.  Also, storing extreme amounts of static data leads to bloat of the app and that data still needs to be loaded.  So I would not consider it for 100k+ items as a general rule.  

More Info:

Todd Baginski has a great video on using Excel import and creating language variations/multi-lingual Power Apps using Excel imports.

Alagunila Meganathan on C# Corner has a good post on Excel Imports for Power Apps.