Tuesday, August 1, 2017

SPFx: An ISV Insight to Microsoft's latest customization model

As promised, here is my blog post about this session from @spsnyc

Thanks for all the great reviews, the comment I got the most was that it had too much great info.

My greatest challenge writing this session was focusing on a few advanced topics that were not widely covered by other SPFx sessions.

There is an influx of SPFx sessions on every conference these days, and I find the majority of them (maybe rightly so) focus on beginner level introduction to SPFx.

What I wanted to do with this session is something different.

Focus on a few important more advanced topics that were not widely covered by other speakers.

This led me to build this level 300-400 session that focuses on these key points:

  • Publishing versions
  • Pushing updates through CDN
  • Sharing code between projects
  • Building a custom PropertyPane property
I cover these points in a deeper level, and accompany them with complete source code example of my solution.

Here is the slide show:

* I highly recommend downloading and viewing the slideshow in PowerPoint to view my speaker notes and comments on each slide.

Here is the code samples:


Please feel free to give me more comments and suggestions on what would you like to hear about, so I could update my session accordingly.

Also consider following the github project since I will publish updates to the source examples to it.


Thursday, July 27, 2017

How to avoid breaking your SPFx project when dependencies change

Your SPFx project has a short list of dependencies.
They are listed in package.json

Thing is, these dependencies have a looong list of dependencies themselves, so that you end up with over 300MB folder of node_modules by the time you finish running npm install on a new SPFx project.

As most of you probably noticed, SPFx by default has a .gitignore file that excludes node_modules from ever going into your source control.

Which is a good thing - these packages are monitored and controlled by their authors and you don't need to manage all that code in your project, do you?

That means, whenever you move to a new computer or a new developer start working on a project, after cloning that project they must also run npm install before they can start working.

Now, npm install will start loading packages and dependencies as of TODAY, not as of when the project or the SPFx framework were compiled.

Some dependencies are specified by a version number, so no worries there (as long as the author did not re-publish new code with the same version number).

Others are specified as latest, or "*" or just with a major version - allowing minor versions updates. Since minor version updates suppose to be fully backward compatible and not contain breaking changes - sometimes that is not the case.

So, you go to your new PC, run npm install, and your project does not build.
You get a ton of errors, version mismatch, and have no clue why.

The reason would be probably a dependency you had was updated during that time (or god forbid - removed from npm!) which now breaks your project.

That is something I talked about during the first DevKitchen I attended, when I first saw SPFx. Having a huge list of dependencies I don't control, my project rely on, and that I don't have a copy of scared me.

And sure enough, since that day until today I had at least 4 episodes of dependency hell.

What can you do today

Without going into what Microsoft can and should do to avoid this in the future, here is what I plan to do and encourage you guys to do as well:

1. Build a test SPFx project, call it "Sanity"
2. Run npm install, and make sure the demo web part works by running gulp serve
3. Remove the .gitignore file
4. Store the entire huge project in your source control

Every so often, run npm update on this project.
Test if it is working - and if yes, commit the changes.

However, if your project fails to build, you know you got a breaking change. Do not commit, it will probably get fixed within a few hours.

Note that some breaking changes may come from a globally installed package, such as typescript.
So, it is a good practice to log these versions as well somewhere in your project. You can get that list by running "npm ls".

What to do if your project breaks

Now, once one of your project fails to build, look at where the errors are coming from.
It will probably tell you the packages and their dependencies.
Now, you can compare these packages with the ones you have in your "Sanity" project, and once you identify the ones causing the problem you can manually revert it by running:
npm uninstall {package}
npm install {package}@{last working version}

If you don't have that "Sanity" package, and do have a working version on a different computer - try to compare the versions between these two.

A quicker fix might be to simply copy the node_modules folder from the working project into your new broken projects.

It could be very frustrating spending valuable dev hours on maintenance instead of productive work, but hopefully these steps could help you cut down those hours.

SPFx project breaking after moving to a new computer

So, as I was finishing my demo for #SPSNYC about SPFx, I moved my demo from my PC to my Mac laptop.

Running npm install everywhere, it all goes smooth, except I didn't have TypeScript installed.

So, naturally - I installed TypeScript:
npm install -g typescript

Next, I went to verify all demos were working.

Most were, one project refused to build.

Trying to build it yielded an error:

xxx:sharedcode xxx$ tsc
node_modules/@microsoft/sp-http/lib/httpClient/HttpClientResponse.d.ts(15,22): error TS2420: Class 'HttpClientResponse' incorrectly implements interface 'Response'.
  Types of property 'type' are incompatible.
    Type 'string' is not assignable to type 'ResponseType'.
node_modules/@types/react/index.d.ts(165,11): error TS2559: Type 'Component
' has no properties in common with type 'ComponentLifecycle


That probably means, one or more packages have changed since the time I created this project to the time I built it.

Luckily, finding out where the error comes from was rather simple.

See, the error complained an SPFx package was incorrectly implementing an interface.
That means, it is either missing a member, or have the wrong type of a member.
It even gave me the member name: Type, which was set to string instead of ResponseType.

So, I opened the HttpClientResponse.d.ts that reported the error, and noticed its "Type" member was of type "String".

Right click on the "Responce" interface, go to definition - indeed showed that Type was defined as "ResponseType".

I knew that my SPFx dependencies version didn't change, so I quickly checked the TypeScript version using "tsc -v"

On my laptop, it was 2.4.2
On my PC it was 2.1.5

So, the fix was simple:
1. npm uninstall -g typescript
2. npm install -g typescript@2.1.5

And viola! Everything back to normal.

Working with SPFx, you should know this is not the first time something like that happened, and unless steps are taken - this won't be the last either.

I will talk about this dependencies "hell" and what can be done about it during my session at #SPSNYC, so come see me if you can!