Implementation of ReplaceOrCreate - mysql

[Amir-61]

Hi @bajtos,

Please note this is just in progress implementation (Very initial implementation); just to make sure I'm on the right track.

Added functionality:

+Implemented replaceOrCreate method for loopback-connector-mysql

Side note:

• NPM test was failing out of the box.
• This patch requires changes from other modules including loopback-datasource-juggler, loopback-connector as well.

Connect to a spike task: https://github.com/strongloop-internal/scrum-loopback/issues/621

Thanks

[bajtos]

I don't see any obvious problems, besides the usual duplication of code.

@raymondfeng @superkhau PTAL too

[Amir-61]

@bajtos You proposed to use something like this.modifyOrCreate(model, data, options, this.buildReplaceFields, callback) here; however the buildReplaceFields method has this keyword in it; and it breaks var props = this.getModelDefinition(model).properties inside buildReplaceFields method when we pass buildReplaceFields method as the function argument; how about passing the function name like the way I did here and handeling it in modifyOrCreate?

[bajtos]

So there are two ways:

1. use the function name as you suggested, I think it's less clean because you cannot pass an anonymous function

2. pass a wrapper function that preserves this. You could use this.buildReplaceFields.bind(this), except that bind has terrible performance. Therefore this would be a more performant solution:

var self = this;
this.modifyOrCreate(model, data, options, function(model, data) { return self.buildReplaceFields(model, data); }, callback);

[Amir-61]

Hey @raymondfeng,

Please also review this patch as well!

I really appreciate your time and feedback :-)

[Amir-61]

Just clarifying: buildReplaceFields is a protected method implemented in loopback-connector; please see this PR

[Amir-61]

@superkhau / @raymondfeng,

This is a small patch which is ready for review.

I, also, just re-based and squashed the commits into one.

Thanks for your time!

[superkhau]

stick to 80 char limit, this one super long line is hard to read.

[superkhau]

should.equal same for all the ones in the file

[superkhau]

LGTM

[superkhau]

there is an extra space in front of MySQL here

[Amir-61]

@bajtos I prefer to wait for you to land this patch and this PR since they are related and need to be landed at the same time smoothly to pass CI tests.

Also this PR needs to be landed before landing this patch.