feat(crud,crud-request,crud-typeorm): Added custom operators

[rgolea]

This is a first attempt to add custom operators to allow users to extend functionality. I still need some help with some tests but I believe this should close #149.

It should allow you to do something like the following:

@Crud({
  ...
  customOperators: {
    <operator key>: (field: string, param: string) => <returns a string>
  }
})

so, for an example like the following:

@Crud({
  ...
  customOperators: {
    intersects: (field: string, param: string) => `ST_Intersects(${field}, ST_GeomFromGeoJSON(:${param}))`
  }
})

You should be able to do something like: ?filter=geom||intersects||<some geojson> in order to filter the entries that actually intersect that geojson.

PS: Added tests as well

[rgolea]

@zMotivat0r would you please tell me if this is at least the right path to go on? I would like to proceed with my project but I won’t want to proceed on a path that will be on direct conflict with the official path that you guys might take.

[michaelyali]

First of all, @rgolea, thank you very much for your PR. I think the idea itself is awesome, but I haven't a chance to discover and review this PR closely.
I'm working now on some magor bugs and hopefully will review your PR soon.

[rgolea]

Thank you very much! Great project btw! If you need some help with the project, let me know: I will try to help however I can.

[rgolea]

Hi there @zMotivat0r! Is there any news on this?

[Mr-Plutus]

Hello! This is a very good and necessary contribution, it is often required to write custom operators in postgres

[Diluka]

@rgolea You need rebase and resolve the conflicts

[rgolea]

@Diluka I had it updated for about a month. I don't know if you guys abandoned the project. I will update it soon but I would love to know if it can be merged soon.

[heuristicAL]

Chiming in to hopefully push this review forward! 😃 This looks like a great feature!

[reececasey]

@rgolea just checking if you are still working on this, and looking at the conflicts?

[rgolea]

@reececasey I am very sorry but I have been swamped with work. I will do my best to update this over the weekend.

[Darkein]

@zMotivat0r have you been able to take a look ?

[michaelyali]

@Darkein yep, I was looking at this PR but unfortunately for it, at that moment I was working on a big update when I refactored a lot of parts and moved a lot of work to the interceptors and introduced search param mechanism as far as I remember.
And now there is a lot of conflicts :(

[rgolea]

@zMotivat0r @Darkein and unfortunately I’m currently mixed up in a lot of work and cannot get to it at the moment. If anyone wants to try to do the same thing it would be much appreciated. I cannot define at the moment the time I need to finish updating this PR. I wouldn’t close it because it can still be used as an example on how to implement it and I will update it eventually if no one gets to it before I do.

[Darkein]

I will take a look this week :)

[rgolea]

@Darkein feel free to copy all the code you need and ask me if you need anything! This is a great feature to have.

[Darkein]

@zMotivat0r @rgolea I've created a new PR recently, can you check it ?
#568

[rgolea]

@Darkein you my friend are a freaking hero. Give this man a medal. I will check it out today.

[rewiko]

I am trying to help and have forked this repo (can't reach the owner of this repo and do not have the credential for the npm repo).

See #710 (comment)

We can hopefully merge it via rewiko#5

[Darkein]

@rewiko You don't have to merge this one, #568 is a rebase of it