Spiced•13mo ago

Custom FilterIf Function

creating a custom filter if funciton

48 Replies

SpicedOP•13mo ago

@lee here we go

lee•13mo ago

How does this look

let query = db.query("messages");
if (args.author) {
  query = query.filter(q=>q.eq(q.field("author"), args.author);
}
const results = await query.collect();

let query = db.query("messages");
if (args.author) {
  query = query.filter(q=>q.eq(q.field("author"), args.author);
}
const results = await query.collect();

SpicedOP•13mo ago

Okay so yes, however i want to use if kind of like the filter function

export const getDiagrams = query({
  args: {
    searchQ: v.optional(v.string()),
    languageId: v.optional(v.string()),
  },
  handler: async (ctx, args) => {
    const identity = await ctx.auth.getUserIdentity();

    if (!identity) {
      throw new Error("Unauthorized");
    }
    const userId = identity.subject;

    let dashboard;
    if (args.searchQ != null || args.searchQ != undefined) {
      dashboard = await ctx.db
        .query("diagrams")
        .withSearchIndex("search_diagram_name", (q) =>
          q
            .search("title", args.searchQ ? args.searchQ : "")
            .eq("userId", userId),
        )
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();
    } else {
      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();
    }

    return dashboard;
  },
});

export const getDiagrams = query({
  args: {
    searchQ: v.optional(v.string()),
    languageId: v.optional(v.string()),
  },
  handler: async (ctx, args) => {
    const identity = await ctx.auth.getUserIdentity();

    if (!identity) {
      throw new Error("Unauthorized");
    }
    const userId = identity.subject;

    let dashboard;
    if (args.searchQ != null || args.searchQ != undefined) {
      dashboard = await ctx.db
        .query("diagrams")
        .withSearchIndex("search_diagram_name", (q) =>
          q
            .search("title", args.searchQ ? args.searchQ : "")
            .eq("userId", userId),
        )
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();
    } else {
      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();
    }

    return dashboard;
  },
});

This is an example that me and you worked on not long ago So a more optimal way would be

lee•13mo ago

And you don't want to put an if condition in the filter?

SpicedOP•13mo ago

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filterIf((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filterIf((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();

SO if the args.languageId is null, it gets ignored otherwise we filter

lee•13mo ago

There's no built-in way to do that. There needs to be an if condition somewhere. How about making a function like

function eqOrNull(f, val) {
  return (q) => (val === null || q.eq(q.field(f), val));
}

function eqOrNull(f, val) {
  return (q) => (val === null || q.eq(q.field(f), val));
}

and use it like filter(eqOrNull("databaseTypeId", args.languageId)) (I managed to not use an if condition 😁 )

SpicedOP•13mo ago

Haha, okay i got to give oyu that one issue, im using typescript

lee•13mo ago

You could do it inline? .filter(q=> args.languageId === null || q.eq(q.field("databaseTypeId"), args.languageId)) Which duplicates the value but it should typecheck

SpicedOP•13mo ago

Huh, that actually worked?

lee•13mo ago

You could add types to the eqOrNull helper. It does have well-defined types. But i'm no typescript expert

SpicedOP•13mo ago

Although i really wanted something not inline like a filterIf

lee•13mo ago

Well you could make a customQuery that does that. Sounds tricky but it should work

SpicedOP•13mo ago

I might need your help to start Any resources on custom query?

ballingt•13mo ago

Isn't TypeScript ok with @lee's original code?

let query = db.query("messages");
if (args.author) {
  query = query.filter(q=>q.eq(q.field("author"), args.author);
}
const results = await query.collect();

let query = db.query("messages");
if (args.author) {
  query = query.filter(q=>q.eq(q.field("author"), args.author);
}
const results = await query.collect();

SpicedOP•13mo ago

Yeah but we agreed not to use any ifs

ballingt•13mo ago

is this an interview challenge? 😛 ok I'm catching up on the thread now I see there are some viable things here, but you'd like to be able to compose these similarly to existing filters

SpicedOP•13mo ago

Haha, not really, just want to make a good function, rather create one now than have 50 if statements building my query ya know Ideally i would like to extend the current filter function with a custom filter that does the conditionals

ballingt•13mo ago

There's a bit in Anjana's section of this video https://youtu.be/UAjcJPMexfk?t=412 that might be interesting to you

Learn With Jason

YouTube

4 Web Devs, 1 App Idea (@WebDevCody, Anjana Vakil, Tom Ballinger)

Build a way to show real-time updates on the website for a Dungeons and Dragons-themed small business! 4 web devs built their own app based on this prompt. See what they built and watch their reactions to each other's work in this installment of the series. ---------------------------------------------------------------------- Huge thanks to Co...

ballingt•13mo ago

gist being that the partial query is an object that you can manipulate, so you can write functions that add things to it e.g.

let query = db.query("messages");
query = addAuthorFilter(query, author);
const results = await query.collect();

let query = db.query("messages");
query = addAuthorFilter(query, author);
const results = await query.collect();

SpicedOP•13mo ago

Ah, so filter as i go, collect last

ballingt•13mo ago

yeah you can compositionally build up your query, using whatever abstractions you desire, then run it at the end

SpicedOP•13mo ago

Interesting, i was trying to stray away from that as-well as a challenge because i found that too easy, suspiciously too easy

ballingt•13mo ago

your initial question made me think "why not use an if, that seems simplest" but if I follow you're writing a lot of queries (or anticipating writing a lot) and want to be able to change things in one spot — in which case helper functions like this that modify the query might be useful

SpicedOP•13mo ago

Exactly That was the whole point A single location to modify instead of searching everywhere’s

ballingt•13mo ago

I have to say I like @lee's .filter(q=> args.languageId === null || q.eq(q.field("databaseTypeId"), args.languageId)) but yeah if you're hoping to build your own abstractions, I'd do it as functions that modify the query in various ways. It's also possible to write custom filters by modifying the methods on db (that's what customFunction does) it's pretty involved, I'd recommend playing around composing functions at first then if you figure out a querying paradigm you like better writing a custom function that adds it to ctx.db

SpicedOP•13mo ago

Any resources on that? I wanna start playing around with some custom function Again ideally it would be like this Check the filterIf function BUT i dont know where to start

ballingt•13mo ago

see https://github.com/get-convex/convex-helpers/tree/main/packages/convex-helpers#custom-functions

GitHub

convex-helpers/packages/convex-helpers at main · get-convex/convex-...

A collection of useful code to complement the official packages. - get-convex/convex-helpers

ballingt•13mo ago

and https://stack.convex.dev/custom-functions

Customizing serverless functions without middleware

Re-use code and centralize request handler definitions with discoverability and type safety and without the indirection of middleware or nesting of wr...

SpicedOP•13mo ago

Would the way im thinking be possible in the first place?

ballingt•13mo ago

Yes, things like

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filterIf((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filterIf((q) => q.eq(q.field("databaseTypeId"), args.languageId))
        .collect();

are possible: you do it by extending or replacing the Convex implementation of db (DatabaseReader in a query) to do more things. Here your new filterIf method could replace the passed in query with the one Lee wrote. https://github.com/get-convex/convex-js/blob/main/src/server/database.ts#L103

GitHub

convex-js/src/server/database.ts at main · get-convex/convex-js

TypeScript/JavaScript client library for Convex. Contribute to get-convex/convex-js development by creating an account on GitHub.

SpicedOP•13mo ago

Huh i see Can you provide me with some more info so i can have a rough plan to implement tomorrow

ballingt•13mo ago

Those two linked posts are the place to start

SpicedOP•13mo ago

Custom functions? Although i do think it would be a good thing to have out of the box

ballingt•13mo ago

Yep, custom functions are how to you implement new DB behavior. If I were starting down this path I'd start with a function that Lee recommended

function eqOrNull(f, val) {
  return (q) => (val === null || q.eq(q.field(f), val));
}

function eqOrNull(f, val) {
  return (q) => (val === null || q.eq(q.field(f), val));
}

it's almost the same syntax:

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter(eqOrNull("databaseTypeId", args.langaugeId))
        .collect();

      dashboard = await ctx.db
        .query("diagrams")
        .withIndex("by_user", (q) => q.eq("userId", userId))
        .filter((q) => q.eq(q.field("isArchived"), false))
        //Inseting If Here
        .filter(eqOrNull("databaseTypeId", args.langaugeId))
        .collect();

SpicedOP•13mo ago

But we dont have the filterIf yet

ballingt•13mo ago

Although i do think it would be a good thing to have out of the box

This is helpful to hear, it's added to the list of requests!

SpicedOP•13mo ago

Oh wow, i didnt think it would get there, just a thought Might help people scaling from writing a lot of functions and such

ballingt•13mo ago

I don't totally see it, but if enough people ask for something it's hard to ignore. You're the first for this, if we hear enough that that's something people want because it's how they think about queries and they don't like the .filter(eqOrNull("databaseTypeId", args.langaugeId)) syntax we can do this Is there another query language you're used to that has this? always helpful to link to another system as an example of people finding it useful

SpicedOP•13mo ago

I mean i do a lot of daily coding with c# .net and MSSQL Basically in the filter if anything is null it kind of gets ignored unless SPECIFICALLY specified to be null

ballingt•13mo ago

ah totally, yeah special SQL NULL is special (edit: although I don't quite follow this example) In JavaScript it's usually undefined that works like this

SpicedOP•13mo ago

Well, my args.languageJd was undefined, but still it broke the wuery It threw me off cuz im trying to use my SQL knowledge here 😂

lee•13mo ago

in SQL if you have a WHERE field = $1 clause and $1 is null, isn't that always false? Whereas in this case you would want it to be true

SpicedOP•13mo ago

If its null, it gets everything (In c# Linq) I dont know the inner deeper working of LinQ but yeah

lee•13mo ago

Interesting, i've never worked with LinQ. I don't think the query builders i've worked with would do this Good to know the example, thanks! Can you give the LinQ syntax you're referring to?

ballingt•13mo ago

@Spiced +1, would love to see what the LinQ syntax for this kind of filter is.

SpicedOP•13mo ago

This is an example. Sorry i fell asleep

var list = context.Obj.Where(o => A.HasValue ? o.a == A : true);

var list = context.Obj.Where(o => A.HasValue ? o.a == A : true);

lee•13mo ago

That doesn't look like the language prividing a filterIf. It looks very similar to .filter(q=> A !== null ? q.eq(q.field("a"), A) : true) which is code you could write in Convex, and is what i would recommend over messing with customQuery.

SpicedOP•13mo ago

I mean i understand, its just a small challenge for me Got the hang of the custom queries although got lost after i understood custom mutations and queries

Custom FilterIf Function

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