Skip processors on error

[TravisS25]

It would be nice to have the ability to skip processors from running if any errors have occurred. This is mainly regarding the struct schema when using the TestFunc(). My thinking with the TestFunc() on a struct schema is that it should only run if all fields within struct schema have passed validation. This would allow a user to confidently do additional validation between fields without have to "re-check" if those fields are valid.

[Oudwins]

Internally zog already keeps track of if an error has happened inside the ctx. It's just not exposed.

So we can so this in many different ways. Would you mind sharing a little bit more about your specific use case? It will help me determine what the best api for this would be.

[TravisS25]

Sure. Below is a snippet of what I am currently working on.

var (
  db *sql.DB
)
...
z.Struct(z.Shape{
		"areaID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val *int, zctx z.Ctx) bool {
				// Main point is that I check if areaID exists in database and return true if it does
				// and false if it does not

				...
				err = db.QueryRow("SELECT area.id FROM area WHERE id = 1")
				if err != nil {
					if err == sql.ErrNoRows {
						zctx.AddIssue(zctx.Issue().SetMessage("Does not exist"))
						return false
					}
				}
				...

				return true
			}),
		"cityID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val any, zctx z.Ctx) bool {
				// Main point is that I check if cityID exists in database and return true if it does
				// and false if it does not

				...
				err = db.QueryRow("SELECT city.id FROM city WHERE id = 1")
				if err != nil {
					if err == sql.ErrNoRows {
						zctx.AddIssue(zctx.Issue().SetMessage("Does not exist"))
						return false
					}
				}
				...

				return true
			}),
	}).TestFunc(func(val any, zctx z.Ctx) bool {

		// Here I would like to check that areaID and cityID doesn't exist in my join table yet
		// but TestFunc runs no matter and there is no way to determine what fields have 
		// errored out currently in the context so I would have to re-query the ids to make sure they are valid.  
		// Would be nice if we could choose for this not to run on error or at the very least, be able to see
		// if any or what fields have failed from the context to work around things
		...
		return true
	})

Given the above, it would be nice to have something like:

z.Struct(z.Shape{
		"areaID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val *int, zctx z.Ctx) bool {
				...
			}),
		"cityID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val any, zctx z.Ctx) bool {
				...
			}),
	}).TestFunc(func(val any, zctx z.Ctx) bool {
	// This never gets run
          ...
	}).SkipProcessorsOnError() <--- Where this sets internal flag to skip processors from even running if 
errors occur as there is not point in continuing to process things

Or like you mentioned, exposing errors through ctx

z.Struct(z.Shape{
		"areaID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val *int, zctx z.Ctx) bool {
				...
			}),
		"cityID": z.Int().
			Required(z.Message(zconst.IssueCodeRequired)).
			TestFunc(func(val any, zctx z.Ctx) bool {
				...
			}),
	}).TestFunc(func(val any, zctx z.Ctx) bool {
         // In this case, not point in continuing 
         if len(zctx.Errors) > 0{
             return false
          }
          ...
          return true
	})

[Oudwins]

Okay got it. This was exactly what I was thinking would be the issue. Thank you for clarifying! Let me think a little bit about it and come up with a solution for you!

[Oudwins]

Hey! Thinking about it for a bit. I'm fairly certain that this will be handled by the context. In fact, Zog might expose the entire issues array in the future. But there are a few other problems I would like to look into before commiting to an API for this.

So, if you need this now I would recommend you use this method on the context

This will probably be changed at some point but I can say with like 95% confidence that it wll just be a one line change. Most likely one of these:

// option 1
ctx.HasErrored() -> len(ctx.Issues()) > 0
// option 2
ctx.HasErrored -> ctx.HasIssue()

I also want to work on an API for interacting from errors from other sibling/child schemas. But that will come later as I'm currently working on compilation/codegen