AnzhiZhang opened a new issue, #3692: URL: https://github.com/apache/texera/issues/3692
## Problem Currently, we have many operator descriptions using `@JsonProperty(required = true)` on string fields. For example, chart operators (see #3192). https://github.com/apache/texera/blob/c7fcd9f4278f850e3c1456866ba6f25f85a8f489/core/workflow-operator/src/main/scala/edu/uci/ics/amber/operator/visualization/barChart/BarChartOpDesc.scala#L41-L70 For example, if we have this class. ```scala import com.fasterxml.jackson.annotation.JsonProperty class Test { @JsonProperty(value = "test", required = true) var test: String = "" } ``` The JSON schema will be ```json { "$schema" : "http://json-schema.org/draft-07/schema#";, "type" : "object", "additionalProperties" : false, "properties" : { "test" : { "propertyOrder" : 1, "type" : "string", "title" : "Test" } }, "required" : [ "test" ] } ``` We are using [Ajv](https://github.com/ajv-validator/ajv) in the frontend to validate JSON schema, if we test this schema in the frontend (a simple example). ```ts import Ajv from "ajv"; const ajv = new Ajv({ allErrors: true, strict: false }); const schema = { type: "object", properties: { test: { type: "string", }, }, required: ["test"], }; const json = { test: "", }; // true console.log(ajv.validate(schema, json)); const json2 = {}; // false console.log(ajv.validate(schema, json2)); ``` It only works for a real null property, not an empty string. The debug information confirms this finding. <img width="2360" height="1030" alt="Image" src="https://github.com/user-attachments/assets/9d7e1876-9dfe-40b2-862c-0dadc16fcab7"; /> <img width="2384" height="812" alt="Image" src="https://github.com/user-attachments/assets/8e0f026c-37a7-4070-8516-347589559f86"; /> ## Solution We will need to add `@NotNull` annotation from `javax.validation.constraints.NotNull` to introduce `"minLength" : 1,` requirement to the JSON Schema (https://github.com/ajv-validator/ajv/issues/885#issuecomment-441749423). ```java import com.fasterxml.jackson.annotation.JsonProperty import javax.validation.constraints.NotNull class Test { @JsonProperty(value = "test", required = true) @NotNull(message = "test cannot be empty") var test: String = "" } ``` Will generate the schema. ```json { "$schema" : "http://json-schema.org/draft-07/schema#";, "type" : "object", "additionalProperties" : false, "properties" : { "test" : { "propertyOrder" : 1, "type" : "string", "minLength" : 1, "title" : "Test" } }, "required" : [ "test" ] } ``` To test it. ```ts const schema2 = { type: "object", properties: { test: { type: "string", minLength : 1, }, }, required: ["test"], }; // false console.log(ajv.validate(schema2, json)); ``` ## Alternative Solutions To validate "empty string" (in the context of Java empty stringļ¼ which is 0 length) in Ajv, the only solution is `minLength`, a more detailed discussion can be found here (https://stackoverflow.com/a/47471462/19420247) 1. Use `javax.validation.constraints.Pattern` to validate by regex pattern, which also resolves the issue if the input string that all chars are spaces, but may require more performance and is not consistent with Java. 2. Catch error from backend. This is a workaround, as we are expecting to validate at the frontend. If we choose this solution, the validation status at the front will be valid at first, then turn to invalid. This will reflect on the Run button (flash). ## Related Issues - #3656 - #3192 - https://github.com/ajv-validator/ajv/issues/885#issuecomment-441749423 -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
