Implement before-submit validation (broken, crashing)

2 files changed, 94 insertions, 5 deletions

diff --git a/src/components/Question.tsx b/src/components/Question.tsx
index 81c43b2..df9d18e 100644
--- a/src/components/Question.tsx
+++ b/src/components/Question.tsx
@@ -19,6 +19,7 @@ const skip_normal_state: Array<QuestionType> = [
 export type QuestionProp = {
     question: Question,
     public_state: Map<string, string | boolean | null>,
+    scroll_ref: React.RefObject<HTMLDivElement>
 }
 
 class RenderedQuestion extends React.Component<QuestionProp> {
@@ -146,6 +147,66 @@ class RenderedQuestion extends React.Component<QuestionProp> {
         this.setPublicState("value", event.target.value);
     }
 
+    validateField(): void {
+        if (!this.props.question.required) {
+            return;
+        }
+
+        let invalid = false;
+        const options: string | string[] = this.props.question.data["options"];
+        switch (this.props.question.type) {
+            case QuestionType.TextArea:
+                if (this.props.public_state.get("value") === "") {
+                    invalid = true;
+                }
+                break;
+            
+            case QuestionType.ShortText:
+                if (this.props.public_state.get("value") === "") {
+                    invalid = true;
+                }
+                break;
+            
+            case QuestionType.Select:
+                if (!this.props.public_state.get("value")) {
+                    invalid = true;
+                }
+                break;
+
+            case QuestionType.Range:
+                if (!this.props.public_state.get("value")) {
+                    invalid = true;
+                }
+                break;
+
+            case QuestionType.Radio:
+                if (!this.props.public_state.get("value")) {
+                    invalid = true;
+                }
+                break;
+
+            case QuestionType.Checkbox:
+                if (typeof options !== "string") {
+                    const keys: string[] = [];
+                    options.forEach((val, index) => {
+                        keys.push(`${("000" + index).slice(-4)}. ${val}`);
+                    });
+                    if (keys.every(v => !this.props.public_state.get(v))) {
+                        invalid = true;
+                    }
+                }
+                break;
+        }
+
+        if (invalid) {
+            this.setPublicState("error", "Field must be filled.");
+            this.setPublicState("valid", false);
+        } else {
+            this.setPublicState("error", "");
+            this.setPublicState("valid", true);
+        }
+    }
+
     componentDidMount(): void {
         // Initialize defaults for complex and nested fields
         const options: string | string[] = this.props.question.data["options"];
@@ -228,7 +289,7 @@ class RenderedQuestion extends React.Component<QuestionProp> {
                 error = rawError;
             }
 
-            return <div>
+            return <div ref={this.props.scroll_ref}>
                 <h2 css={[selectable, requiredStarStyles]}>
                     {question.name}<span className={question.required ? "required" : ""}>*</span>
                 </h2>
diff --git a/src/pages/FormPage.tsx b/src/pages/FormPage.tsx
index c49b9fd..6c7cad2 100644
--- a/src/pages/FormPage.tsx
+++ b/src/pages/FormPage.tsx
@@ -2,7 +2,7 @@
 import { jsx, css } from "@emotion/react";
 import { Link } from "react-router-dom";
 
-import React, { SyntheticEvent, useEffect, useState } from "react";
+import React, { SyntheticEvent, useEffect, useState, createRef, RefObject } from "react";
 import { useParams } from "react-router";
 
 import HeaderBar from "../components/HeaderBar";
@@ -13,6 +13,7 @@ import ScrollToTop from "../components/ScrollToTop";
 import { Form, FormFeatures, getForm } from "../api/forms";
 import colors from "../colors";
 import { unselectable }  from "../commonStyles";
+import { Question } from "../api/question";
 
 
 interface PathParams {
@@ -167,12 +168,36 @@ function FormPage(): JSX.Element {
         return <Loading/>;
     }
 
-    const questions = form.questions.map((question, index) => {
-        return <RenderedQuestion question={question} public_state={new Map()} key={index + Date.now()}/>;
+    const questionsMap: Map<string, JSX.Element> = new Map();
+    form.questions.map((question, index) => {
+        questionsMap.set(question.id, <RenderedQuestion ref={createRef<RenderedQuestion>()} scroll_ref={createRef<HTMLDivElement>()} question={question} public_state={new Map()} key={index + Date.now()}/>);
     });
 
     function handleSubmit(event: SyntheticEvent) {
-        questions.forEach(prop => {
+        // Client-side required validation
+        const invalidFieldIds: string[] = [];
+        questionsMap.forEach((prop, id) => {
+            const question: Question = prop.props.question;
+            if (!question.required) {
+                return;
+            }
+
+            prop.ref.current.validateField();
+            // In case when field is invalid, add this to invalid fields list.
+            if (prop.props.public_state.get("valid") === false) {
+                invalidFieldIds.push(id);
+            }
+        });
+
+        if (invalidFieldIds.length) {
+            const firstErrored = questionsMap.get(invalidFieldIds[0]);
+            if (firstErrored !== undefined) {
+                firstErrored.props.scroll_ref.current.scrollIntoView({ behavior: "smooth", block: "center" });
+            }
+            return;
+        }
+
+        questionsMap.forEach(prop => {
             const question = prop.props.question;
 
             // TODO: Parse input from each question, and submit
@@ -192,6 +217,9 @@ function FormPage(): JSX.Element {
         closed_header = <div css={closedHeaderStyles}>This form is now closed. You will not be able to submit your response.</div>;
     }
 
+    const questions: JSX.Element[] = [];
+    questionsMap.forEach(val => questions.push(val));
+
     return (
         <div>
             <HeaderBar title={form.name} description={form.description}/>