Adding validation to the SQL relationship creation modal.

packages/builder/src/pages/builder/app/[application]/data/datasource/[selectedDatasource]/CreateEditRelationship/CreateEditRelationship.svelte

@@ -1,8 +1,9 @@
 <script>
   import { RelationshipTypes } from "constants/backend"
-  import { Button, Input, ModalContent, Select, Detail } from "@budibase/bbui"
+  import { Button, Input, ModalContent, Select, Detail, Body } from "@budibase/bbui"
   import { tables } from "stores/backend"
   import { uuid } from "builderStore/uuid"
+  import { writable } from "svelte/store"
 
   export let save
   export let datasource
@@ -14,16 +15,57 @@
   let originalFromName = fromRelationship.name,
     originalToName = toRelationship.name
 
-  function isValid(relationship) {
-    if (
-      relationship.relationshipType === RelationshipTypes.MANY_TO_MANY &&
-      !relationship.through
-    ) {
+  function inSchema(table, prop, ogName) {
+    if (!table || !prop || prop === ogName) {
       return false
     }
-    return (
-      relationship.name && relationship.tableId && relationship.relationshipType
-    )
+    const keys = Object.keys(table.schema).map(key => key.toLowerCase())
+    return keys.indexOf(prop.toLowerCase()) !== -1
+  }
+
+  const touched = writable({})
+
+  function checkForErrors(fromTable, toTable, throughTable, fromRelate, toRelate) {
+    const isMany = fromRelate.relationshipType === RelationshipTypes.MANY_TO_MANY
+    const tableNotSet = "Please specify a table"
+    const errors = {}
+    if ($touched.from && !fromTable) {
+      errors.from = tableNotSet
+    }
+    if ($touched.to && !toTable) {
+      errors.to = tableNotSet
+    }
+    if ($touched.through && isMany && !fromRelate.through) {
+      errors.through = tableNotSet
+    }
+    if ($touched.foreign && !isMany && !fromRelate.fieldName) {
+      errors.foreign = "Please pick the foreign key"
+    }
+    const colNotSet = "Please specify a column name"
+    if ($touched.fromCol && !fromRelate.name) {
+      errors.fromCol = colNotSet
+    }
+    if ($touched.toCol && !toRelate.name) {
+      errors.toCol = colNotSet
+    }
+    const tableError = "From/to/through tables must be different"
+    if (fromTable && (fromTable === toTable || fromTable === throughTable)) {
+      errors.from = tableError
+    }
+    if (toTable && (toTable === fromTable || toTable === throughTable)) {
+      errors.to = tableError
+    }
+    if (throughTable && (throughTable === fromTable || throughTable === toTable)) {
+      errors.through = tableError
+    }
+    const colError = "Column name cannot be an existing column"
+    if (inSchema(fromTable, fromRelate.name, originalFromName)) {
+      errors.fromCol = colError
+    }
+    if (inSchema(toTable, toRelate.name, originalToName)) {
+      errors.toCol = colError
+    }
+    return errors
   }
 
   $: tableOptions = plusTables.map(table => ({
@@ -33,7 +75,8 @@
   $: fromTable = plusTables.find(table => table._id === toRelationship?.tableId)
   $: toTable = plusTables.find(table => table._id === fromRelationship?.tableId)
   $: through = plusTables.find(table => table._id === fromRelationship?.through)
-  $: valid = toTable && fromTable && isValid(fromRelationship)
+  $: errors = checkForErrors(fromTable, toTable, through, fromRelationship, toRelationship)
+  $: valid = Object.keys(errors).length === 0 && Object.keys($touched).length !== 0
   $: linkTable = through || toTable
   $: relationshipTypes = [
     {
@@ -155,32 +198,44 @@
   <Select
     label="Select from table"
     options={tableOptions}
+    on:change={() => ($touched.from = true)}
+    bind:error={errors.from}
     bind:value={toRelationship.tableId}
   />
   <Select
     label={"Select to table"}
     options={tableOptions}
+    on:change={() => ($touched.to = true)}
+    bind:error={errors.to}
     bind:value={fromRelationship.tableId}
   />
   {#if fromRelationship?.relationshipType === RelationshipTypes.MANY_TO_MANY}
     <Select
       label={"Through"}
       options={tableOptions}
+      on:change={() => ($touched.through = true)}
+      bind:error={errors.through}
       bind:value={fromRelationship.through}
     />
   {:else if toTable}
     <Select
       label={`Foreign Key (${toTable?.name})`}
       options={Object.keys(toTable?.schema)}
+      on:change={() => ($touched.foreign = true)}
+      bind:error={errors.foreign}
       bind:value={fromRelationship.fieldName}
     />
   {/if}
   <div class="headings">
     <Detail>Column names</Detail>
   </div>
-  <Input label="From table column" bind:value={fromRelationship.name} />
-  <Input label="To table column" bind:value={toRelationship.name} />
+  <Body>
+    Budibase manages SQL relationships as a new column in the table, please provide a name for these columns.
+  </Body>
+  <Input on:blur={() => ($touched.fromCol = true)} bind:error={errors.fromCol} label="From table column" bind:value={fromRelationship.name} />
+  <Input on:blur={() => ($touched.toCol = true)} bind:error={errors.toCol} label="To table column" bind:value={toRelationship.name} />
   <div slot="footer">
+
     {#if originalFromName != null}
       <Button warning text on:click={deleteRelationship}>Delete</Button>
     {/if}