Use ng select for multiselect

client/src/app/shared/shared-forms/select/select-checkbox.component.ts

@@ -0,0 +1,75 @@
+import { Component, Input, forwardRef } from '@angular/core'
+import { NG_VALUE_ACCESSOR, ControlValueAccessor } from '@angular/forms'
+import { SelectOptionsItem } from './select-options.component'
+
+export type ItemSelectCheckboxValue = { id?: string | number, group?: string } | string
+
+@Component({
+  selector: 'my-select-checkbox',
+  styleUrls: [ './select-shared.component.scss', 'select-checkbox.component.scss' ],
+  templateUrl: './select-checkbox.component.html',
+  providers: [
+    {
+      provide: NG_VALUE_ACCESSOR,
+      useExisting: forwardRef(() => SelectCheckboxComponent),
+      multi: true
+    }
+  ]
+})
+export class SelectCheckboxComponent implements ControlValueAccessor {
+  @Input() availableItems: SelectOptionsItem[] = []
+  @Input() selectedItems: ItemSelectCheckboxValue[] = []
+  @Input() selectableGroup: boolean
+  @Input() selectableGroupAsModel: boolean
+  @Input() maxSelectedItems: number
+
+  propagateChange = (_: any) => { /* empty */ }
+
+  writeValue (items: ItemSelectCheckboxValue[]) {
+    if (Array.isArray(items)) {
+      this.selectedItems = items.map(i => {
+        if (typeof i === 'string' || typeof i === 'number') {
+          return i + ''
+        }
+
+        if (i.group) {
+          return { group: i.group }
+        }
+
+        return { id: i.id + '' }
+      })
+    } else {
+      this.selectedItems = items
+    }
+
+    this.propagateChange(this.selectedItems)
+  }
+
+  registerOnChange (fn: (_: any) => void) {
+    this.propagateChange = fn
+  }
+
+  registerOnTouched () {
+    // Unused
+  }
+
+  onModelChange () {
+    this.propagateChange(this.selectedItems)
+  }
+
+  compareFn (item: SelectOptionsItem, selected: ItemSelectCheckboxValue) {
+    if (typeof selected === 'string') {
+      return item.id === selected
+    }
+
+    if (this.selectableGroup && item.group && selected.group) {
+      return item.group === selected.group
+    }
+
+    if (selected.id && item.id) {
+      return item.id === selected.id
+    }
+
+    return false
+  }
+}