custom fields have been added to the documents

backend/modules/document/views/document-field-value/_form.php

@@ -0,0 +1,40 @@
+<?php
+
+use backend\modules\document\models\Document;
+use backend\modules\document\models\DocumentField;
+use yii\helpers\ArrayHelper;
+use yii\helpers\Html;
+use yii\widgets\ActiveForm;
+
+/* @var $this yii\web\View */
+/* @var $model backend\modules\document\models\DocumentFieldValue */
+/* @var $form yii\widgets\ActiveForm */
+/* @var $fromDocument bool */
+?>
+
+<div class="document-field-value-form">
+
+    <?php $form = ActiveForm::begin(); ?>
+
+    <?php
+        if (!$fromDocument) {
+            echo $form->field($model, 'document_field_id')->dropDownList(
+                ArrayHelper::map(DocumentField::find()->all(), 'id', 'title'),
+                ['prompt' => '...']
+            );
+            echo $form->field($model, 'document_id')->dropDownList(
+                ArrayHelper::map(Document::find()->all(), 'id', 'title'),
+                ['prompt' => '...']
+            );
+        }
+    ?>
+
+    <?= $form->field($model, 'value')->textInput(['maxlength' => true]) ?>
+
+    <div class="form-group">
+        <?= Html::submitButton('Save', ['class' => 'btn btn-success']) ?>
+    </div>
+
+    <?php ActiveForm::end(); ?>
+
+</div>