feat: only get template fields once selectedfeat/template-field-extraction-improvements

In order to improve the performance and flow of creating a new file
from a template, the `setFields` method will be deprecated and we
instead use a new property, `setFieldsUrl`, which allows apps to
specify an endpoint for extracting the template fields. This endpoint
is used by the template picker to request the fields only once the
user has selected a template, instead of fetching all template fields
before opening and causing a terribly slow experience.

Signed-off-by: Elizabeth Danzberger <lizzy7128@tutanota.de>

4 files changed, 44 insertions, 6 deletions

diff --git a/apps/files/lib/ResponseDefinitions.php b/apps/files/lib/ResponseDefinitions.php
index c5d094e7bd8..f10edd3216c 100644
--- a/apps/files/lib/ResponseDefinitions.php
+++ b/apps/files/lib/ResponseDefinitions.php
@@ -46,6 +46,7 @@ namespace OCA\Files;
  *      hasPreview: bool,
  *      previewUrl: ?string,
  *      fields: list<FilesTemplateField>,
+ * 		fieldsUrl: ?string,
  *  }
  *
  * @psalm-type FilesTemplateFileCreator = array{
diff --git a/apps/files/src/services/Templates.js b/apps/files/src/services/Templates.js
index 3a0a0fdb809..cd75d105fd5 100644
--- a/apps/files/src/services/Templates.js
+++ b/apps/files/src/services/Templates.js
@@ -11,6 +11,11 @@ export const getTemplates = async function() {
 	return response.data.ocs.data
 }
 
+export const getTemplateFields = async function(fieldsUrl) {
+	const response = await axios.get(fieldsUrl)
+	return response.data.ocs.data
+}
+
 /**
  * Create a new file from a specified template
  *
diff --git a/apps/files/src/views/TemplatePicker.vue b/apps/files/src/views/TemplatePicker.vue
index 15286a220e9..12226e7b07b 100644
--- a/apps/files/src/views/TemplatePicker.vue
+++ b/apps/files/src/views/TemplatePicker.vue
@@ -57,7 +57,7 @@ import { translate as t } from '@nextcloud/l10n'
 import { generateRemoteUrl } from '@nextcloud/router'
 import { normalize, extname, join } from 'path'
 import { defineComponent } from 'vue'
-import { createFromTemplate, getTemplates } from '../services/Templates.js'
+import { createFromTemplate, getTemplates, getTemplateFields } from '../services/Templates.js'
 
 import NcEmptyContent from '@nextcloud/vue/components/NcEmptyContent'
 import NcModal from '@nextcloud/vue/components/NcModal'
@@ -215,7 +215,7 @@ export default defineComponent({
 			}
 		},
 
-		async createFile(templateFields) {
+		async createFile(templateFields = []) {
 			const currentDirectory = new URL(window.location.href).searchParams.get('dir') || '/'
 
 			// If the file doesn't have an extension, add the default one
@@ -274,14 +274,33 @@ export default defineComponent({
 		},
 
 		async onSubmit() {
-			if (this.selectedTemplate?.fields?.length > 0) {
+			const fieldsUrl = this.selectedTemplate?.fieldsUrl
+
+			if (!fieldsUrl) {
+				this.loading = true
+				return await this.createFile()
+			}
+
+			try {
+				const fields = await getTemplateFields(fieldsUrl)
+
+				if (fields.length < 1) {
+					this.loading = true
+					return await this.createFile()
+				}
+
 				spawnDialog(TemplateFiller, {
-					fields: this.selectedTemplate.fields,
 					onSubmit: this.createFile,
+					fields,
 				})
-			} else {
+			} catch (error) {
+				logger.error('Error while extracting fields from template', { error })
+				showError(t('files', 'Could not extract fields from template'))
+
+				// If fetching the template fields fails, we can create
+				// a file anyway without any fields filled
 				this.loading = true
-				await this.createFile()
+				await this.createFile([])
 			}
 		},
 	},
diff --git a/lib/public/Files/Template/Template.php b/lib/public/Files/Template/Template.php
index 7f01c2afa48..b3ecbb91073 100644
--- a/lib/public/Files/Template/Template.php
+++ b/lib/public/Files/Template/Template.php
@@ -26,6 +26,8 @@ final class Template implements \JsonSerializable {
 	private $previewUrl = null;
 	/** @var list<Field> */
 	private $fields = [];
+	/** @var string|null */
+	private $fieldsUrl = null;
 
 	/**
 	 * @since 21.0.0
@@ -51,6 +53,7 @@ final class Template implements \JsonSerializable {
 	}
 
 	/**
+	 * @deprecated
 	 * @param list<Field> $fields
 	 * @since 30.0.0
 	 */
@@ -59,6 +62,14 @@ final class Template implements \JsonSerializable {
 	}
 
 	/**
+	 * @param string $fieldsUrl
+	 * @since 32.0.0
+	 */
+	public function setFieldsUrl(string $fieldsUrl): void {
+		$this->fieldsUrl = $fieldsUrl;
+	}
+
+	/**
 	 * @return array{
 	 *     templateType: string,
 	 *     templateId: string,
@@ -72,6 +83,7 @@ final class Template implements \JsonSerializable {
 	 *     type: string,
 	 *     hasPreview: bool,
 	 *     previewUrl: ?string,
+	 *     fieldsUrl: ?string,
 	 *     fields: list<array{
 	 *         index: string,
 	 *         type: string,
@@ -99,6 +111,7 @@ final class Template implements \JsonSerializable {
 			'hasPreview' => $this->hasPreview,
 			'previewUrl' => $this->previewUrl,
 			'fields' => array_map(static fn (Field $field) => $field->jsonSerialize(), $this->fields),
+			'fieldsUrl' => $this->fieldsUrl,
 		];
 	}
 }