## An app with callbacks { #an-app-with-callbacks }

Let's see all this with an example.

Imagine you develop an app that allows creating invoices.

These invoices will have an `id`, `title` (optional), `customer`, and `total`.

 */
package org.codelibs.fess.app.web.api.admin.failureurl;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.app.pager.FailureUrlPager;
import org.codelibs.fess.app.service.FailureUrlService;
import org.codelibs.fess.app.web.api.ApiResult;
import org.codelibs.fess.app.web.api.ApiResult.ApiLogResponse;

 */
package org.codelibs.fess.app.web.api.admin.crawlinginfo;

import java.util.List;
import java.util.stream.Collectors;

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.codelibs.fess.app.pager.CrawlingInfoPager;
import org.codelibs.fess.app.service.CrawlingInfoService;
import org.codelibs.fess.app.web.api.ApiResult;

Ainsi, la section :

```Python
    uvicorn.run(app, host="0.0.0.0", port=8000)
```

va s'exécuter.

---

Cela ne se produira pas si vous importez ce module (fichier).

Par exemple, si vous avez un autre fichier `importer.py` qui contient :

```Python
from myapp import app

# Code supplémentaire
```

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.keymatch;

import org.codelibs.fess.app.web.api.admin.BaseSearchBody;

/**
 * Search request body for key match administration API.
 */
public class SearchBody extends BaseSearchBody {

    /**
     * Default constructor.

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.labeltype;

import org.codelibs.fess.app.web.admin.labeltype.CreateForm;

/**
 * Request body for creating label type via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.role;

import org.codelibs.fess.app.web.admin.role.CreateForm;

/**
 * Request body for creating role via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.webconfig;

import org.codelibs.fess.app.web.admin.webconfig.CreateForm;

/**
 * Request body for creating web configuration via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.boostdoc;

import org.codelibs.fess.app.web.admin.boostdoc.CreateForm;

/**
 * Request body for creating boost document via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */

 * either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */
package org.codelibs.fess.app.web.api.admin.dict.kuromoji;

import org.codelibs.fess.app.web.admin.dict.kuromoji.CreateForm;

/**
 * Request body for creating kuromoji dictionary via REST API.
 * Extends CreateForm to inherit validation and field definitions.
 */