multipart/form-data

Read more about the article Create Event by Importing JSON files in Open Event Server

Create Event by Importing JSON files in Open Event Server

Apart from the usual way of creating an event in  FOSSASIA’s Orga Server project by using POST requests in Events API, another way of creating events is importing a zip file which is an archive of multiple JSON files. This way you can create a large event like FOSSASIA with lots of data related to sessions, speakers, microlocations, sponsors just by uploading JSON files to the system. Sample JSON file can be found in the open-event project of FOSSASIA. The basic workflow of importing an event and how it works is as follows: First step is similar to uploading files to the server. We need to send a POST request with a multipart form data with the zipped archive containing the JSON files. The POST request starts a celery task to start importing data from JSON files and storing them in the database. The celery task URL is returned as a response to the POST request. You can use this celery task for polling purposes to get the status. If the status is FAILURE, we get the error text along with it. If status is SUCCESS we get the resulting event data In the celery task, each JSON file is read separately and the data is stored in the db with the proper relations. Sending a GET request to the above mentioned celery task, after the task has been completed returns the event id along with the event URL. Let’s see how each of these points work in the background. Uploading ZIP containing JSON Files For uploading a zip archive instead of sending a JSON data in the POST request we send a multipart form data. The multipart/form-data format of sending data allows an entire file to be sent as a data in the POST request along with the relevant file informations. One can know about various form content types here . An example cURL request looks something like this: curl -H "Authorization: JWT <access token>" -X POST -F 'file=@event1.zip' http://localhost:5000/v1/events/import/json The above cURL request uploads a file event1.zip from your current directory with the key as ‘file’ to the endpoint /v1/events/import/json. The user uploading the feels needs to have a JWT authentication key or in other words be logged in to the system as it is necessary to create an event. @import_routes.route('/events/import/<string:source_type>', methods=['POST']) @jwt_required() def import_event(source_type): if source_type == 'json': file_path = get_file_from_request(['zip']) else: file_path = None abort(404) from helpers.tasks import import_event_task task = import_event_task.delay(email=current_identity.email, file=file_path, source_type=source_type, creator_id=current_identity.id) # create import job create_import_job(task.id) # if testing if current_app.config.get('CELERY_ALWAYS_EAGER'): TASK_RESULTS[task.id] = { 'result': task.get(), 'state': task.state } return jsonify( task_url=url_for('tasks.celery_task', task_id=task.id) ) After the request is received we check if a file exists in the key ‘file’ of the form-data. If it is there, we save the file and get the path to the saved file. Then we send this path over to the celery task and run the task with the .delay() function of celery. After the celery task is started, the corresponding data about the import job is…

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Read more about the article Uploading Files via APIs in the Open Event Server

Uploading Files via APIs in the Open Event Server

There are two file upload endpoints. One is endpoint for image upload and the other is for all other files being uploaded. The latter endpoint is to be used for uploading files such as slides, videos and other presentation materials for a session. So, in FOSSASIA’s Orga Server project, when we need to upload a file, we make an API request to this endpoint which is turn uploads the file to the server and returns back the url for the uploaded file. We then store this url for the uploaded file to the database with the corresponding row entry. Sending Data The endpoint /upload/file  accepts a POST request, containing a multipart/form-data payload. If there is a single file that is uploaded, then it is uploaded under the key “file” else an array of file is sent under the key “files”. A typical single file upload cURL request would look like this: curl -H “Authorization: JWT <key>” -F file=@file.pdf -x POST http://localhost:5000/v1/upload/file A typical multi-file upload cURL request would look something like this: curl -H “Authorization: JWT <key>” -F files=@file1.pdf -F files=@file2.pdf -x POST http://localhost:5000/v1/upload/file Thus, unlike other endpoints in open event orga server project, we don’t send a json encoded request. Instead it is a form data request. Saving Files We use different services such as S3, google cloud storage and so on for storing the files depending on the admin settings as decided by the admin of the project. One can even ask to save the files locally by passing a GET parameter force_local=true. So, in the backend we have 2 cases to tackle- Single File Upload and Multiple Files Upload. Single File Upload if 'file' in request.files: files = request.files['file'] file_uploaded = uploaded_file(files=files) if force_local == 'true': files_url = upload_local( file_uploaded, UPLOAD_PATHS['temp']['event'].format(uuid=uuid.uuid4()) ) else: files_url = upload( file_uploaded, UPLOAD_PATHS['temp']['event'].format(uuid=uuid.uuid4()) ) We get the file, that is to be uploaded using request.files[‘file’] with the key as ‘file’ which was used in the payload. Then we use the uploaded_file() helper function to convert the file data received as payload into a proper file and store it in a temporary storage. After this, if force_local is set as true, we use the upload_local helper function to upload it to the local storage, i.e. the server where the application is hosted, else we use whatever service is set by the admin in the admin settings. In uploaded_file() function of helpers module, we extract the filename and the extension of the file from the form-data payload. Then we check if the suitable directory already exists. If it doesn’t exist, we create a new directory and then save the file in the directory extension = files.filename.split('.')[1] filename = get_file_name() + '.' + extension filedir = current_app.config.get('BASE_DIR') + '/static/uploads/' if not os.path.isdir(filedir): os.makedirs(filedir) file_path = filedir + filename files.save(file_path) After that the upload function gets the settings key for either s3 or google storage and then uses the corresponding functions to upload this temporary file to the storage. Multiple File Upload elif 'files[]' in request.files:…

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