File upload


You can customize the properties of the file upload components in the right panel, such as the displayed text, file types, upload type.

File type

You can input an array of strings to restrict the types of the files to be uploaded. The default value of file type is empty, meaning that no limitation is pre-defined. Each string value in a specified file type array should be a unique file type specifier in one of the following formats.
  • A valid case-insensitive filename extension, starting with a period character ("."), such as .png, .txt, and .pdf.
  • A valid string in MIME format without an extension.
  • String audio/* indicating "any audio file".
  • String video/* indicating "any video file".
  • String image/* indicating "any image file".
For example, when the value of file type is [".pdf", ".mp4", "image/*"], you can upload PDF files, MP4 files, and any type of image files.

Upload type

You can decide whether to upload a single file, multiple files, or a directory.

Display uploaded files

Switch on or off Show upload list to display or hide the list of the uploaded files. You can also set this property via JS code. By default, its value is "true".
The upload list presents the file names of all uploaded files in chronological order. You can also access the name of the uploaded files via the property files[index].name. When hovering your mouse over a file, the 🗑️ icon appears and you can click it to delete the corresponding file.

Parse files

Toggle Parse files and Openblocks will try to parse the uploaded file data structure into objects, arrays, or strings. You can access the parsed result via the property parsedValue. Openblocks supports parsing Excel, JSON, and CSV files. The parsing result of other types of files is null.


Under the validation tab, you can configure how many files are allowed to be uploaded, as well as the minimum and maximum size of a single file to be uploaded.

Max files

When the upload type is "Multiple" or "Directory", you can set Max files to limit the maximum number of files to upload. If the number of files to be uploaded exceeds this threshold, the latest uploaded files will replace the oldest ones.

File size

You can set the minimum and maximum size of the files to upload, using KB, MB, GB, or TB units. The default unit for file size is byte.When the size of the uploaded file exceeds the limit, you will see a global alert.

Access uploaded files

Files uploaded via the file upload component are stored in browser cache memory in base64-encoded string format. To store these files in data sources, you need to build queries to connect to databases or APIs.You can view the properties of the uploaded files in the data browser in the left pane, or access property names in {{}} or JS queries via JS code. Commonly used properties are as follows.
  • value: A list of the content of the uploaded files, encoded in base64.
  • files: A list of metadata of the uploaded files, including uid, name, type, size, and lastModified.
  • parsedValue: A list of the value of the parsed files.

Use case: Upload images to Postman Echo API

This example uploads images to Postman Echo API, and inspects the query result whether the files are sent successfully to the remote server. For more details, see Image uploader.

Upload a single file

  1. 1.
    Insert File upload component file1, and set File types and Upload type.
  2. 2.
    Insert an Image component, and set the image source as data:image;base64,{{file1.value[0]}} to preview the image cached in the browser.
  3. 3.
    Create a new query uploadSingle to send single images to Echo API. You can add a button, and bind its click event to the query. Select "POST" as the HTTP Method, and complete the Body in format {data: base64 string, name: string}, for example–{data: {{file1.value[0]}}, name: {{file1.files[0].name}}}.
  4. 4.
    Run query uploadSingle. Create a new text component to display the file name of the returned value of the query by {{Object.keys([])[0]}}. Add a new image component to view the returned image by {{Object.values([])[0]}}.

Upload multiple files

When uploading multiple files, you send an object of array to Echo API. Each item in the array should use the format {data: base64 string, name: string}. You can create a transformer multipleFileArray to convert all files to be uploaded to the target format, as shown in the following figure.
Then, create a new query uploadMultiple to upload the images to Echo API. In Body field, you can use the returned value of query multipleFileArray directly.
Run this query and check the result. The file names and the encoded content are properly accessed.
You can present the query result using a List View component.
  • Access the number of rows by the value of the fieldfiles in the query result: {{Object.keys( []).length}}.
  • Access the file names by {{Object.keys([i]}}.
  • Access the file content by {{Object.values([i]}}.