# class: FormData
* since: v1.18
* langs: java, csharp

The [FormData] is used create form data that is sent via [APIRequestContext].

```java
import com.microsoft.playwright.options.FormData;
...
FormData form = FormData.create()
    .set("firstName", "John")
    .set("lastName", "Doe")
    .set("age", 30);
page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
```

## method: FormData.append
* since: v1.43
- returns: <[FormData]>

Appends a new value onto an existing key inside a FormData object, or adds the key if it
does not already exist. File values can be passed either as `Path` or as `FilePayload`.
Multiple fields with the same name can be added.

The difference between [`method: FormData.set`] and [`method: FormData.append`] is that if the specified key already exists,
set() will overwrite all existing values with the new one, whereas append() will append
the new value onto the end of the existing set of values.

```java
import com.microsoft.playwright.options.FormData;
...
FormData form = FormData.create()
    // Only name and value are set.
    .append("firstName", "John")
    // Name and value are set, filename and Content-Type are inferred from the file path.
    .append("attachment", Paths.get("pic.jpg"))
    // Name, value, filename and Content-Type are set.
    .append("attachment", new FilePayload("table.csv", "text/csv", Files.readAllBytes(Paths.get("my-tble.csv"))));
page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
```

```csharp
var multipart = Context.APIRequest.CreateFormData();
// Only name and value are set.
multipart.Append("firstName", "John");
// Name, value, filename and Content-Type are set.
multipart.Append("attachment", new FilePayload()
{
    Name = "pic.jpg",
    MimeType = "image/jpeg",
    Buffer = File.ReadAllBytes("john.jpg")
});
// Name, value, filename and Content-Type are set.
multipart.Append("attachment", new FilePayload()
{
    Name = "table.csv",
    MimeType = "text/csv",
    Buffer = File.ReadAllBytes("my-tble.csv")
});
await Page.APIRequest.PostAsync("https://localhost/submit", new() { Multipart = multipart });
```

### param: FormData.append.name
* since: v1.43
- `name` <[string]>

Field name.

### param: FormData.append.value
* since: v1.43
- `value` <[string]|[boolean]|[int]|[Path]|[Object]>
  - `name` <[string]> File name
  - `mimeType` <[string]> File type
  - `buffer` <[Buffer]> File content

Field value.

### param: FormData.append.value
* since: v1.43
* langs: csharp
- `value` <[string]|[boolean]|[int]|[Object]>
  - `name` <[string]> File name
  - `mimeType` <[string]> File type
  - `buffer` <[Buffer]> File content

Field value.

## method: FormData.create
* since: v1.18
* langs: java
- returns: <[FormData]>

Creates new instance of [FormData].

## method: FormData.set
* since: v1.18
- returns: <[FormData]>

Sets a field on the form. File values can be passed either as `Path` or as `FilePayload`.

```java
import com.microsoft.playwright.options.FormData;
...
FormData form = FormData.create()
    // Only name and value are set.
    .set("firstName", "John")
    // Name and value are set, filename and Content-Type are inferred from the file path.
    .set("profilePicture1", Paths.get("john.jpg"))
    // Name, value, filename and Content-Type are set.
    .set("profilePicture2", new FilePayload("john.jpg", "image/jpeg", Files.readAllBytes(Paths.get("john.jpg"))))
    .set("age", 30);
page.request().post("http://localhost/submit", RequestOptions.create().setForm(form));
```

```csharp
var multipart = Context.APIRequest.CreateFormData();
// Only name and value are set.
multipart.Set("firstName", "John");
// Name, value, filename and Content-Type are set.
multipart.Set("profilePicture", new FilePayload()
{
    Name = "john.jpg",
    MimeType = "image/jpeg",
    Buffer = File.ReadAllBytes("john.jpg")
});
multipart.Set("age", 30);
await Page.APIRequest.PostAsync("https://localhost/submit", new() { Multipart = multipart });
```

### param: FormData.set.name
* since: v1.18
- `name` <[string]>

Field name.

### param: FormData.set.value
* since: v1.18
- `value` <[string]|[boolean]|[int]|[Path]|[Object]>
  - `name` <[string]> File name
  - `mimeType` <[string]> File type
  - `buffer` <[Buffer]> File content

Field value.

### param: FormData.set.value
* since: v1.18
* langs: csharp
- `value` <[string]|[boolean]|[int]|[Object]>
  - `name` <[string]> File name
  - `mimeType` <[string]> File type
  - `buffer` <[Buffer]> File content

Field value.
