Add fallback-content-type property

docs/configuration.md

@@ -1006,12 +1006,16 @@ Display a widget provided by an external source (3rd party). If you want to lear
 | Name | Type | Required | Default |
 | ---- | ---- | -------- | ------- |
 | url | string | yes | |
+| fallback-content-type | string | no | |
 | allow-potentially-dangerous-html | boolean | no | false |
 | parameters | key & value | no | |
 
 ##### `url`
 The URL of the extension.
 
+##### `fallback-content-type`
+Optionally specify the fallback content type of the extension if the URL does not return a valid `Widget-Content-Type` header. Currently the only supported value for this property is `html`.
+
 ##### `allow-potentially-dangerous-html`
 Whether to allow the extension to display HTML.
 

internal/feed/extension.go

@@ -28,6 +28,7 @@ const (
 
 type ExtensionRequestOptions struct {
 	URL                 string            `yaml:"url"`
+	FallbackContentType string            `yaml:"fallback-content-type"`
 	Parameters          map[string]string `yaml:"parameters"`
 	AllowHtml           bool              `yaml:"allow-potentially-dangerous-html"`
 }
@@ -87,9 +88,13 @@ func FetchExtension(options ExtensionRequestOptions) (Extension, error) {
 
 	contentType, ok := ExtensionStringToType[response.Header.Get(ExtensionHeaderContentType)]
 
+	if !ok {
+		contentType, ok = ExtensionStringToType[options.FallbackContentType]
+
 		if !ok {
 			contentType = ExtensionContentUnknown
 		}
+	}
 
 	extension.Content = convertExtensionContent(options, body, contentType)
 

internal/widget/extension.go

@@ -14,6 +14,7 @@ import (
 type Extension struct {
 	widgetBase          `yaml:",inline"`
 	URL                 string            `yaml:"url"`
+	FallbackContentType string            `yaml:"fallback-content-type"`
 	Parameters          map[string]string `yaml:"parameters"`
 	AllowHtml           bool              `yaml:"allow-potentially-dangerous-html"`
 	Extension           feed.Extension    `yaml:"-"`
@@ -39,6 +40,7 @@ func (widget *Extension) Initialize() error {
 func (widget *Extension) Update(ctx context.Context) {
 	extension, err := feed.FetchExtension(feed.ExtensionRequestOptions{
 		URL:                 widget.URL,
+		FallbackContentType: widget.FallbackContentType,
 		Parameters:          widget.Parameters,
 		AllowHtml:           widget.AllowHtml,
 	})