options.md

Options

STAC Browser exposes a wide variety of configuration options. The following options can be provided in various ways to STAC Browser, either when running it or when building it.

The following ways to set config options are possible:

• Customize the config file (recommended)
• Additionally, some options can be provided through the root catalog for consistency across multiple deployments (recommended)
• Append them to the CLI command as parameter (see Get Started for an example)
• Set environment variables, all options need a SB_ prefix. So you could for example set the catalog URL via the environment variable SB_catalogUrl.
• Optionally, you can also set options after the build, basically at "runtime". Enable this by removing the <!-- and --> around the <script defer="defer" src="./config.js"></script> in the public/index.html. Then run the build procedure and after completion, you can fill the dist/config.js with any options that you want to customize.

The following options are available:

• catalogUrl
• catalogTitle
• allowExternalAccess
• allowedDomains
• apiCatalogPriority
• detectLocaleFromBrowser
• storeLocale
• locale
• fallbackLocale
• supportedLocales
• historyMode
• pathPrefix
• stacProxyUrl
• buildTileUrlTemplate
• useTileLayerAsFallback
• displayGeoTiffByDefault
• redirectLegacyUrls
• itemsPerPage
• maxPreviewsOnMap
• cardViewMode
• cardViewSort
• showKeywordsInItemCards
• showKeywordsInCatalogCards
• showThumbnailsAsAssets
• defaultThumbnailSize
• crossOriginMedia
• requestHeaders
• requestQueryParameters
• authConfig
• preprocessSTAC

catalogUrl

The URL of the catalog to show by default.

The URL provided here must match exactly with the href that is provided as self link in the response body of the URL.

This is usually a URL provided as string, but in the config file you can also provide a function without parameters that returns the URL, e.g. () => window.origin.toString().replace(/\/?$/, '/').

If catalogUrl is empty or set to null STAC Browser switches to a mode where it defaults to a screen where you can either insert a catalog URL or select a catalog from stacindex.org.

catalogTitle

The default title shown if no title can be read from the root STAC catalog.

allowExternalAccess

This allows or disallows loading and browsing external STAC data. External STAC data is any data that is not a children of the given catalogUrl. Must be set to true if a catalogUrl is not given as otherwise you won't be able to browse anything.

allowedDomains

You can list additional domains (e.g. example.com) that private data is sent to, e.g. authentication data. This applies to query paramaters and request headers.

apiCatalogPriority

For STAC APIs there are two potential sources for catalogs and collections:

1. Collections loaded from /collections and detected through the data link
2. Childs (i.e. Catalogs and Collections) loaded from various sources and detected through the child links

By default, STAC Browser loads and shows data from both sources, but tries to eliminate duplicates. If you only want to show the data from one of the sources, you can use this option. The following options are available:

• collections: Show only collections
• childs: Show only children
• null: Default behavior

detectLocaleFromBrowser

If set to true, tries to detect the preferred language of the user from the Browser. Otherwise, defaults to the language set for locale.

storeLocale

If set to true (default), stores the locale selected by the user in the storage of the browser. If set to false, doesn't store the locale across browser sessions.

Depending on the browser settings, this may store in either:

• localeStorage
• sessionStorage
• cookies

In some countries this may have implications with regards to GDPR etc. If you want to avoid this, disable this setting.

locale

The default language to use for STAC Browser, defaults to en (English). The language given here must be present in supportedLocales.

fallbackLocale

The language to use if individual phrases are not available in the default language, defaults to en (English). The language given here must be present in supportedLocales.

supportedLocales

A list of languages to show in the STAC Browser UI. The languages given here must have a corresponding JS and JSON file in the src/locales folder, e.g. provide en (English) for the files in src/locales/en.

In CLI, please provide the languages separated by a space, e.g. --supportedLocales en de fr it

Please note that only left-to-right languages have been tested. I'd need help to test support for right-to-left languages.

historyMode

build-only option

history

STAC Browser defaults to history mode (value history in the config file), which is based on HTML5 History Mode. It gives the best experience and allows search engines to better crawl STAC Browser so that it can be found in search engines.

History mode requires that you enable custom URL rewriting rules on your host/server, otherwise people can not reload pages or share URLs without getting a "page not found" error (404). The following link explains the details and provides examples for various common server software: https://v3.router.vuejs.org/guide/essentials/history-mode.html#example-server-configurations

Please note that you can't host any other files in the folder that STAC Browser is in as the URL rewriting will redirect all requests to these (sub)-folders and included files to STAC Browser. This also excludes hosting your STAC catalog in the STAC Browser (sub-)folders.

hash

If your host/server doesn't support URL rewriting or you experience other related problems, you can enable hash mode. Either set this option to hash in the config file or append --historyMode=hash when running or building. Known hosts that require hash mode are Amazon S3 and GitHub Pages.

pathPrefix

build-only option

If you don't deploy the STAC Browser instance at the root path of your (sub) domain, then you need to set the path prefix when building (or running) STAC Browser.

npm run build -- --pathPrefix="/browser/"

This will build STAC Browser in a way that it can be hosted at https://example.com/browser for example. Using this parameter for the dev server will make STAC Browser available at http://localhost:8080/browser.

stacProxyUrl

experimental

Setting the stacProxyUrl allows users to modify the URLs contained in the catalog to point to another location. For instance, if you are serving a catalog on the local file system at /home/user/catalog.json, but want to serve the data out from a server located at http://localhost:8888/, you can use:

npm start -- --open --stacProxyUrl=/home/user http://localhost:8888

Notice the format of the value:

• In CLI it is the original location and the proxy location separated by a space character, i.e. {original} {proxy} as in the example above.
• In the config file it is a two-element array with the original location as first element and the proxy location as the second element. Set the option to null to disable it (default).

In this example, any href contained in the STAC (including link or asset hrefs) will replace any occurrence of /home/user/ with http://localhost:8888.

This can also be helpful when proxying a STAC that does not have cors enabled; by using stacProxyUrl you can proxy the original STAC server with one that enables cors and be able to browse that catalog.

buildTileUrlTemplate

The option controls the tile layer that is used to render imagery such as (cloud-optimized) GeoTiffs.

See the documentation for the corresponding stac-layer option for details.

Please note that this option can only be provided through a config file and is not available via CLI/ENV.

If the option useTileLayerAsFallback is set to true, the tile server is only used as a fallback.

Note: This option replaces the v2 options TILE_SOURCE_TEMPLATE and TILE_PROXY_URL. The v3-dev option tileSourceTemplate has been removed in favor of this option.

useTileLayerAsFallback

Depending on this option, either client-side or server-side rendering of imagery such as (cloud-optimized) GeoTiffs can be enabled/disabled.

If buildTileUrlTemplate is given server-side rendering of GeoTiffs is enabled. If server-side rendering should only be used as a fallback for client-side rendering, enable the boolean useTileLayerAsFallback option.

To clarify the behavior, please have a look at the following table:

useTileLayerAsFallback	buildTileUrlTemplate	primary imagery renderer	fallback imagery renderer
true	function	client-side	tile-server
false	function	tile-server	none
true	null	client-side	none
false	null	none	none

By default, client-side rendering is enabled. A server-side fallback is provided via the tiles.rdnt.io project, which serves publicly accessible GeoTiffs as tile layers.

displayGeoTiffByDefault

If set to true, the map also shows non-cloud-optimized GeoTiff files by default. Otherwise (false, default), it only shows COGs and you can only enforce showing GeoTiffs to be loaded with the "Show on map" button but they are never loaded automatically. Loading non-cloud-optimized GeoTiffs only works reliably for smaller files (< 1MB). It may also work for larger files, but it is depending a lot on the underlying client hardware and software.

redirectLegacyUrls

experimental

If you are updating from on old version of STAC Browser, you can set this option to true to redirect users from the old "unreadable" URLs to the new human-readable URLs.

itemsPerPage

The number of items requested and shown per page by default. Only applies to APIs that support the limit query parameter.

maxPreviewsOnMap

The maximum number of previews (thumbnails or overviews) of items that will be shown on the map when on Catalog or Collection pages.

cardViewMode

The default view mode for lists of catalogs/collections. Either "list" or "cards" (default).

cardViewSort

The default sorting for lists of catalogs/collections or items. One of:

• "asc": ascending sort (default)
• "desc": descending sort
• null: sorted as in the source files

showKeywordsInItemCards

Enables keywords in the lists of items if set to true. Defaults to false.

showKeywordsInCatalogCards

Enables keywords in the lists of catalogs/collections if set to true. Defaults to false.

showThumbnailsAsAssets

Defines whether thumbnails are shown in the lists of assets (true, default) or not.

defaultThumbnailSize

The default size [Height, Width] for thumbnails which is reserved in card and list views so that the items don't jump when loading the images. This can be overridden per thumbnail by declaring the proj:shape on the asset or link.

crossOriginMedia

The value for the crossorigin attribute that is sent when loading images through the browser. Default to null. If you encounter issues with loading images, you may want to try setting this to anonymous.

requestHeaders

experimental

The headers given in this option are added to all requests that are sent to the selected STAC catalog or API. This is affected by allowedDomains.

Example: {'Authorization': 'Bearer 134567984623223'} adds a Bearer token to the HTTP headers.

Please note that this option can only be provided through a config file and is not available via CLI/ENV.

requestQueryParameters

experimental

The query parameters given in this option are added to all requests that are sent to the selected STAC catalog or API. This is affected by allowedDomains.

Example: {'f': 'json'} adds a f query parameter to the HTTP URL, e.g. https://example.com?f=json.

Please note that this option can only be provided through a config file and is not available via CLI/ENV.

authConfig

experimental

This allows to enable some authentication methods. Currently the supported methods are:

• API Keys (type: apiKey) via query parameter or HTTP Header
• HTTP Basic (type: http, scheme: basic)
• OpenID Connect (type: openIdConnect)

Authentication is disabled by default (null).

The options you can set in the authConfig object are defined in the Authentication Scheme Object of the STAC Authentication Extension (limited by the supported methods listed above).

Note: Before STAC Browser 3.2.0 a different type of object was supported. The old way is deprecated, but will be converted to the new object internally. Please migrate to the new configuration options now.

In addition the following properties are supported:

• formatter (function|string|null): You can optionally specify a formatter for the query string value or HTTP header value respectively. If the string "Bearer" is provided formats as a Bearer token according to RFC 6750. If not given, the token is sent as provided by the user.
• description (string|null): Optionally a description that is shown to the user. This should explain how the credentials can be obtained for example. CommonMark is allowed. Note: You can leave the description empty in the config file and instead provide a localized string with the key authConfig -> description in the file for custom phrases (src/locales/custom.js).

Authentication is generally affected by the allowedDomains option.

The authConfig option can only be provided through a config file and is not available via CLI/ENV.

API Keys

API keys can be configured to be sent via HTTP header or query parameter:

• For query parameters you need to set in: query with a respective name for the query parameter
• For HTTP headers you need to set in: header with a respective name for the header field

Example 1: HTTP Request Header Value

{
  type: 'apiKey',
  in: 'header',
  name: 'Authorization',
  formatter: token => `Bearer ${token}`, // This is an example, there's also the simpler variant to just provide the string 'Bearer' in this case
  description: `Please retrieve the token from our [API console](https://example.com/api-console).\n\nFor further questions contact <mailto:[email protected]>.`
}

For a given token 123 this results in the following additional HTTP Header: Authorization: Bearer 123

Example 2: Query Parameter Value

{
  type: 'apiKey',
  in: 'query',
  name: 'API_KEY'
}

For a given token 123 this results in the following query parameter: https://example.com/stac/catalog.json?API_KEY=123

HTTP Basic

HTTP Basic is supported according to RFC 7617.

Example:

{
  type: 'http',
  scheme: 'basic'
}

OpenID Connect

IMPORTANT: OpenID Connect is only supported if historyMode is set to history!

For OpenID Connect some additional options must be provided, which currently follow the oidc-client-ts Configuration options. These options (except for issuer) must be provided in the property oidcConfig. The client_id option defaults to stac-browser. The redirect URL for the OIDC client must be set as follows:

Example

{
  type: 'openIdConnect',
  openIdConnectUrl: 'https://stac.example/.well-known/openid-configuration',
  oidcConfig: {
    client_id: 'abc123'
  }
}

For a given token 123 this results in the following additional HTTP Header: Authorization: Bearer 123

You can change the default behaviour to send it as a Bearer token by providing in, name and format.

preprocessSTAC

experimental

This allows to preprocess the STAC Items, Catalogs and Collections that are requested from the servers using a function. The function receives two parameters:

• stac (object of type STAC)
• state (the vuex state)

Please note that this option can only be provided through a config file and is not available via CLI/ENV.

Example: Update root catalog

Some root catalogs in implementations don't have very useful titles, descriptions and are not a nice "intro" for new users. Thus, it may make sense to change the root catalog to provide more useful information. Of course, ideally you'd want to update the root catalog itself, but until then you can use this.

preprocessSTAC: (stac, state) => {
    if (stac.getBrowserPath() === '/') {
        stac.title = state.catalogTitle;
        stac.description = 'This is a **much** more useful description for this catalog!';
    }
    return stac;
}