Example STAC Item with Assets

Oct 13, 2025 by wbrum.org 135 views

Introduction

The [STAC Item] is a crucial component of the Spatial Data on the Web (SDW) ecosystem, providing a standardized way to describe and access geospatial data. As part of this ecosystem, it is essential to have a seamless way to access and utilize the assets associated with a STAC Item. In this article, we will explore how to provide links to assets for download/reference, making it easier for users to access and utilize the data.

Understanding STAC Items

A STAC Item is a JSON object that describes a single geospatial data asset. It contains metadata about the asset, such as its ID, title, description, and links to the asset itself. The STAC Item is the core component of the SDW ecosystem, and it plays a vital role in enabling the discovery, access, and utilization of geospatial data.

Providing Links to Assets

To provide links to assets for download/reference, we need to modify the STAC Item to include links to the assets. This can be done by adding a new property to the STAC Item, such as assets, which contains an array of links to the assets.

Example STAC Item with Assets

{
  "id": "stac-item-1",
  "title": "Example STAC Item",
  "description": "This is an example STAC Item.",
  "assets": [
    {
      "href": "https://example.com/asset1.tif",
      "type": "image/tiff",
      "title": "Asset 1"
    },
    {
      "href": "https://example.com/asset2.tif",
      "type": "image/tiff",
      "title": "Asset 2"
    }
  ]
}

In this example, the STAC Item has two assets, each with a link to the asset, a type, and a title.

Displaying Assets

To display the assets, we can create a user interface that lists the assets and provides links to download and copy the asset URL.

Example User Interface

<h1>Assets for STAC Item</h1>

<ul>
  {% for asset in stac_item.assets %}
  <li>
    <strong>{{ asset.title }}</strong>
    (<a href="{{ asset.href }}">Download</a>)
    (<a href="{{ asset.href }}" onclick="copyToClipboard(this)">Copy URL</a>)
  </li>
  {% endfor %}
</ul>

In this example, the user interface lists the assets and provides links to download and copy the asset URL.

Implementing Copy to Clipboard Functionality

To implement the copy to clipboard functionality, we can use the following JavaScript code:

function copyToClipboard(element) {
  var text = element.getAttribute('href');
  var textarea = document.createElement('textarea');
  textarea.value = text;
  document.body.appendChild(textarea);
  textarea.select();
  document.execCommand('copy');
  document.body.removeChild(textarea);
}

This code creates a temporary textarea element, sets its value to the asset URL, selects the text, and executes the copy command. Finally, it removes the textarea element.

Conclusion

In this article, we explored how to provide links to assets for download/reference in a STAC Item. We modified the STAC Item to include links to the assets and created a user interface that lists the assets and provides links to download and copy the asset URL. We also implemented the copy to clipboard functionality using JavaScript. By following these steps, we can make it easier for users to access and utilize the data associated with a STAC Item.

Future Work

In the future, we can improve the user interface by adding features such as filtering, sorting, and pagination. We can also explore other ways to provide links to assets, such as using a separate endpoint or a different data format.

References

STAC Item Specification
Spatial Data on the Web (SDW) Ecosystem
[STAC Item] - Links to Assets for Download/Reference: Q&A ===========================================================

Introduction

In our previous article, we explored how to provide links to assets for download/reference in a STAC Item. We modified the STAC Item to include links to the assets and created a user interface that lists the assets and provides links to download and copy the asset URL. In this article, we will answer some frequently asked questions about providing links to assets for download/reference in a STAC Item.

Q: What is a STAC Item?

A: A STAC Item is a JSON object that describes a single geospatial data asset. It contains metadata about the asset, such as its ID, title, description, and links to the asset itself.

Q: Why do I need to provide links to assets for download/reference?

A: Providing links to assets for download/reference makes it easier for users to access and utilize the data associated with a STAC Item. It allows users to download the assets directly from the STAC Item, without having to navigate to a separate endpoint or data repository.

Q: How do I modify the STAC Item to include links to assets?

A: To modify the STAC Item to include links to assets, you need to add a new property to the STAC Item, such as assets, which contains an array of links to the assets.

Q: What is the format of the asset links?

A: The asset links are in the format of a JSON object, which contains the following properties:

href: the URL of the asset
type: the MIME type of the asset
title: the title of the asset

Q: How do I display the assets in a user interface?

A: To display the assets in a user interface, you can create a list of the assets and provide links to download and copy the asset URL. You can use HTML and JavaScript to create the user interface.

Q: How do I implement the copy to clipboard functionality?

A: To implement the copy to clipboard functionality, you can use the following JavaScript code:

function copyToClipboard(element) {
  var text = element.getAttribute('href');
  var textarea = document.createElement('textarea');
  textarea.value = text;
  document.body.appendChild(textarea);
  textarea.select();
  document.execCommand('copy');
  document.body.removeChild(textarea);
}

This code creates a temporary textarea element, sets its value to the asset URL, selects the text, and executes the copy command. Finally, it removes the textarea element.

Q: Can I use a separate endpoint or data repository for the assets?

A: Yes, you can use a separate endpoint or data repository for the assets. However, this may require additional configuration and setup.

Q: Are there any security considerations when providing links to assets for download/reference?

A: Yes, there are security considerations when providing links to assets for download/reference. You should ensure that the asset links are secure and that the assets are not accessible to unauthorized users.

Q: Can I use this approach for other types of data, not just geospatial data?

A: Yes, you can use this approach for other types of data, not just geospatial data. However, you may need to modify the STAC Item and the user interface to accommodate the specific requirements of the data.

Conclusion

In this article, we answered some frequently asked questions about providing links to assets for download/reference in a STAC Item. We hope that this article has provided you with a better understanding of how to provide links to assets for download/reference in a STAC Item. If you have any further questions, please don't hesitate to contact us.