WORKFLOW

Create an Index for a Cloud Directory

Create an index file to list the contents of the cloud directory.

Using an Index Notebook...

Create the directory

Use CreateDirectory to create a new directory. Provide a CloudObject with a name to create the directory in the Wolfram Cloud:

This directory does not contain an index:

  • If you visit a cloud object directory without an index file, it will show a page indicating it is an empty directory, instead of giving the 500 Internal Server Error page.

Add files to the directory

Create an Association of file names to images:

Use CloudExport to export images to the Wolfram Cloud:

Create the index notebook API

Use Information to get the file names of the directory:

Use APIFunction to create an API that identifies all the files in the directory, turns them into hyperlinks, and puts the output in an index notebook:

  • Use SetDelayed instead of Set to delay the execution of names until the API is accessed.

Deploy to the Wolfram Cloud

Use CloudDeploy to deploy the API to the cloud:

The directory now shows an index notebook:

  • “index.nb” is a magic name and must be used.

Using an HTML Index...

Create the directory

Use CreateDirectory to create a new directory. Provide a CloudObject with a name to create the directory in the Wolfram Cloud:

This directory does not contain an index:

  • If you visit a cloud object directory without an index file, it will show a page indicating it is an empty directory, instead of giving the 500 Internal Server Error page.

Add files to the directory

Create an Association of file names to images:

Use CloudExport to export images to the Wolfram Cloud:

Create the index notebook API

Use Information to get the file names of the directory:

Use APIFunction to create an API that identifies all the files in the directory, opens them to create an image collage, and puts the output in HTML:

  • Use SetDelayed instead of Set to delay the execution of names until the API is accessed.

Deploy to the Wolfram Cloud

Use CloudDeploy to deploy the API to the cloud:

The directory now shows an index file:

  • “index.html” is a magic name and must be used.

Notes

If both an index.html and index.nb object are present in the CloudObject directory, the index.html will be used.
The CloudObject can be any type (including an APIFunction, Delayed or FormPage), but the CloudObject must have the name index.html or index.nb.
You need to assign appropriate permissions to the index objects. Examples include read permissions for static content and execute permissions for server-side Wolfram Language content.