Image List

The Alexa image list template (AlexaImageList) displays a scrolling list of images and text. AlexaImageList is a full-screen template that optionally displays a header, footer, and background. You provide a set of image-based items to display in the list and configure the appearance of the list, such as including dividers and whether to number the items. You can also provide the command to run when a user selects an item from the list.

Compatibility

AlexaImageList is designed to work with all standard viewport profiles in the alexa-viewport-profiles package:

• All hub round profiles
• All hub landscape profiles
• All hub portrait profiles
• All mobile profiles
• All TV profiles

If you use AlexaImageList on an unsupported viewport, you might have unexpected results. For details about viewport profiles, see Viewport Profiles.

Import the alexa-layouts package

To use AlexaImageList, import the alexa-layouts package.

The latest version of the alexa-layouts package is 1.7.0. AlexaImageList was introduced in version 1.1.0.

AlexaImageList parameters

All parameters except type are optional.

Provide the list items

The AlexaImageList template expects an array of items in the listItems property. Each item is an object with the same properties as those defined in the AlexaImageListItem responsive component.

The following example illustrates an array of items in a data source called imageListData.

{
  "imageListData": {
    "listItemsToShow": [
      {
        "primaryText": "First list item",
        "secondaryText": "Secondary text",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gruyere.png",
        "imageProgressBarPercentage": 90,
        "imageShowProgressBar": false,
        "ratingSlotMode": "multiple",
        "ratingNumber": 2.87,
        "ratingText": "(206 ratings)"
      },
      {
        "primaryText": "Second list item",
        "secondaryText": "Secondary Text",
        "tertiaryText": "Tertiary text",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gorgonzola.png",
        "providerText": "Provider Text",
        "imageProgressBarPercentage": 50,
        "ratingSlotMode": "multiple",
        "ratingNumber": 4.5,
        "ratingText": "(500 ratings)"
      },
      {
        "primaryText": "No image, use the default",
        "secondaryText": "Secondary text",
        "ratingSlotMode": "multiple",
        "ratingNumber": 2,
        "ratingText": "(50 ratings)"
      },
      {
        "primaryText": "Fourth list item",
        "secondaryText": "No progress bar",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/tl_brie.png",
        "ratingSlotMode": "multiple",
        "ratingNumber": 5,
        "ratingText": "(452 ratings)"
      },
      {
        "primaryText": "Fifth list item",
        "secondaryText": "With background blur",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/MollyforBT7.png",
        "ratingSlotMode": "multiple",
        "ratingNumber": 0,
        "ratingText": "(206 ratings)"
      },
      {
        "primaryText": "Sixth list item (long text that wraps)",
        "secondaryText": "Longer secondary text that truncates",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/sm_blue.png",
        "ratingSlotMode": "multiple",
        "ratingNumber": 0,
        "ratingText": "(206 ratings)"
      }
    ]
  }
}

Then, bind this array to the listItems property with the expression ${imageListData.listItemsToShow}.

{
  "type": "AlexaImageList",
  "listItems": "${imageListData.listItemsToShow}",
  "defaultImageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/BT7_Background.png",
  "imageBlurredBackground": true,
  "primaryAction": {
    "type": "SendEvent",
    "arguments": [
      "ListItemSelected",
      "${ordinal}"
    ]
  }
}

The specific list item parameters available depend on the version of AlexaImageListItem. For example, the properties to display a rating require the 1.2.0 or later version of the alexa-layouts package. For the full set of properties, see AlexaImageListItem.

Set defaults for the list items

The AlexaImageList template includes properties that correspond to properties in AlexaImageListItem. Use these to set default values for those properties.

There are two types of defaults:

• Defaults you can set or override for an individual item – AlexaImageList uses the value provided on the individual item when available, and uses the value provided on AlexaImageList otherwise.

  For example, you might set imageScale to best-fit for the whole list, but then override it to best-fill for one item on the list.

• Defaults that always apply to all the items in the list – AlexaImageList always uses the value provided on AlexaImageList for these properties. Any value in a corresponding property on an individual item is ignored.

  For example, you must set imageAspectRatio on the whole list. You can't have a list in which some items display as squares and some as circles. Any value for imageAspectRatio on a list item is ignored.

The following table lists the properties you use as defaults.

For details about each of these properties, see AlexaImageListItem.

Specify the action for each list item

AlexaImageList is interactive. Users can select items on the list. Set the primaryAction property to the command you want to run when the user selects an item.

When you set primaryAction on the AlexaImageList component, AlexaImageList passes the command to each item on the list.

To override command for an individual list item, set the primaryAction property on the list item itself.

The following example shows how you to use the SendEvent command to send your skill a UserEvent request. This passes the number representing the selected item as part of the SendEvent.arguments array.

{
  "primaryAction": {
    "type": "SendEvent",
    "arguments": [
      "ListItemSelected",
      "${ordinal}"
    ]
  }
}

Use the SpeakList command with AlexaImageList

Use the speechItems parameter on AlexaImageList when you want to use the SpeakList command to read the list of items. Set the speechItems property to an array of items.

The SpeakList command requires a speech property on each list item to speak. The speech property must be set to the output of either the ssmlToSpeech or textToSpeech transformer. Therefore, you need to do the following to use SpeakList with AlexaImageList:

• Use an object type data source for the array of items to speak. Within this data source, configure either the ssmlToSpeech or textToSpeech transformer to process the array of items to speak.
• Bind the speechItems property of the AlexaImageList to list of items to speak.
• Invoke the SpeakList command for the list.

Configure a data source for list speech items

1. Create an object type data source to use with your document.

2. In the data source, add an array of items to speak to a property within the properties object in the data source.

   The following example shows an object data source that contains an array called listItemsToShow. Note that the array of items is within the properties object.

    {
      "imageListData": {
        "type": "object",
        "objectId": "imageListDataId",
        "properties": {
          "listItemsToShow": [
            {
              "primaryText": "First list item",
              "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gruyere.png"
            },
            {
              "primaryText": "Second list item",
              "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gorgonzola.png"
            }
          ]
        }
      }
    }
   

3. Configure the ssmlToSpeech or textToSpeech transformer with the following settings:

   • inputPath – The array of items to speak. The transformer expects the path you provide to be within the properties object, so you don't need to include properties in the path. When the items in your array are objects, specify the specific field within the object that contains the text or SSML.
   • outputName – Set to the string "speech". The AlexaImageList template includes "speech" when handling the list of items, so you must use this exact string.
   • transformer – Either ssmlToSpeech or textToSpeech, depending on the format of the items in the array

   The following example configures the textToSpeech transformer to process the primaryText field for each item in the listItemsToShow array.

    {
      "transformers": [
        {
          "inputPath": "listItemsToShow[*].primaryText",
          "outputName": "speech",
          "transformer": "textToSpeech"
        }
      ]
    }
   

Bind the speechItems property to the list of items to speak

In your APL document, use a data-binding expression to bind the speechItems property of AlexaImageList to your list of items to speak.

Continuing the previous example, the expression is ${imageListData.properties.listItemsToShow}. This example uses the same primaryText both for display and for speech.

{
  "type": "AlexaImageList",
  "listItems": "${imageListData.properties.listItemsToShow}",
  "speechItems": "${imageListData.properties.listItemsToShow}"
}

Run the SpeakList command for the list

Run the SpeakList command when you want Alexa to read the items provided in speechItems. For example, you might run the command from the onMount handler to read the items after the device displays the document.

1. Assign the listId parameter on AlexaImageList to an ID unique to your document. You must provide this ID to run SpeakList.

    {
      "type": "AlexaImageList",
      "listId": "myImageListWithItemsToSpeak",
      "listItems": "${imageListData.properties.listItemsToShow}",
      "speechItems": "${imageListData.properties.listItemsToShow}"
    }
   

2. Set the componentId property for the SpeakList command to the ID you provided for listId.

   The following example invokes the command in the onMount handler. Alexa speaks the items after the device displays the document.

    {
      "onMount": [
        {
          "type": "SpeakList",
          "delay": 5000,
          "componentId": "myImageListWithItemsToSpeak",
          "start": 0,
          "count": "${imageListData.properties.listItemsToShow.length}",
          "minimumDwellTime": 1000,
          "align": "center"
        }
      ]
    }
   

The following examples show the complete document and data source. After the device displays the document, Alexa reads the primary text for each of the six items in the list. The SpeakList command includes the five second delay to allow Alexa to speak the normal speech output for the skill response before reading the list items.

Example document: AlexaImageList and SpeakList  

{
  "type": "APL",
  "version": "2023.2",
  "import": [
    {
      "name": "alexa-layouts",
      "version": "1.7.0"
    }
  ],
  "mainTemplate": {
    "parameters": [
      "imageListData"
    ],
    "item": {
      "type": "AlexaImageList",
      "listId": "myImageListWithItemsToSpeak",
      "listItems": "${imageListData.properties.listItemsToShow}",
      "speechItems": "${imageListData.properties.listItemsToShow}",
      "headerTitle": "${imageListData.headerTitle}",
      "defaultImageSource": "${imageListData.defaultImageSource}"
    }
  },
  "onMount": [
    {
      "type": "SpeakList",
      "delay": 5000,
      "componentId": "myImageListWithItemsToSpeak",
      "start": 0,
      "count": "${imageListData.properties.listItemsToShow.length}",
      "minimumDwellTime": 1000,
      "align": "center"
    }
  ]
}

Data source: AlexaImageList and SpeakList  

{
  "imageListData": {
    "type": "object",
    "objectId": "imageListDataId",
    "headerTitle": "AlexaImageList Example with the SpeakList Command",
    "headerAttributionImage": "https://s3.amazonaws.com/ask-skills-assets/apl-layout-assets/attribution_dark_hub_prime.png",
    "defaultImageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/BT7_Background.png",
    "properties": {
      "listItemsToShow": [
        {
          "primaryText": "First list item",
          "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gruyere.png"
        },
        {
          "primaryText": "Second list item",
          "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gorgonzola.png"
        },
        {
          "primaryText": "No image, use the default"
        },
        {
          "primaryText": "Fourth list item",
          "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/tl_brie.png"
        },
        {
          "primaryText": "Fifth list item",
          "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/MollyforBT7.png"
        },
        {
          "primaryText": "Sixth list item (long text that wraps)",
          "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/sm_blue.png"
        }
      ]
    },
    "transformers": [
      {
        "inputPath": "listItemsToShow[*].primaryText",
        "outputName": "speech",
        "transformer": "textToSpeech"
      }
    ]
  }
}

AlexaImageList and dynamicIndexList data sources

The AlexaImageList template uses a Sequence. This means you can use a dynamicIndexList data source. With a dynamicIndexList data source, you can do the following:

• Display large lists progressively as the user scrolls through the content (lazy loading).
• Update the items the data source after it is already displayed, so you can change the values on the screen without sending an entirely new document.

To use a dynamicIndexList data source with AlexaImageList

1. Follow the dynamicIndexList structure shown in dynamicIndexList data source. Don't include any other properties not defined in this structure.
2. Put your list item objects in the items array in the data source.
3. Bind the data source to the listItems property of AlexaImageList. This binding is equivalent to binding the data source to the data property of a Sequence in a custom layout.

The following examples show a document with an AlexaImageList that uses a dynamicIndexList data source.

Example document: AlexaImageList bound to dynamicIndexList  

{
  "type": "APL",
  "version": "2023.2",
  "theme": "dark",
  "import": [
    {
      "name": "alexa-layouts",
      "version": "1.7.0"
    }
  ],
  "mainTemplate": {
    "parameters": [
      "imageListData",
      "staticData"
    ],
    "items": [
      {
        "type": "AlexaImageList",
        "headerTitle": "${staticData.headerTitle}",
        "headerSubtitle": "${staticData.headerSubtitle}",
        "headerAttributionImage": "${staticData.headerAttributionImage}",
        "backgroundImageSource": "${staticData.backgroundImageSource}",
        "hintText": "${staticData.hintText}",
        "defaultImageSource": "${staticData.defaultImageSource}",
        "listItems": "${imageListData}",
        "imageBlurredBackground": true,
        "primaryAction": {
          "type": "SendEvent",
          "arguments": [
            "ListItemSelected",
            "${ordinal}"
          ]
        }
      }
    ]
  }
}

Data source: AlexaImageList bound to dynamicIndexList  

{
  "imageListData": {
    "type": "dynamicIndexList",
    "listId": "datasourceForImageList",
    "startIndex": 0,
    "minimumInclusiveIndex": 0,
    "maximumExclusiveIndex": 100,
    "items": [
      {
        "primaryText": "First list item",
        "secondaryText": "Secondary text",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gruyere.png",
        "imageProgressBarPercentage": 90,
        "imageShowProgressBar": false
      },
      {
        "primaryText": "Second list item",
        "secondaryText": "Secondary Text",
        "tertiaryText": "Tertiary text",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/md_gorgonzola.png",
        "providerText": "Provider Text",
        "imageProgressBarPercentage": 50
      },
      {
        "primaryText": "No image, use the default",
        "secondaryText": "Secondary text"
      },
      {
        "primaryText": "Fourth list item",
        "secondaryText": "No progress bar",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/tl_brie.png"
      },
      {
        "primaryText": "Fifth list item",
        "secondaryText": "With background blur",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/MollyforBT7.png"
      },
      {
        "primaryText": "Sixth list item (long text that wraps)",
        "secondaryText": "Longer secondary text that truncates",
        "imageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/sm_blue.png"
      }
    ]
  },
  "staticData": {
    "headerTitle": "Header title for a dynamic list",
    "headerSubtitle": "These static text items are in a different data source",
    "headerAttributionImage": "https://s3.amazonaws.com/ask-skills-assets/apl-layout-assets/attribution_dark_hub_prime.png",
    "backgroundImageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/BT6_Background.png",
    "defaultImageSource": "https://d2o906d8ln7ui1.cloudfront.net/images/BT7_Background.png",
    "hintText": "Footer text"
  }
}

For details about defining a dynamicIndexList data source, see dynamicIndexList data source.

For details about the directives and requests you use to manage the data source, see Alexa.Presentation.APL Interface Reference.

AlexaImageList example

In this example, selecting a list item sends a UserEvent request with "ListItemSelected" and the number of the list item in the arguments array. To test this event, copy the example to your skill.

Related topics

• Alexa Design System Overview
• Responsive Components and Templates
• Alexa Design Guide: Responsive Templates

Last updated: Jun 30, 2023