# Migrating data for Arc XP Blocks

Source: https://dev.arcxp.com/themes/getting-started/migrating-data-for-arc-blocks/

The Arc XP Blocks used in Theme websites are set up to use [Arc XP Native Specification (ANS)](https://github.com/washingtonpost/ans-schema) schema. They are optimized to work with the data as output by Arc XP applications such as Composer, Photo Center, and Author Service. For more information, see [Understanding Arc XP Native Specification](https://dev.arcxp.com/concepts/content-model-ans/understanding-arc-native-specification-ans/).

Below is a list of ANS fields used in each Arc XP block that you must be aware of if you are migrating content into Arc XP and intend to use Arc XP Blocks.

## NAVIGATION BLOCKS

### alert-bar-block

**ANS fields**

- `content_elements[0]` only uses first content element. used to check whether to render headline
- `content_elements[0].websites[arcSite]` Uses `website_url`
- `content_elements[0].headlines.basic`

### footer-block

**ANS Fields**

Available through `useContent`

- `children`
- `children[x].node_type`
- `children[x].url`
- `children[x].display_name`
- `children[x].name`

### header-nav-block

**ANS Fields**

- `children` available via site-service-hierarchy (optional)
- `children[x].node_type`
- `children[x].url`
- `children[x].display_name`
- `children[x].name`

### links-bar-block

**ANS Fields**

- `children` array
- `children[x].node_type` determines what kind of content to render
- `children[x].url`
- `children[x].display_name`
- `children[x].name`

## CONTENT HEADER BLOCKS

### byline-block

**ANS Fields**

- `credits.by`

### date-block

**ANS Fields**

- `display_date` global date fallback string

### headline-block

**ANS Fields**

- `headlines.basic`

### lead-art-block

**ANS Fields**

- `promo_items.lead_art or promo_items.basic` \= lead\_art
- `lead_art.caption`
- `lead_art.subtitle`
- `lead_art.credits`
- `lead_art.content`
- `lead_art.type` determines what kind of content to render with

### overline-block

**ANS Fields**

- `globalContent.label.basic.display`
- `globalContent.label.basic.url`
- `globalContent.label.basic.text`
- `content.websites[arcSite].website_section._id`
- `content.websites[arcSite].website_section.name`

### subheadline-block

**ANS Fields**

- `content.subheadlines.basic`

## CONTENT ITEM BLOCKS

### article-body-block

**ANS fields**

- `content_elements`
- `content_elements[x].type` Check how many paragraphs included
- `content_elements[x].content` Creates article body with included content

### article-tag-block

**ANS Fields**

- `taxonomy.tags[x].slug` Detects for ’#’ as href for fallback
- `taxonomy.tags[x].text` Required to be string

### author-bio-block

**ANS fields**

- `credits.by` via globalContent
- `credits.by[x]`
- `credits.by[x].description` optional
- `credits.by[x].additional_properties.original` optional

### gallery-block

**ANS Fields**

- `globalContent.headlines.basic` (optional)
- `globalContent.content_elements` (see below) for Engine Theme SDK Gallery component

### share-bar-block

**ANS Fields**

- `globalContent.headlines.basic`
- `globalContent.website_url`

### video-player-block

**ANS Fields**

- `embed_html`

## PROMO BLOCKS

### card-list-block

**ANS Fields**

- `content_elements[x].websites[arcSite].website_url`
- `content_elements[0].credits.by` Check for multiple authors in first article
- `content_elements[0].websites[arcSite]` Uses `website_url`
- `content_elements[0].headlines.basic`

### large-promo-block

**ANS Fields**

- `content.headlines.basic`
- `content.description.basic`
- `content.websites[arcSite].website_section`
- `content.promo_items`

### medium-promo-block

**ANS Fields**

- `content.headlines.basic`
- `content.description.basic`
- `content.websites[arcSite].website_section`
- `content.promo_items`

### numbered-list-block

**ANS Fields**

- `content_elements.headlines.basic`
- `content_elements.promo_items`
- `content_elements.websites[arcSite].website_url`

### small-promo-block

**ANS Fields**

- `content.headlines.basic`
- `content.description.basic`
- `content.websites[arcSite].website_section`
- `content.promo_items`

### top-table-list-block

**ANS Fields**

- `promo_items.basic.url`
- `promo_items.basic.type`
- `promo_items.label.basic.display`
- `promo_items.label.basic.url`
- `promo_items.label.basic.text`
- `promo_items.headlines.basic`
- `promo_items.content.description.basic`

## RESULTS PAGE BLOCKS

### full-author-bio-block

**ANS Fields**

- `authors[0]` Only uses first author

### results-list-block

**ANS Fields**

- `content_elements[x].description.basic`
- `content_elements[x].headlines.basic`
- `content_elements[x].display_date`
- `content_elements[x].credits.by`
- `content_elements[x].promo_items`
- `content_elements[x].websites`

### section-title-block

**ANS Fields**

- `content.children[x].id`
- `content.children[x]._id` used as href for link
- `content.children[x].name`

### simple-list-block

**ANS Fields**

- `content_elements[x].description.basic`
- `content_elements[x].headlines.basic`
- `content_elements[x].display_date`
- `content_elements[x].credits.by`
- `content_elements[x].promo_items`
- `content_elements[x].websites`

### tag-title-block

**ANS Fields**

- `content.Payload[0].name`
- `content.Payload[0].description`