Provide custom data to a placement

Custom data can be added for a specific placement. These parameters apply to a specific placement, such as a placement-level behavior.

Prerequisite

Item	Description
Placement ID	Unique identifier for the placement Follow these steps to obtain the placement ID: On the Dynamic Strategy Rules page, on the Placements tab, click the name of the placement. The placement details page appears. In the row of the placement, copy the ID under the Placement ID column.

Add custom data

There are several approaches to add custom data for a placement: query parameters, HTML attributes, and jwDataStore. The following sections explain how to use each approach.

Query Parameters

Custom data is added through a query string appended to the embed URL.

Topic	Details
Parsing	Only at page load
Supported Data Types	Strings
Requirements	Placement-level custom parameters are prefixed with `custom.{placement-id}`, such as `custom.abcd1234` in the example below. Custom parameters must be lowercase.
Data Override Rules	Overridden by: HTML Attributes jwDataStore
Example	`&custom.abcd1234.view_type=advert`

HTML Attributes

⚠️
This approach is required for the header method.

Custom data is added through data attributes added to a JWP placement <div> element.

Topic	Details
Parsing	Only at page load
Supported Data Types	Strings
Requirements	The JW placement has `data-jw-placement-id` defined. Placement-level custom parameters are prefixed with `data-jw-` Custom parameters must be lowercase.
Data Override Rules	Overrides: Query Parameters Overridden by: jwDataStore
Example	`<div id="jwp-placement-1" data-jw-placement-id="plac1234" data-jw-media_id_1="medi1234" data-jw-playlist_id_1="play1234"> </div>`

jwDataStore

Custom data is added through attributes added at the page level.

Topic	Details
Parsing	At every rule evaluation
Supported Data Types	All types
Requirements	Placement-level custom parameters are stored in `jwDataStore.custom.{placement-id}`, such as `jwDataStore.custom.abcd1234` in the example below. Custom parameters must be lowercase.
Data Override Rules	Overrides: Query Parameters HTML Attributes
Example	`const jwDataStore = window.jwDataStore \|\| { custom: {} }; jwDataStore.custom.abcd1234 = { view_type: "advert" }; window.jwDataStore = jwDataStore;`