---
title: 'Trigger: Query pipeline feature'
slug: '1458'
canonical_url: https://docs.coveo.com/en/1458/
collection: tune-relevance
source_format: adoc
---
# Trigger: Query pipeline feature
A [query pipeline statement](https://docs.coveo.com/en/236/) expressing the `trigger` [query pipeline feature](https://docs.coveo.com/en/234/) defines an action to execute in the [search interface](https://docs.coveo.com/en/2741/) from which a [query](https://docs.coveo.com/en/231/) originates.

> **Important**
>
> If a statement expressing the `trigger` feature isn't associated with a [query pipeline condition](https://docs.coveo.com/en/2793/), it's ignored.

The following `trigger` actions are available:

* `execute` executes a custom JavaScript function call.
* `notify` displays a message to the end [user](https://docs.coveo.com/en/250/).
* `query` performs a new query.
* `redirect` redirects the web browser to a specific URL.

When a statement expressing the `trigger` feature is applied, an object representing the action to perform is generated inside the `triggers` property of the query response.
The search interface from which the query originates is then responsible for translating this object into an action (for example, executing a corresponding JavaScript function call, notifying the end user with a corresponding message, etc.).

> **Notes**
>
> * In the [Coveo Administration Console](https://docs.coveo.com/en/183/), you can manage statements expressing the `trigger` feature [from the **Triggers** subtab](https://docs.coveo.com/en/3413#access-the-triggers-subtab).
> 
> * For usage in Headless/Atomic interfaces, see [Manage trigger rules](https://docs.coveo.com/en/3413/).
> 
> * In a full [Coveo JavaScript Search Framework](https://docs.coveo.com/en/187/) interface, you use the `Triggers` component to automatically handle trigger actions.
> With version [2.8521](https://docs.coveo.com/en/m54e5269#march-2020-release-v28521), standalone search boxes automatically handle `redirect` triggers without the need for a `Triggers` component.

The following diagram shows the process of a query being sent to the Search API and the order of execution of query pipeline features.


![Coveo | diagram showing order of execution](https://docs.coveo.com/en/assets/images/coveo-platform/trigger-statements-diagram.svg)

## Syntax

Use the following [query pipeline language (QPL)](https://docs.coveo.com/en/235/) syntax to define a statement expressing the `trigger` feature:

```text
execute <function> | notify <message> | query <expression> | redirect <url>
```

### `<function>`

A string that contains the JavaScript function call to execute (for example, `myFunction()`).
Boolean, integer, and quoted string function arguments are allowed.

> **Note**
>
> When specifying a function containing arguments (for example, `myFunction(true, 123, "abc")`), the arguments aren't executed in the function as is.
> The argument values are rather returned in an object as follows:
> 
> ```javascript
{
  element: div.CoveoTriggers,
  param1: true,
  param2: 123,
  param3: "abc"
}
```
> 
> Therefore, the corresponding function must be implemented accordingly on client-side.
> For example, if the trigger expression is `execute myFunction(true,123,"abc")`, the corresponding function could be configured as follows:
> 
> ```javascript
function myFunction(paramValues) {
    /*
    `paramValues` appear in an object:
      {
         element: div.CoveoTriggers,
         param1: true,
         param2: 123,
         param3: "abc"
      }
    */
    alert("Hi, This is your answer:  " + paramValues.param3); // paramValues.param3 is "abc"
};
```

### `<message>`

A quoted string that contains a message to display to the end user (for example, `"Hello world!"`).

### `<expression>`

A query expression to perform against the [index](https://docs.coveo.com/en/204/) (for example, `coveo OR "machine learning"`).

### `<url>`

A quoted string that contains a URL to which the browser is redirected (for example, `+"http://www.example.com"+`).

## Example

You create a global condition with the following QPL definition:

```text
when $query contains "trigger statement"
```

In an empty [query pipeline](https://docs.coveo.com/en/180/) named `Testing Triggers`, you create three distinct statements, each expressing the `trigger` feature, with the following QPL definitions:

* **Statement 1:**

```text
execute showAnimation("triggerStatement", 100, true)
```

* **Statement 2:**

```text
notify "Here is some information about the `trigger` query pipeline feature!"
```

* **Statement 3:**

```text
query `@title=="Trigger: Query pipeline feature"`
```

You associate each of these statements with the global condition you created.

A user performs a query against your index with the following payload:

```json
{
  "pipeline": "Testing Triggers",
  "q": "how do trigger statements work"
}
```

This query goes through the `Testing Triggers` query pipeline and satisfies the condition of each statement in that pipeline, so all of the statements are applied.
As a result, the `triggers` property of the query response is populated as follows:

```json
[
  {
    "type": "execute",
    "content": {
      "name": "showAnimation",
      "params": ["triggerStatement", 100, true]
    }
  },
  {
    "type": "notify",
    "content": "Here is some information about the `trigger` query pipeline feature!"
  },
  {
    "type": "query",
    "content": "@title==\"Trigger - Query pipeline feature\""
  }
]
```

The search interface from which the query originated ensures that the corresponding actions are executed.