# drule.exists

### Description

`boolean drule.exists(object filter)`

This method checks if at least one discrovery rule that matches the
given filter criteria exists.

::: notewarning
This method is deprecated and will be removed in the
future. Please use [drule.get](get) instead.
:::

### Parameters

`(object)` Criteria to search by.

The following parameters are supported as search criteria.

|Parameter|Type|Description|
|---------|----|-----------|
|druleids|string/array|IDs of discovery rules.|
|name|string/array|Names of discovery rules.|

### Return values

`(boolean)` Returns `true` if at least one discrovery rule that matches
the given filter criteria exists.

### Examples

#### Check a discovery rule by name

Check if a discovery rule called "Local network" exists.

Request:

``` {.java}
{
    "jsonrpc": "2.0",
    "method": "drule.exists",
    "params": {
        "name": "Local network"
    },
    "auth": "3a57200802b24cda67c4e4010b50c065",
    "id": 1
}
```

Response:

``` {.java}
{
    "jsonrpc": "2.0",
    "result": true,
    "id": 1
}
```

### See also

-   [drule.isreadable](isreadable)
-   [drule.iswritable](iswritable)

### Source

CDRule::exists() in
*frontends/php/include/classes/api/services/CDRule.php*.