# scheduleCommand Method This is the single most powerful API call, and it exposes a rich suite of functions for extensive control. ```javascript // callback version (first three arguments are required) ServiceHandler.scheduler.scheduleCommand(command, parameters, variables, (res) => { let data; try { data = JSON.parse(res); } catch (e) { data = { result: res }; } console.log(data); }); // promise version (results will be parsed for you) const data = await ServiceHandler.scheduler.scheduleCommand(command, parameters, variables); console.log(data); ``` * `command`: String containing the command; see below for options. * `parameters`: JavaScript object of keys and values determined by the command. * `variables`: JavaScript object of variable names and values. * `callback`: Function to be called with a **JSON-formatted string** of the command results. Available commands include but are not limited to these: | command | what it does | | ---------------------- | --------------------------------------------------------------------------------------------------- | | `schedule` | Internal version of the `scheduleAction` command. | | `macro` | High level title playback control. | | `setTitleInput` | Assign an input to the title. | | `removeTitleInput` | Remove an input from a title. | | `setTitlePosition` | Reposition a title in the list. | | `loadTitle` | Load a title from file, and optionally give it a new name, position, and id. | | `saveTitle` | Save the selected title to file. | | `newTitle` | Create a new title. | | `readTitle` | Get detailed information on a title graphic and its variables. | | `setDynamic` | Specify whether a variable is allowed to change in a title by setting dynamic to 1 or 0 | | `downloadImage` | Download image from a url or parse from a `data:` string, save it to temp file, and return the path | | `getPlayStatus` | Get the playback status of the specific title and variables. | | `getRenderStatus` | Get the render status of a title. | | `getTitlesPlayStatus` | Returns a list of all titles and their input and play status. | | `getInputsPlayStatus` | Returns a list of all inputs and play status on the requested channel. | | `getAllVideoIns` | Returns a list of all video devices available for input | | `getAllAudioIns` | Returns a list of all audio devices available for input | | `isTitleConnected` | Returns true if at least one title in the provided channel is connected to one of a list of inputs. | | `getTitlesConnected` | Returns a list of all titles that are connected to the specified input (or all if input is empty). | | `getTitleControlInfo` | Get extensive information for all titles, just one title, or titles connected to the input. | | `getTitleConnnectInfo` | Get all information pertaining to the connection between inputs and titles. | | `getCachePath` | Gets the current location for the specified title’s cache | | `setCachePath` | Sets a unique location to build the cache for the requested title | | `subscribe` | Subscribe for notifications when titles change play state or their data is updated. | | `unSubscribe` | Unsubscribe for notifications when titles change play state or their data is updated. | | `getSnapShot` | Request a rendering of a title with specific variable settings - can be used to preview. | | `getTitleIcon` | Request a rendering of a title, but only if it has changed since last time. | | `openFileDialog` | Open a file browser to select a file and return its full path. | | `getFileContent` | Read a file (or url) and return its data - useful for files that need to be polled for changes. | | `fetchUrl` | Perform an arbitrary web request similar to JavaScript's `fetch` command | | `encodeImage` | Encodes an image from a file to a dataUrl for easy display in a web UI. | | `assignVariable` | Assign an input variable to a graphic variable. | | `popupAssignVariable` | Open a popup menu to connect the variable to a field in the title. | | `openDesigner` | Open the title designer with the requested title. | | `closeDesigner` | Close the title designer. | | `openUrl` | Open URL in the default system browser. | | `... custom message` | When using the `to` field, your message will be passed to passed to other controllers | > Note: Most commands can be targeted to a specific channel, and the channel should be specified as a number starting at `0`. This is different from the way channels are displayed in the project panel. The tab labeled “Channel 1” is accessed as channel `0`. **Example:** ```javascript // remember, when using the promises version, the response data will be parsed for you const res = await ServiceHandler.scheduler.scheduleCommand( 'downloadImage', { url: 'http://my-images.com/image.jpg' }, {} ); if (res.success) { console.log(`Image downloaded to local cache: ${res.path}`); ServiceHandler.scheduler.scheduleAction(action, inputName, titleId, { 'My Image': res.path }); } ``` There are many more commands than these, including commands to start and join Zoom meetings, commands to retrieve chat messages from a video conference. For a full description of these and all currently available commands, view the [All Commands Reference](https://developers.newbluefx.com/captivate-api/all-commands-reference). Additionally, we provide a [JSON Command Tester](https://developers.newbluefx.com/api-examples/json-command-tester) included in the `API Tour` data controller. You can use that controller to easily test each command and copy/paste code directly from it.