# Module: Layout Template

- [Module: Layout Template](#module-layout-template)
  - [Overview](#overview)
  - [Overview Video](#overview-video)


## Overview
`LayoutTemplates` are a new concept in v3 that modes use to control the layout of a route.
A layout template is a React component that is given a set of managers that define apis to access toolbar state, commands, and hotkeys, as well as props defined by the layout template.

For instance the default LayoutTemplate takes in leftPanels, rightPanels and viewports as props, which it uses to build its view.

In addition, `layout template` has complete control over the structure of the application. You could have tools down the left side, or a strict guided workflow with tools set programmatically, the choice is yours for your use case.


```jsx
const getLayoutTemplateModule = (/* ... */) => [
  {
    id: 'exampleLayout',
    name: 'exampleLayout',
    component: ExampleLayoutComponent,
  },
];
```

The `props` that are passed to `layoutTemplate` are managers and service, along with
the defined mode left/right panels, mode's defined viewports and OHIF `ViewportGridComp`.
LayoutTemplate leverages extensionManager to grab typed extension module entries:
`*.getModuleEntry(id)`




A simplified code for `Default extention`'s layout template is:

```jsx
// extensions/default/src/ViewerLayout/index.jsx
import React from 'react'
import { SidePanel } from '@ohif/ui'

function Toolbar({ servicesManager }) {
  const { ToolBarService } = servicesManager.services

  return (
    <>
      // ToolBarService.getButtonSection('primary') to get toolbarButtons
      {toolbarButtons.map((toolDef, index) => {
        const { id, Component, componentProps } = toolDef
        return (
          <Component
            key={id}
            id={id}
            {...componentProps}
            bState={buttonState}
            isActive={isActive}
            onInteraction={(args) => ToolBarService.recordInteraction(args)}
          />
        )
      })}
    </>
  )
}

function ViewerLayout({
  // From Extension Module Params
  extensionManager,
  servicesManager,
  hotkeysManager,
  commandsManager,
  // From Modes
  leftPanels,
  rightPanels,
  viewports,
  ViewportGridComp,
}) {
  const getPanelData = (id) => {
    const entry = extensionManager.getModuleEntry(id)
    const content = entry.component

    return {
      iconName: entry.iconName,
      iconLabel: entry.iconLabel,
      label: entry.label,
      name: entry.name,
      content,
    }
  }

  const getViewportComponentData = (viewportComponent) => {
    const entry = extensionManager.getModuleEntry(viewportComponent.namespace)

    return {
      component: entry.component,
      displaySetsToDisplay: viewportComponent.displaySetsToDisplay,
    }
  }

  const leftPanelComponents = leftPanels.map(getPanelData)
  const rightPanelComponents = rightPanels.map(getPanelData)
  const viewportComponents = viewports.map(getViewportComponentData)

  return (
    <div>
      <Toolbar servicesManager={servicesManager} />

      <div>
        {/* LEFT SIDEPANELS */}
        <SidePanel
          side="left"
          defaultComponentOpen={leftPanelComponents[0].name}
          childComponents={leftPanelComponents}
        />

        {/* TOOLBAR + GRID */}
        <ViewportGridComp
          servicesManager={servicesManager}
          viewportComponents={viewportComponents}
          commandsManager={commandsManager}
        />

        {/* Rigth SIDEPANELS */}
        <SidePanel
          side="right"
          defaultComponentOpen={rightPanelComponents[0].name}
          childComponents={rightPanelComponents}
        />
      </div>
    </div>
  )
}
```

## Overview Video

<div style="padding:56.25% 0 0 0;position:relative;"><iframe src="https://player.vimeo.com/video/545993263?badge=0&amp;autopause=0&amp;player_id=0&amp;app_id=58479" frameborder="0" allow="autoplay; fullscreen; picture-in-picture" allowfullscreen style="position:absolute;top:0;left:0;width:100%;height:100%;" title="Viewer-layout"></iframe></div><script src="https://player.vimeo.com/api/player.js"></script>