Working with placeholders in a JSS React sample app

The most common way to add a placeholder to a component is to use the Placeholder component.

import { Placeholder } from '@sitecore-jss/sitecore-jss-react';

const App = ({ rendering }) => (
  <div>
    <h1>My App</h1>
    <Placeholder name="jss-main" rendering={rendering} />
  </div>
);

For the Placeholder component:

The higher-order component (HOC) pattern lets you get an array of the components in a placeholder injected as a property to the component that exposes the placeholder.

import { withPlaceholder } from '@sitecore-jss/sitecore-jss-react';

const Tabs = ({ tabs }) => {
  return (
    <div>
      {tabs}
    </div>
  );
};

export default withPlaceholder('tabs')(Tabs);

When you emit the component array, the application renders the components where you emit them. The main advantage of this technique is that there is no wrapper component. If you use the Placeholder component, all child components render underneath it in the component tree. If you emit the placeholder with this technique, the placeholder has no wrapping component and renders inline. This approach is handy when you are using libraries based on a specific component hierarchy, as shown in the following example of react-fullpage:

<SectionsContainer>
  <Section color="#69D2E7">Page 1</Section>
  <Section color="#A7DBD8">Page 2</Section>
  <Section color="#E0E4CC">Page 3</Section>
</SectionsContainer>

In the preceding sample, it is expected that the component hierarchy is SectionsContainer->Section. If you want, you can add the Section components using a placeholder so that Sitecore could define them. If you do this using the Placeholder component, the hierarchy instead looks like SectionsContainer -> Placeholder -> YourComponent -> Section:

<SectionsContainer>
  <Placeholder name="jss-sections" rendering={rendering} />
</SectionsContainer>

With the HOC-based placeholder, you can solve this with either inline components or component transformation:

import { withPlaceholder } from '@sitecore-jss/sitecore-jss-react';

const ContainerComponent = ({ sectionsPlaceholder }) => {
  return <SectionsContainer>{sectionsPlaceholder}</SectionsContainer>;
};

// you can also alias the property for the placeholder when using the HOC - or pass an array of placeholders
export const ContainerSitecoreComponent = withPlaceholder({ placeholder: 'sections', prop: 'sectionsPlaceholder' })(ContainerComponent);

// the <Section> is in the child Sitecore component added to the placeholder
export const ChildSitecoreComponent = (props) => (
  <Section>
    <h1>Your JSS or other React components here</h1>
  </Section>
);

const ContainerComponent = ({ sectionsPlaceholder }) => {
  return (
    <SectionsContainer>
      {sectionsPlaceholder.map((component, index) => {
        // this if is important, as it prevents breakage when using Sitecore Experience Editor
        if (component.props && component.props.type === 'text/sitecore') return component;

        // wraps _all_ child components in a <Section> component
        return <Section key={index}>{component}</Section>;
      })}
    </SectionsContainer>
  );
};

export const ContainerSitecoreComponent = withPlaceholder({ placeholder: 'sections', prop: 'sectionsPlaceholder' })(ContainerComponent);

JSS supports the render props pattern if you prefer it to higher-order components. Using the render property of the <Placeholder> component, you can take over the rendering of placeholder contents the same way as with the higher-order component and use dynamic properties.

The following example illustrates how to get the components array and render it using render properties.

import { Placeholder } from '@sitecore-jss/sitecore-jss-react';

const App = ({ rendering }) => (
  <div>
    <h1>My App</h1>
    <Placeholder name="jss-main" rendering={rendering} render={(components, placeholderData, props) => <div>{components}</div>} />
  </div>
);

You can use two optional arguments to the render function of the placeholder:

If you want to access the data of a placeholder instead of its components, that is also possible. A good use case for this technique is components such as tabs that might need to render pieces in two places (the tab title and the tab contents). Because the placeholder hierarchy is a big JavaScript object, you can traverse it yourself using props.rendering to discover child component data and fields:

const Tabs = ({ rendering, tabs }) => (
<Tab.Container>
  <div class="tabsHeading">
    {(rendering.placeholders.tabs || [])
      .filter((tab) => tab && tab.fields && tab.fields.title)
      .map((tab, index) => (
        <Tab.Heading key={index}>
          <Text field={tab.fields.title} />
        </Tab.Heading>
      ))}
  </div>

  <div class="tabContents">
    {tabs}
  </div>
</Tab.Container>
);

export default withPlaceholder('tabs')(Tabs);

Technically it is possible to take over and render a placeholder completely custom using this technique without using any placeholder component or HOC. We do not usually recommend this.

The Placeholder component supports several customizations that can enhance the developer experience. The same customizations are possible on the HOC placeholder by using the propsTransformer option to inject the same props using a function.