Learn how to map React components to Adobe Experience Manager (AEM) components with the AEM SPA Editor JS SDK. Component mapping enables users to make dynamic updates to SPA components within the AEM SPA Editor, similar to traditional AEM authoring.
This chapter takes a deeper-dive into the AEM JSON model API and how the JSON content exposed by an AEM component can be automatically injected into a React component as props.
This chapter inspects how the provided Text
SPA component is mapped to the AEM Text
component. React Core Components like the Image
SPA component is used in the SPA and authored in AEM. Out of the box features of the Layout Container and Template Editor policies are also be used to create a view that is a little more varied in appearance.
Review the required tooling and instructions for setting up a local development environment. This chapter is a continuation of the Integrate the SPA chapter, however to follow along all you need is a SPA-enabled AEM project.
The basic concept is to map a SPA Component to an AEM Component. AEM components, run server-side, export content as part of the JSON model API. The JSON content is consumed by the SPA, running client-side in the browser. A 1:1 mapping between SPA components and an AEM component is created.
High-level overview of mapping an AEM Component to a React Component
The AEM Project Archetype provides a Text
component that is mapped to the AEM Text component. This is an example of a content component, in that it renders content from AEM.
Let’s see how the component works.
Before jumping into the SPA code, it is important to understand the JSON model that AEM provides. Navigate to the Core Component Library and view the page for the Text component. The Core Component Library provides examples of all the AEM Core Components.
Select the JSON tab for one of the examples:
You should see three properties: text
, richText
, and :type
.
:type
is a reserved property that lists the sling:resourceType
(or path) of the AEM Component. The value of :type
is what is used to map the AEM component to the SPA component.
text
and richText
are additional properties that are exposed to the SPA component.
View the JSON output at http://localhost:4502/content/wknd-spa-react/us/en.model.json. You should be able to find an entry similar to:
"text": {
"id": "text-a647cec03a",
"text": "<p>Hello World! Updated content!</p>\r\n",
"richText": true,
":type": "wknd-spa-react/components/text",
"dataLayer": {}
}
In the IDE of your choice open up the AEM Project for the SPA. Expand the ui.frontend
module and open the file Text.js
under ui.frontend/src/components/Text/Text.js
.
The first area we will inspect is the class Text
at ~line 40:
class Text extends Component {
get richTextContent() {
return (<div
id={extractModelId(this.props.cqPath)}
data-rte-editelement
dangerouslySetInnerHTML={{__html: DOMPurify.sanitize(this.props.text)}} />
);
}
get textContent() {
return <div>{this.props.text}</div>;
}
render() {
return this.props.richText ? this.richTextContent : this.textContent;
}
}
Text
is a standard React component. The component uses this.props.richText
to determine whether the content to render is going to be rich text or plain text. The actual “content” used comes from this.props.text
.
To avoid a potential XSS attack, the rich text is escaped via DOMPurify
before using dangerouslySetInnerHTML to render the content. Recall the richText
and text
properties from the JSON model earlier in the exercise.
Next, open ui.frontend/src/components/import-components.js
take a look at the TextEditConfig
at ~line 86:
const TextEditConfig = {
emptyLabel: 'Text',
isEmpty: function(props) {
return !props || !props.text || props.text.trim().length < 1;
}
};
The above code is responsible for determining when to render the placeholder in the AEM author environment. If the isEmpty
method returns true then the placeholder is rendered.
Finally take a look at the MapTo
call at ~line 94:
export default MapTo('wknd-spa-react/components/text')(LazyTextComponent, TextEditConfig);
MapTo
is provided by the AEM SPA Editor JS SDK (@adobe/aem-react-editable-components
). The path wknd-spa-react/components/text
represents the sling:resourceType
of the AEM component. This path gets matched with the :type
exposed by the JSON model observed earlier. MapTo
takes care of parsing the JSON model response and passing the correct values as props
to the SPA component.
You can find the AEM Text
component definition at ui.apps/src/main/content/jcr_root/apps/wknd-spa-react/components/text
.
AEM WCM Components - React Core implementation and AEM WCM Components - Spa editor - React Core implementation. These are a set of re-usable UI components that map to out of the box AEM components. Most projects can re-use these components as a starting point for their own implementation.
In the project code open the file import-components.js
at ui.frontend/src/components
.
This file imports all of the SPA components that map to AEM components. Given the dynamic nature of the SPA Editor implementation, we must explicitly reference any SPA components that are tied to AEM author-able components. This allows an AEM author to choose to use a component wherever they want in the application.
The following import statements include SPA components written in the project:
import './Page/Page';
import './Text/Text';
import './Container/Container';
import './ExperienceFragment/ExperienceFragment';
There are several other imports
from @adobe/aem-core-components-react-spa
and @adobe/aem-core-components-react-base
. These are importing the React Core components and making them available in the current project. These are then mapped to project specific AEM components using the MapTo
, just like with the Text
component example earlier.
Policies are a feature of AEM templates gives developers and power-users granular control over which components are available to be used. The React Core Components are included in the SPA Code but need to be enabled via a policy before they can be used in the application.
From the AEM Start screen navigate to Tools > Templates > WKND SPA React.
Select and open the SPA Page template for editing.
Select the Layout Container and click it’s policy icon to edit the policy:
Under Allowed Components > WKND SPA React - Content > check Image, Teaser, and Title.
Under Default Components > Add mapping and choose the Image - WKND SPA React - Content component:
Enter a mime type of image/*
.
Click Done to save the policy updates.
In the Layout Container click the policy icon for the Text component.
Create a new policy named WKND SPA Text. Under Plugins > Formatting > check all the boxes to enable additional formatting options:
Under Plugins > Paragraph Styles > check the box to Enable paragraph styles:
Click Done to save the policy update.
Navigate to the Homepage http://localhost:4502/editor.html/content/wknd-spa-react/us/en/home.html.
You should now be able to use the additional components Image, Teaser, and Title on the page.
You should also be able to edit the Text
component and add additional paragraph styles in full-screen mode.
You should also be able to drag+drop an image from the Asset finder:
Experiement with the Title and Teaser components.
Add your own images via AEM Assets or install the finished code base for the standard WKND reference site. The WKND reference site includes many images that can be re-used on the WKND SPA. The package can be installed using AEM’s Package Manager.
Support for the Layout Container is automatically provided by the AEM SPA Editor SDK. The Layout Container, as indicated by the name, is a container component. Container components are components that accept JSON structures which represent other components and dynamically instantiate them.
Let’s inspect the Layout Container further.
In a browser navigate to http://localhost:4502/content/wknd-spa-react/us/en.model.json
The Layout Container component has a sling:resourceType
of wcm/foundation/components/responsivegrid
and is recognized by the SPA Editor using the :type
property, just like the Text
and Image
components.
The same capabilities of re-sizing a component using Layout Mode are available with the SPA Editor.
Return to http://localhost:4502/editor.html/content/wknd-spa-react/us/en/home.html. Add additional Image components and try re-sizing them using the Layout option:
Re-open the JSON model http://localhost:4502/content/wknd-spa-react/us/en.model.json and observe the columnClassNames
as part of the JSON:
The class name aem-GridColumn--default--4
indicates the component should be 4 columns wide based on a 12 column grid. More details about the responsive grid can be found here.
Return to the IDE and in the ui.apps
module there is a client-side library defined at ui.apps/src/main/content/jcr_root/apps/wknd-spa-react/clientlibs/clientlib-grid
. Open the file less/grid.less
.
This file determines the breakpoints (default
, tablet
, and phone
) used by the Layout Container. This file is intended to be customized per project specifications. Currently the breakpoints are set to 1200px
and 768px
.
You should be able to use the responsive capabilities and the updated rich text policies of the Text
component to author a view like the following:
Congratulations, you learned how to map SPA components to AEM Components and you used the React Core Components. You also got a chance to explore the responsive capabilities of the Layout Container.
Navigation and Routing - Learn how multiple views in the SPA can be supported by mapping to AEM Pages with the SPA Editor SDK. Dynamic navigation is implemented using React Router and React Core Components.
In many cases, especially at the beginning of an AEM project it is valuable to persist configurations, like templates and related content policies, to source control. This ensures that all developers are working against the same set of content and configurations and can ensure additional consistency between environments. Once a project reaches a certain level of maturity, the practice of managing templates can be turned over to a special group of power users.
The next few steps will take place using the Visual Studio Code IDE and VSCode AEM Sync but could be doing using any tool and any IDE that you have configured to pull or import content from a local instance of AEM.
In the Visual Studio Code IDE, ensure that you have VSCode AEM Sync installed via the Marketplace extension:
Expand the ui.content module in the Project explorer and navigate to /conf/wknd-spa-react/settings/wcm/templates
.
Right+Click the templates
folder and select Import from AEM Server:
Repeat the steps to import content but select the policies folder located at /conf/wknd-spa-react/settings/wcm/templates/policies
.
Inspect the filter.xml
file located at ui.content/src/main/content/META-INF/vault/filter.xml
.
<!--ui.content filter.xml-->
<?xml version="1.0" encoding="UTF-8"?>
<workspaceFilter version="1.0">
<filter root="/conf/wknd-spa-react" mode="merge"/>
<filter root="/content/wknd-spa-react" mode="merge"/>
<filter root="/content/dam/wknd-spa-react" mode="merge"/>
<filter root="/content/experience-fragments/wknd-spa-react" mode="merge"/>
</workspaceFilter>
The filter.xml
file is responsible for identifying the paths of nodes that are installed with the package. Notice the mode="merge"
on each of the filters which indicates that existing content will not be modified, only new content is added. Since content authors may be updating these paths, it is important that a code deployment does not overwrite content. See the FileVault documentation for more details on working with filter elements.
Compare ui.content/src/main/content/META-INF/vault/filter.xml
and ui.apps/src/main/content/META-INF/vault/filter.xml
to understand the different nodes managed by each module.
A SPA Image component has already been provided by the React Core components. However, if you want extra practice, create your own React implementation that maps to the AEM Image component. The Image
component is another example of a content component.
Before jumping into the SPA code, inspect the JSON model provided by AEM.
Navigate to the Image examples in the Core Component library.
Properties of src
, alt
, and title
are used to populate the SPA Image
component.
There are other Image properties exposed (lazyEnabled
, widths
) that allow a developer to create an adaptive and lazy-loading component. The component built in this tutorial is simple and does not use these advanced properties.
Next, create a new folder named Image
under ui.frontend/src/components
.
Beneath the Image
folder create a new file named Image.js
.
Add the following import
statements to Image.js
:
import React, {Component} from 'react';
import {MapTo} from '@adobe/aem-react-editable-components';
Then add the ImageEditConfig
to determine when to show the placeholder in AEM:
export const ImageEditConfig = {
emptyLabel: 'Image',
isEmpty: function(props) {
return !props || !props.src || props.src.trim().length < 1;
}
};
The placeholder will show if the src
property is not set.
Next implement the Image
class:
export default class Image extends Component {
get content() {
return <img className="Image-src"
src={this.props.src}
alt={this.props.alt}
title={this.props.title ? this.props.title : this.props.alt} />;
}
render() {
if(ImageEditConfig.isEmpty(this.props)) {
return null;
}
return (
<div className="Image">
{this.content}
</div>
);
}
}
The above code will render an <img>
based on the props src
, alt
, and title
passed in by the JSON model.
Add the MapTo
code to map the React component to the AEM component:
MapTo('wknd-spa-react/components/image')(Image, ImageEditConfig);
Note the string wknd-spa-react/components/image
corresponds to the location of the AEM component in ui.apps
at: ui.apps/src/main/content/jcr_root/apps/wknd-spa-react/components/image
.
Create a new file named Image.css
in the same directory and add the following:
.Image-src {
margin: 1rem 0;
width: 100%;
border: 0;
}
In Image.js
add a reference to the file at the top beneath the import
statements:
import React, {Component} from 'react';
import {MapTo} from '@adobe/aem-react-editable-components';
require('./Image.css');
Open the file ui.frontend/src/components/import-components.js
and add a reference to the new Image
component:
import './Page/Page';
import './Text/Text';
import './Container/Container';
import './ExperienceFragment/ExperienceFragment';
import './Image/Image'; //add reference to Image component
In import-components.js
comment out the React Core Component Image:
//MapTo('wknd-spa-react/components/image')(ImageV2, {isEmpty: ImageV2IsEmptyFn});
This will ensure that our custom Image component is used instead.
From the root of the project deploy the SPA code to AEM using Maven:
$ cd aem-guides-wknd-spa.react
$ mvn clean install -PautoInstallSinglePackage
Inspect the SPA in AEM. Any Image components on the page should continue to work. Inspect the rendered output and you should see the markup for our custom Image component instead of the React Core Component.
Custom Image component markup
<div class="Image">
<img class="Image-src" src="/content/image-src.jpg">
</div>
React Core Component Image markup
<div class="cmp-image cq-dd-image">
<img src="/content/image-src.jpg" class="cmp-image__image">
</div>
This is a good introduction to extending and implementing your own components.