alfresco-ng2-components/docs/tutorials/content-metadata-component.md

Title, Level

Title	Level
Content metadata component	Advanced

Content metadata component

In this tutorial you will learn how to work with the ContentMetadataComponent.

This component is used to render the standard and custom metadata of generic content item (called a node) stored in Alfresco Content Services. With the usual approach "learning by doing", you will see here some practical examples you might find useful in your own applicatioin. As a starting point, we will use and customize the Alfresco Content App.

About the ContentMetadataComponent

As described in the ContentMetadataComponent documentation, the adf-content-metadata-card tag has some useful attributes, included the preset attribute, which is used to point to a collection of aspects/properties to render.

Below, you can see the preset value requesting to render all the available aspects/properties:

<adf-content-metadata-card
    [node]="..."
    [preset]="'*'">
</adf-content-metadata-card>

As another example, you can see the preset value requesting to render all the available aspects/properties related to a specific configuration, named custom:

<adf-content-metadata-card
    [node]="..."
    [preset]="'custom'">
</adf-content-metadata-card>

All the preset configurations are defined in one single configuration file named app.config.json, stored in the src folder of the project. The app.config.json file contains all the configurations of the ADF application, including a section named content-metadata, which is used to store the presets. The following JSON excerpt gives an example of configuration for the preset named custom:

"content-metadata": {
    "presets": {
        "custom": [
            {
                "title": "APP.CONTENT_METADATA.EXIF_GROUP_TITLE",
                "items": [
                    {
                        "aspect": "exif:exif",
                        "properties": [
                            "exif:pixelXDimension",
                            "exif:pixelYDimension",
                            ...
                        ]
                    }
                ]
            }
        ]
    }
},

This configuration will show all the listed properties prefixed with exif:* in a group titled with the value of the variable APP.CONTENT_METADATA.EXIF_GROUP_TITLE for the aspect exif:exif. Since this aspect is not related to the node, the component will simply ignore the rendering and nothing will be displayed for these properties. In other words: the aspects to be displayed are calculated as an intersection of the preset's aspects and the aspects related to the node.

Adding and using a new preset configuration

In this example we will add a new preset configuration and see how it looks in the user interface.

Adding a new preset configuration

To add a new preset configuration, edit the src/app.config.json file and locate the content-metadata section. Then, append the following JSON to the presets content and save the file:

...,
"content-metadata": {
    "presets": {
        "custom": [...],
        "my-preset": [
            {
                "title": "This is my preset",
                "items": [
                    {
                        "aspect": "st:siteContainer",
                        "properties": ["*"]
                    }
                ]
            }
        ]
    }
},

Note: As an alternative to "properties": ["*"] (which matches all the properties of the st:siteContainer aspect), you can use "properties": ["st:componentId"], which will render one property only.

Using the my-preset configuration

Now that the my-preset configuration is defined, let's use it in a view of the ADF application. As an example, let's edit the files view, stored in the src/app/files folder. Specifically, let's change the files.component.html file as follows:

<adf-content-metadata-card
    ...
    [preset]="'my-preset'">
</adf-content-metadata-card>

Properties

Name	Type	Default value	Description
readOnly	boolean	false	(optional) This flag sets the metadata in read only mode preventing changes.

Viewing the result

After saving the html file, open the ADF app in a browser and dive into the Personal Files > Sites > swsdp folder of the Alfresco's repository. Once there, select the documentLibrary folder (one click only) and click on the view details icon (the menu_open icon on the top right). Scrolling down the metadata tab on the right. You will see different panels: Properties (already there by default), Tags, Categories and grouped properties.

In the following screenshot you can see how the result should look:

To check it out, double click on the documentLibrary folder and select (with one click) the Presentations folder. You should see the This is my preset group disappear from the metadata panel, because the node doesn't have the st:siteContainer aspect.