Скачать или смотреть Solving the Issue of Angular Tree Rows with Embedded Views easily

Learn how to structure `Angular` components effectively while ensuring correct HTML output in tables. This guide addresses a common challenge in embedding views as peers within Angular components.
---
This video is based on the question https://stackoverflow.com/q/70314369/ asked by the user 'Gargoyle' ( https://stackoverflow.com/u/1455351/ ) and on the answer https://stackoverflow.com/a/70316134/ provided by the user 'Mehyar Sawas' ( https://stackoverflow.com/u/5012127/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Angular embed view as peer to current component

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Handling Angular Peer View Embedding for Expandable Tree Rows

Display tables in Angular applications often lead to challenges, especially when using dynamic components like expandable tree rows. Developers frequently encounter problems with the correct placement of table cells (td elements) within their rows (tr elements). This guide addresses a specific problem: how to effectively embed views in Angular components, ensuring that your table structure remains intact and visually appealing.

Understanding the Challenge

In your typical Angular implementation, you might find yourself in a situation where the generated HTML introduces unwanted elements, leading to incorrect table structure. For instance, if you're using a component directly in the tr tag like this:

[[See Video to Reveal this Text or Code Snippet]]

The problem arises when expandable-tree-row ends up being the first child of the tr, leading to empty cells and a disrupted layout. The outcome is not only visually incorrect but also semantically faulty since <td> elements should be direct children of <tr> elements for a proper table structure.

Solutions for Correctly Structuring Expandable Tree Rows

To resolve this issue, we can take two approaches: modifying your current implementation or opting for an alternative use of directives. Here’s a detailed breakdown of both strategies for some clarity.

Solution 1: Using a Template Reference Variable

Instead of placing the expandable-tree-row component directly in the tr, we can utilize an <ng-template> to maintain the correct structure. Follow these steps:

Define an ng-template inside your expandable-tree-row component to hold the view.

[[See Video to Reveal this Text or Code Snippet]]

Use ViewChild to inject the ViewContainerRef for proper querying:

[[See Video to Reveal this Text or Code Snippet]]

Render your templates within this container in the component's lifecycle hook:

[[See Video to Reveal this Text or Code Snippet]]

By following these steps, you ensure that the content gets rendered correctly without leaving behind extraneous elements.

Solution 2: Refactor to a Directive

Alternatively, if you choose to keep the expandable-tree-row as a directive on the tr element, apply the following method:

Change HTML to apply the directive on the tr tag directly.

[[See Video to Reveal this Text or Code Snippet]]

Though this visually aligns your components as expected, you'd need to ensure that the child <td> elements are added correctly within the tr context, maintaining correct hierarchy and structure.

Note on Generated HTML

Regardless of which path you choose, it is essential to note that Angular will alter the generated HTML. With the directive approach, your generated HTML could still lead to an inconsistent tree structure, such as:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

In wrapping up, while using expandable components in Angular tables can introduce complexities in layout, following best practices with <ng-template> and proper child element management allows you to create clean, semantically correct HTML structures. It’s essential for both the design integrity and accessibility of your web applications.

Whichever method you decide to adopt, keep testing your layouts during development to confirm that they meet both visual and structural expectations.