To define the UI components used on a page, you can use browser built-in developer tools, or install additionally a plugin, for example Knockoutjs context debugger for Google Chrome.
Debugging using Knockout.js plugin
To install the knockout debugging plugin for Google Chrome, take the following steps:
- Open your Google Chrome browser.
- Expand Google Chrome options drop-down (hamburger in upper right).
- Select Settings.
- In left pane, select Extensions.
- Scroll to end of the page and click Get more extensions link.
- In the Search field write Knockoutjs context debugger and press the Enter key.
- In the result, find the extension named Knockoutjs context debugger (usually the first result), and click Add to Chrome.
To define the UI component using the plugin:
- Open the required page in Chrome.
- Point to the required element on the page, right-click and select Inspect. The developer tools panel opens.
- In the right column of the panel, click the Knockout context tab. The tab displays the name and the configuration of the UI component instance.
A simple example:
- Launch Magento Admin.
- Navigate to Products > Catalog and click Add Product. The product creation page opens.
- Right-click on the Product Name field and click Inspect. Go to the Knockout context tab. Here you can see the full context of the field, where you can find JS component file, component name, etc.
Debugging using pure Knockout
To retrieve the context within markup, you can also use the instance of Knockout:
At first we need to get a Knockout instance from the browser console. To do so, use the RequireJS ID
Now we have Knockout instance in the
ko variable. We can use it to get a context of any DOM element.
$0 is a special variable in browser console. It contains a link to a DOM element that is last inspected.
Debugging using the uiRegistry
uiRegistry is a in-memory storage. Plain storage of entities by keys. Implements the
To debug the UI component JS, we first need to get a
uiRegistry instance from the browser console. To do so, use the RequireJs ID
In the browser console enter the following:
Now we have
uiRegistry instance in the
registry variable. We can use it to get an instance of any component.
Lets look what we have in component variable. It keeps component context with all properties, we can see component file, component name and so on.