Improving view performance

To improve the performance of a view, you can add custom Dojo build layers to it.

About this task

With the Dojo build system, your view can include the modules that it depends on in one file or small set of files. These files, each one a layer, reduce the number of HTTP requests that are needed by the application that contains the view. You can use the layers to improve performance by optimizing the loading of the modules without sacrificing modular development. These layers can be custom code or be third-party Dojo layers. The layer files must be built with the Dojo version that is compatible with the Dojo version that your view uses.

IBM® Business Automation Workflow has two modes: debug and non-debug. The isDebug configuration setting in the administrative console determines which mode is in effect. You can specify different layers for each mode.

The build layer definitions must be in a specific format at the start of the inline JavaScript for the view. Process Designer uses this format to generate the appropriate code in the HTML for the coaches that contain the view.

Procedure

If you have custom code, transform it into a Dojo build layer.
For information about Dojo build layers and how to create them by using a transform, see The Dojo Build System.
Prepare your custom JavaScript:
1. Package your Dojo build layer in a .zip file, such as myLayer.zip.
2. Upload that .zip file as a managed web file.
On the Behavior page, add a specific comment block at the beginning of the inline JavaScript.
The comment block consists of two sets of tag blocks:
- @dojoConfigUpdateStart and @dojoConfigUpdateEnd contain normal JavaScript code that updates the global dojoConfig variable before the system loads the Dojo AMD loader.
- @layerRequiredStart and @layerRequiredEnd contain a JSON structure with two optional properties (debug and non-debug). Each property is a JavaScript array type that contains the full name of the layers for each mode. The full name is the package name and the layer file name.
Tip: If you have multiple views that are adding the same layers, copy the comment block into these views. If the layer content is the same, Process Designer combines it so that the generated page contains only one copy of the layer code.
The following example shows the comment block for adding Dojo build layers. For your implementation, replace the name and location values in the Dojo configuration section and replace the names in the layer section.
```
/*  1 
@dojoConfigUpdateStart  2 
	if (dojoConfig.isDebug) {
		dojoConfig.packages.push({
			name: 'com.mycompany.dashboards',  3 
				location: com_ibm_bpm_coach.getManagedAssetUrl('myLayer_debug.zip', 
				com_ibm_bpm_coach.assetType_WEB, 'SYSD') + "/com/mycompany/dashboards"  4 
		});
		} else {
			dojoConfig.packages.push({
				name: 'com.mycompany.dashboards',
					location: com_ibm_bpm_coach.getManagedAssetUrl('myLayer.zip', 
					com_ibm_bpm_coach.assetType_WEB, 'SYSD') + "/com/mycompany/dashboards"
		}); 
	}
@dojoConfigUpdateEnd 
@layerRequiredStart  5 
	{
		"nonDebug":["com.mycompany.dashboards/dashboards",
			"com.mycompany.dashboards/dashboardsMore"],  6 
		"debug":["com.mycompany.dashboards/dashboardsDebug"]
	}
@layerRequiredEnd
* /
```
- 1 Using a comment prevents the comment’s contents from being run as actual inline JavaScript of the view.
- 2 The start of the Dojo configuration section
- 3 The namespace for the package
- 4 The location of the managed file that contains the package
- 5 The start of the layer section
- 6 The name of the package and module within that package for the layer to use in this mode. In this example, the non-debug mode loads two layers and the debug mode loads one layer.
For more examples of how to add layers, see many of the views in the Dashboards toolkit.
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