Canvas Namespace Management Interview Questions & Answers

Methods

Description

Signature

Return Value

Usage

getCanvasUrl()

It retrieves the fully qualified URL of the canvas app.

public String getCanvasUrl()

Type: String

Use this method to get the URL of the canvas app, for example,

http://instance. salesforce.com: 8080/canvas_ app_path/canvas_app.jsp.

getDeveloper Name()

It retrieves the internal API name of the canvas app.

public String getDeveloper Name()

Type: String

Get the API name for the canvas app using this technique. When you expose the canvas app by developing a linked app, you must enter this value in the API Name field.

getName()

It retrieves the name of the canvas app.

public String getName()

Type: String

Get the name of the canvas app using this function.

getNamespace()

It retrieves the current version of the Canvas app.

public String getNamespace()

Type: String

Get the Salesforce namespace prefix connected to the canvas app using this function.

getVersion()

It retrieves the current version of the Canvas app.

public String getVersion()

Type: String

Get the most recent version of the Canvas app using this approach. After you update and republish a canvas app in an organization, this value is updated. The most recent version is always returned when using this method in Developer Edition organizations.

setCanvasUrl Path(newPath)

It overrides the URL of the canvas app for the current request.

public void setCanvasUrl Path(String newPath)

Type: Void

Utilize this technique to modify the canvas app's URL route and query string. Because the supplied URL string will be added to the original canvas URL domain, avoid providing a fully qualified URL.

Methods

Description

Signature

Return Value

Usage

excludeContextTypes()

It enables the exclusion of CanvasRequest context elements that the application does not need.

public Set excludeContext Types()

Type: 

SET

This method must return null or a set of zero or more ContextTypeEnum values. Returning null enables all attributes by default.

ContextTypeEnum values that can be set are

➞Canvas. ContextType Enum. ORGANIZATION

➞Canvas.ContextTypeEnum.RECORD_DETAIL

➞Canvas.ContextTypeEnum.USER

Use this method to define which properties should be turned off when used with the canvas app. When an attribute is deactivated, it will

nullify the canvas context information.

The size of the signed request and canvas context can be reduced to improve performance. Disabled characteristics are not needed to be retrieved by Salesforce, which enhances efficiency.

onRender(renderContext)

It is triggered by the rendering of a canvas app. During the application render phase, it enables the setting and retrieval of context data for the canvas application and environment.

public void onRender (Canvas.RenderContext renderContext)

Type: Void

If used, the canvas app calls this function each time it is rendered. The implementation may use the provided Canvas to set and retrieve context using Canvas. RenderContext

This method is called each time the client retrieves context information or a signed request.

Methods

Description

Signature

Return Value

Usage

addEntityField (fieldName)

When the component appears on a Visualforce, it adds a field to the set of object fields that are returned in the signed request Record object on

a page that is positioned on an item.

public void addEntityField (String fieldName)

Type: Void

You can define which fields should be returned from a connected object when using the component to display a canvas App on a Visualforce page that is associated with an object (posted on the page layout, for example).

In order to add a field to the list of object fields returned in the signed request Record object, use the addEntityField() method. As a rule,

ID is one of the fields in the list. By calling, you can add fields by name or all fields the user can view.

addEntityField('*').

You may view the configured list of fields using Canvas. Environment Context.getEntity Fields().

addEntityFields (fieldNames)

When the component appears on a Visualforce page that is placed on an object, it adds a group of fields to the list of object fields that are returned in the signed request Record object.

public void addEntityFields (Set fieldNames)

Type: Void

You can define which fields should be returned from a connected object when using the component to display a canvas app on a Visualforce page that is associated With an object (posted on the page layout, for example).

To add a group of one or more fields to the list of object fields returned in the signed request Record object, use the addEntityFields() method. ID is included in the list of fields by default. Field names can be added, or you can add all fields that the user has access to view by adding a collection of strings that contain the character “*”.

You may view the configured list of fields using Canvas. Environment Context.getEntity Fields().

getDisplay Location()

It obtains the canvas app's calling location's display location. A value of a Visualforce page as an illustration.

public String getDisplay Location()

Type: String

It obtains the canvas app's calling location's display location. A value of a Visualforce page as an illustration.

Several strings could make up the return value:

➞Chatter—

From the Chatter tab, the Canvas application was launched.

➞ChatterFeed—

A Chatter canvas feed item called the canvas app.

➞ MobileNav – The navigation menu was used to launch the Canvas application.

➞OpenCTI—An Open CTI component called the Canvas application

➞ PageLayout—

An element within a page layout is called the canvas app. One of the subLocation variables can be returned if the displayLocation is PageLayout.

➞ Publisher—  

A canvas custom quick action called the canvas app.

➞ ServiceDesk—

A Salesforce Console component called the Canvas app.

➞Visualforce—

A Visualforce page named the Canvas app.

➞ None—The Canvas App Previewer was used to launch the Canvas App.

Use this technique to find the canvas app's display location.

getEntityFields()

When the component appears on a Visualforce page placed on an object, it retrieves the list of object fields that are returned in the signed request Record object.

public List getEntityFields()

Type: LIST

You can define which fields should be returned from a connected object when using the component to display a canvas app on a Visualforce page that is associated with an object (posted on the page layout, for example).

The list of object fields returned in the signed request Record object can be retrieved using getEntityFields(). ID is included in the list of fields by default. The Canvas can be used to customize the list of fields. EnvironmentContext.addEntityField(fieldName)

getLocationUrl()

It retrieves the canvas app's location URL.

public String getLocationUrl()

Type: String

Use this technique to discover the URL of the page from which the user launched the canvas application. This method, for instance, returns the URL of the Chatter tab, which is comparable to "https://MyDomainName.my.salesforce.com/ ui/core/chatter/ui/ChatterPage," if the user opens your app by clicking a link on the Chatter tab.

getParametersAsJSON()

It retrieves the canvas app's current custom parameters. The parameters are given back as a string of JSON.

public String getParametersAsJSON()

Type: String

Get the most recent custom parameters for the Canvas app using this function. A JSON string with the parameters is returned and can be

The System.JSON. deserializeUntyped(jsonString) method was used to de-serialize the data.

The Canvas. Environment Context.set ParametersAs JSON(jsonString) string can be used to change custom parameters. 

getSublocation()

The canvas app's calling display sublocation is retrieved.

public String getSublocation()

Type: String

several strings could make up the return value:

➞ S1MobileCard Fullview—A mobile card was used to launch the Canvas application.

➞ S1MobileCard Preview—A mobile card preview named the Canvas app. 

To launch the app, the user must click the preview.

➞ S1RecordHome Preview—A record detail page preview called the Canvas app. To launch the app, the user must click the preview.

➞ S1RecordHome Fullview—A page layout called the canvas app.

Use this technique to get the canvas app's display sublocation. Use just if mobile devices can display the main display location.

setParametersAsJSON (jsonString)

It sets the canvas app's custom parameters.

public void setParametersAsJSON(String jsonString)

Type: Void

Set the canvas app's current custom parameters using this function. It is required to supply the parameters in a JSON string. A map can be serialized into a JSON string using the System.JSON.serialize(objectTo Serialize) function.

The custom parameters that are set for the current request will be overwritten when new custom parameters are set. If the current custom parameters need to be changed, use the function getParametersAs JSON() to retrieve the current set of custom parameters, make any necessary changes to the retrieved parameter set, and then use the amended set in the call to setParametersAs JSON ().

A System.Canvas Exception will be raised if the supplied JSON string is longer than 32KB.

Methods

Description

Signature

Return Value

Usage

getApplication Context()

It retrieves the application context data.

public Canvas. Application Context getApplication Context()

Type: Canvas. Application Context

Get the application context information for your canvas app using this method.

getEnvironmentContext()

It retrieves the environment context data.

public Canvas. Environment Context getEnvironmentContext()

Type: Canvas. Environment Context

Get the ambient context information for your Canvas app using this technique.

Methods

Description

Signature

Parameters

Return Value

Usage

mockRender Context (application ContextTest Values, environment ContextTest Values)

Based on the application and environment context settings supplied, it creates and returns a test Canvas. Render Context.

public static Canvas. Render Context mockRender Context(Map

application ContextTest Values, Map environment ContextTest Values)

application ContextTest Values

Type: Map 

environment ContextTest Values

Type: Map

Type: Canvas.RenderContext

To construct a mock Canvas.Render Context, use this function. For testing Canvas.Canvas Lifecycle Handler implementations, use the returned RenderContext in calls to Canvas.Test. testCanvas Lifecycle (lifecycleHandler, mockRender Context).

testCanvas Lifecycle(lifecycleHandler, mockRenderContext)

Activates a Canvas Lifecycle Handler using the supplied Render Context by using the canvas test framework.

public static Void test Canvas Lifecycle (Canvas. Canvas Lifecycle Handler

lifecycle Handler, Canvas. Render Context mockRenderContext)

lifecycle Handler

Type: Canvas. Canvas Lifecycle Handler

mockRender Context

Type: Canvas.RenderContext

Type: Void

To use a mock Canvas.Render Context, use this method to call the implementation of Canvas.Canvas LifecycleHandler.onRender(renderContext)