MuleSoft MCD-Level-1 MuleSoft Certified Developer - Level 1 (Mule 4) Exam Practice Test

Correct answer is String is not blank.

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Here’s specifically what is happening here:

1) Payload is successfully set to “Start”

2) The Is Blank String validator creates an Error Object because the payload is string "Start". Execution stops

#[error.description] = “String is not blank”

3) Because no error handler is defined, the Mule default error handler handles the error. Remember, at its heart, the Mule Default Error handler is an error handling scope with just an on error propagate

4) “String is not blank” is the error message returned to the requestor in the body of the HTTP requestHTTP Status Code: 500

Reference Diagram:

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Paths

The path of an HTTP listener can be static, which requires exact matches, or feature placeholders. Placeholders can be wildcards (*), which match against anything they are compared to, or parameters ({param}), which not only match against anything but also capture those values on a URI parameters map.

Take the following example paths for three listeners using a configuration that establishes api/v1 as the base path:

account/mulesoft/main-contact: only match the exact path request http://awesome-company.com/api/v1/account/mulesoft/main-contact

account/{accountId}/main-contact: matches all path requests structured similarly, such as http://awesome-company.com/api/v1/account/salesforce/main-contact , and save salesforce as the value of accountId.

account/{accountId}/*: matches all path requests different from main-contact, such as http://awesome-company.com/api/v1/account/mulesoft/users , and save mulesoft as the value of accountId.

Mule Ref Doc : https://docs.mulesoft.com/http-connector/1.6/http-listener-ref#paths

1. Set Payload “Start”

2. 'Is Balnk String' Creates an Error object with #[error.description] =“String is not blank”

3. Default Error Handler catches and Propagates error

4. 'On Error Propogate' is 'RED IN RED OUT'. It Returns Status Code : 500 & #[error.description]

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Correct answer is String is not blank. Because validation component will throw an error as payload is not blank.

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This is a trick question.

You can call only flows from DataWeave using lookup function. Note that lookup function does not support calling subflows.

A subflow needs a parent context to inherit behaviors from such as exception handling, which a flow does not need

Hence correct answer is Not possible in Mule 4

Choice router finds the FIRST true condition, then distribute the event to the ONE matched route.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.1/choice-router-concept

The Choice router dynamically routes messages through a flow according to a set of DataWeave expressions that evaluate message content. Each expression is associated with a different routing option. The effect is to add conditional processing to a flow, similar to an if/then/else code block in most programming languages.

Only one of the routes in the Choice router executes, meaning that the first expression that evaluates to true triggers that route’s execution and the others are not checked. If none of the expressions are true, then the default route executes.

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Lets revise few concepts RAML which can help us to find the answer of this question.

URI Parameters

Lets have a look at below example.

• /foos:
• /{id}:
• /name/{name}:

Here, the braces { } around property names define URI parameters. They represent placeholders in each URI and do not reference root-level RAML file properties as we saw above in the baseUri declaration. The added lines represent the resources /foos/{id} and /foos/name/{name}.

Query Parameters

Now we'll define a way to query the foos collection using query parameters. Note that query parameters are defined using the same syntax that we used above for data types:

• /foos:
• get:
• description: List all Foos matching query criteria, if provided;
• otherwise list all Foos
• queryParameters:
• name?: string
• ownerName?: string

Based on the above information , below is the only option which defines storeid as uri parameter and department as query parameter.

• /{storeId}:
• get:
• queryParameter:
• department:

Setting Breakpoints

To set breakpoints, right-click a building block, then select Toggle Breakpoint.

Studio applies a red dot to the building block’s icon on the canvas.

When you run your application in Debug mode, Studio stops the flow execution at the breakpoint you have set, allowing you to check the Mule Event content in the Mule Debugger View.

Mule Ref Doc : Setting Breakpoints | MuleSoft Documentation

APIKIt Creates a separate flow for each HTTP method. Hence 4 private flows would be generated.

MuleSoft Documentation Referrence : https://docs.mulesoft.com/mule-runtime/4.3/build-application-from-api

Empty array is returned when no rows are matched.

MuleSoft Doc Ref : https://docs.mulesoft.com/db-connector/1.9/database-connector-select

Creates reusable APIs and assets designed to be consumed by other business units

Correct answer is Publish the API to Anypoint Exchange

Anypoint Exchange makes this possible by making it discoverable in below ways

1) In private exchange for internal developers

2) In a public portal for external developers/clients

Here is diagram created by me to help you understand sequence:

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* When a client application is registered in Anypoint Platform, a pair of credentials consisting of a client ID and client secret is generated.

* When the client application requests access to an API, a contract is created between the application and that API.

* An API that is protected with a Client ID Enforcement policy is accessible only to applications that have an approved contract.

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Correct Answer: In the organization's public API portal in Anypoint Exchange, from an approved client application for the API proxy

WSDL is used to define the contract in case of SOAP . RAML/OAS is used to REST services

Correct answer is vars."customer"."firstName"

Please note that you can also access firstName using this syntax vars.customer.firstName.

Mule Ref Doc : Variables in Mule Apps | MuleSoft Documentation

Exchange is the odd man out here. Rest all are type of asset

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API portal are created by API Exchange and cannot be created by Design Center

The First Successful router iterates through a list of configured processing routes until one of the routes executes successfully. This is sequential execution. In all other options mentioned in the question ,we can achieve parallel execution.

Correct answer is Save the payload from the Database SELECT operation to a variable

Response from HTTP request will override the payload and hence response of database SELECT can be lost. Best way to preserve is to assign payload of first operation to variable using TransformMessage.

Correct answer is APP: API RESOURCE NOT FOUND

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1) A web client submits the request to the HTTP Listener.

2) The HTTP Request throws an "HTTP:NOT_FOUND" error, execution halts.

3) The On Error Propagate error Handler handles the error. In this case ,HTTP:NOT_FOUND error is mapped to custom error APP:API_RESOURCE_NOT_FOUND. This error processor sets payload to APP:API_RESOURCE_NOT_FOUND.

4) “APP:API_RESOURCE_NOT_FOUND. ” is the error message returned to the requestor in the body of the HTTP request with HTTP Status Code: 500

Reference Diagram:

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* To use custom modules, you need to import the module or functions you want to use by adding the import directive to the head of your DataWeave script, for example:

1) Does not identify any functions to import from the String module:

import dw::core::Strings

2) To identify a specific function to import from the String module:

import camelize, capitalize from dw::core::Strings

3) To import all functions from the String module:

import * from dw::core::Strings

The way you import a module impacts the way you need to call its functions from a DataWeave script. If the directive does not list specific functions to import or use * from to import all functions from a function module, you need to specify the module when you call the function from your script.

* In given scenario, it's mentioned to import all of the WebStore.dwl

So correct answer is:

The flow can be described as below. 1) First HTTP POST requets is made in which paylaod is set to 1 and it gets returned to our mail flow. 2) Second call is initiated for JMS Publish Consume JMS: num1 which add 1 to the payload which makes it as 2. Note that pubih consume is a synchronous operation. Hence paylaod is returned to main flow. 3) Third call is initiated for JMS Publish JMS: num2 which add 1 to the payload . Note that pubih is asynchronous operation. Hence paylaod is never returned to main flow. So payload in main flow is still 2. 4) Finally Set Payload increments payload by 1 making payload as 3 which is returned by the flow. Hence option 3 is the correct answer.

URI parameter is basically used to identify a specific resource or resources

* Here we want to update details about specific department, so question is asking 'How to use URI parameter' in RAML

* Correct answer is

/departments:

/{deptId}:

patch:

Correct answer is process layer as all the orchestration and transformation logic should be in process layer as per Mulesoft's recommended approach for API led connectivity.

API-led connectivity is a methodical way to connect data to applications through reusable and purposeful APIs. These APIs are developed to play a specific role – unlocking data from systems, composing data into processes, or delivering an experience.

What are the APIs that enable API-led connectivity?

API-led connectivity provides an approach for connecting and exposing assets. With this approach, rather than connecting things point-to-point, every asset becomes a managed API – a modern API, which makes it discoverable through self-service without losing control.

The APIs used in an API-led approach to connectivity fall into three categories:

System APIs – these usually access the core systems of record and provide a means of insulating the user from the complexity or any changes to the underlying systems. Once built, many users, can access data without any need to learn the underlying systems and can reuse these APIs in multiple projects.

Process APIs – These APIs interact with and shape data within a single system or across systems (breaking down data silos) and are created here without a dependence on the source systems from which that data originates, as well as the target channels through which that data is delivered.

Experience APIs – Experience APIs are the means by which data can be reconfigured so that it is most easily consumed by its intended audience, all from a common data source, rather than setting up separate point-to-point integrations for each channel. An Experience API is usually created with API-first design principles where the API is designed for the specific user experience in mind.

Option 1 is the only correct choice due to two reasons. 1) Concatenation is always with ++ sign and not with + sign which makes option 2 and 3 wrong 2) hearders can be accessed with attributes. headers and not with only headers which makes option 4 incorrect

Web Services Description Language. WSDL is used to describe SOAP based web services

This kind of questions are best solved with filtering technique. Key thing to note here is XML attributes are always access by @ notation. So in this example orderId can be accessed as @OrderId which makes option 3 and option 4 false. Now difference in optin and option 2 is in mapping of lineItemPrice. Correct syntax to format a String in Numbse is value.price as Number. Hence option 2 is correct

client-id-required enforces clients to add client_id and client_secret.

Please refer to below steps.

• Add a section called traits: at the root level to define query parameters:
• traits:
• - client-id-required:
• queryParameters:
• client_id:
• type: string
• client_secret:
• type: string
• 2) Reference the trait in each of the methods to specify that each of the methods require these query parameters. After each method in the RAML file, add is: [client-id-required]. For example:
• /users:
• get:
• is: [client-id-required]
• description: Gets a list of JSONPlaceholder users.

Correct answer is */status as it is the correct way to use wildcards while configuring path value in HTTP listener

URL parameters are always accessed using { } like => {customerID}

By default, Debugger listens for incoming TCP connections on localhost port 6666 You can change this in a project's run configuration.

MuleSoft Doc Ref : https://docs.mulesoft.com/studio/7.5/visual-debugger-concept

Correct answer is Not needed as dw::core module is included by default. We don't need to include it explicitly

Correct answer is The API interfaces are specified at a granularity intended for developers to consume specific aspect of integration processes

In this case as outbound call is made using HTTP: POST /child , all attributes will be replaced by this invocation. Hence query parameter will not be accessible at logger.

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Here’s specifically what is happening here:

1) Payload is successfully set to “Before”

2) Is null validation is used which will pass the message only if payload is null. In this case as payload is not null, it creates an Error Object. Flow execution stops

#[error.description] = “Validation error”

3) Because no error handler is defined, the Mule default error handler handles the error

4) “Validation error” is the error message returned to the requestor in the body of the HTTP request with HTTP Status Code: 500

Reference diagram:

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Debugger can be used to debug applications to see event data movine from one flow to other

Flow Reference Component

Flow Reference routes the Mule event to another flow or subflow, executes all processors in the referenced flow, and then routes the event back within the same Mule application. The following diagram shows the order of processing when one flow references another:

When the main flow is triggered, the Mule event travels through and executes the flow until the event reaches the Flow Reference. The event then travels through and executes the referenced flow from beginning to end, and then returns to the main flow.

This process enables you to treat the entire referenced flow like a single component in your current flow.

Mule Ref Doc : https://docs.mulesoft.com/mule-runtime/4.3/flowref-about

Correct answer is

• payload
• quantity var
• color query param

Correct syntax to use where clause is WHERE city = :city AND state = :state

This question validates knowledge on using dynamic queries in DB select operation.

Configure Dynamic Queries in the Select Operation

When you need to parameterize not only the WHERE clause but also parts of the query itself (for example, queries that compare tables that depend on a condition, or complex queries for which the project table columns need to vary), you can configure dynamic queries.

In the following example, you configure a dynamic query by using a full expression with a string in which the table depends on a variable $(vars.table). Although some of the query text is dynamic ("SELECT * FROM $(vars.table)), the WHERE clause still defines the WHERE condition using input parameters: in this case, WHERE name = :name.

In your Studio flow, select the Select operation.

In the operation configuration screen, set the SQL Query Text field to SELECT * FROM $(vars.table) WHERE name = :name.

Set the Input Parameters field to {'name' : payload}.

The following screenshot shows the configuration in Studio:

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Figure 3. Dynamic query configuration

In the XML editor, the  configuration looks like this:

• #["SELECT * FROM $(vars.table) WHERE name = :name"]
• #[{'name' : payload}]

You can apply input parameters only to parameters in a WHERE clause. To modify any other part of the query, use the DataWeave interpolation operator.

Mule Ref Doc: Query a Database Examples - Mule 4 | MuleSoft Documentation

In General > Request > Query Parameters, click the plus icon (+) to add a parameter to a request. Type a name and value for the parameter or use a DataWeave expression to define the name and value.

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Correct answer is Change the method attributes value to "POST".

It can be fixed in either of the two ways as below.

1) Changing method attribute to POST in ClientRequestFlow

2) Setting allowedMethods as PUT in ShippingFlow (but doesn't fit as question mentions about changing ClientRequestFlow)

Application properties can be defined in .yaml or in .properties file.

MuleSoft Doc Ref : https://docs.mulesoft.com/mule-runtime/4.3/configuring-properties#supported_files

Correct answer is Array.

Flatten turns a set of subarrays (such as [ [1,2,3], [4,5,[6]], [], [null] ]) into a single, flattened array (such as [ 1, 2, 3, 4, 5, [6], null ]).

This example defines three arrays of numbers, creates another array containing those three arrays, and then uses the flatten function to convert the array of arrays into a single array with all values.

Source

%dw 2.0

output application/json

var array1 = [1,2,3]

var array2 = [4,5,6]

var array3 = [7,8,9]

var arrayOfArrays = [array1, array2, array3]

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flatten(arrayOfArrays)

Output

[ 1,2,3,4,5,6,7,8,9 ]