Movie Lists and Pagination

Optional Lesson

This lesson is optional and will not count towards your achievement. To view the completed code, check out the 11-movie-lists branch.

In this challenge, you will implement the remaining methods in the MovieService for retrieving a list of movies:

  • getByGenre - should return a paginated list of movies that are listed in a particular Genre

  • getForActor - should return a paginated list of movies that a particular Person has acted in

  • getForDirector - should return a paginated list of movies that a particular Person has directed

These methods are very similar to the all() method which returns a full list, but with a different pattern in the MATCH clause.

For each subtask, we will provide you with the pattern required to run in the Cypher statement, plus any additional parameters that are required for the query to run.

All you need to do is take the code from the all() method and modify the pattern in the first line of the Cypher statement in the first argument of the tx.run() call, then if necessary add the additional parameters to the second argument.

If you get stuck at any point, you can click to reveal the completed solution or skip to the bottom for instructions on how to checkout the branch with the working solution.

Open src/services/movie.service.js

getByGenre

The getByGenre() method returns a paginated list of movies that are listed within a certain genre.

js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/main/src/services/movie.service.js[tag=getByGenre]

Update the getByGenre() method to use the following Cypher Pattern:

cypher
MATCH (m:Movie)-[:IN_GENRE]->(:Genre {name: $name})

The tx.run() call will need to include the name property, which represents the name of the genre.

Click to reveal the completed getByGenre() method

Find the getByGenre() method in src/services/movie.service.js and modify the function to find a list of movies by genre.

js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/11-movie-lists/src/services/movie.service.js[tag=getByGenre]

getForActor

The getForActor() method returns a paginated list of movies that a person has acted in.

js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/main/src/services/movie.service.js[tag=getForActor]

Find the getForActor() method in src/services/movie.service.js and modify the function to find a list of movies by actor.

The pattern required in the MATCH clause will be:

cypher
MATCH (:Person {tmdbId: $id})-[:ACTED_IN]->(m:Movie)

You will have to include the additional parameter id - The tmdbId property relating to the actor.

Click to reveal the completed getForActor() method
js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/11-movie-lists/src/services/movie.service.js[tag=getForActor]

getForDirector

The getForDirector() method returns a paginated list of movies that a person has directed.

js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/main/src/services/movie.service.js[tag=getForDirector]

Find the getForDirector() method in src/services/movie.service.js and modify the function to find a list of movies by director.

The pattern required in the MATCH clause will be:

cypher
MATCH (:Person {tmdbId: $id})-[:DIRECTED]->(m:Movie)

You will have to include the additional parameter id - The tmdbId property relating to the director.

Click to reveal the completed getForDirector() method
js
src/services/movie.service.js
Unresolved directive in lesson.adoc - include::https://raw.githubusercontent.com/neo4j-graphacademy/llm-chatbot-python/11-movie-lists/src/services/movie.service.js[tag=getForDirector]

Testing

To test that this functionality has been correctly implemented, run the following code in a new terminal session:

sh
Running the test
npm run test 11

The test file is located at test/challenges/11-movie-lists.spec.js.

Are you stuck? Click here for help

If you get stuck, you can see a working solution by checking out the 11-movie-lists branch by running:

sh
Check out the 11-movie-lists branch
git checkout 11-movie-lists

You may have to commit or stash your changes before checking out this branch. You can also click here to expand the Support pane.

Verifying the Test

1. How many films has Francis Ford Copolla directed?

The final test, titled should find films directed by Francis Ford Coppola, logs out the number of results returned from the API for films directed by Francis Ford Copolla.

Enter the number in the box below and click Check Answer.

  • ✓ 16

Hint

You can also find the answer by running the following Cypher statement:

cypher
MATCH (p:Person {tmdbId: "1776"})
RETURN count { (p)-[:DIRECTED]->() }

Copy the answer without any quotes or whitespace.

Solution

The answer is 16

Lesson Summary

In this Challenge, you modified the functions in the MovieService to return lists of movies.

In the next Challenge, you will implement the findById() method.