CODEWITHSUNDEEP
javascriptreactjs
3therk1ll
3therk1ll

Reputation: 2421

'if' statement in promise `then` section

Ok so I am stuck on what I thought would be simpler and maybe I've just been looking at the terminal too long!

I have submitted a project for the React course I am doing and in the code review an improvement was suggested by the reviewer to add an if statement check to then portion of a promise.

This is what the reviewer said:

Inside 'then' part of the promise check if(query === this.state.query) to ensure you are not going to replace the contents to an old response.

bookSearch(query) {
      if (query.length > 0)
        BooksAPI.search(query)
        .then(searchResults => this.setState(currentState => ({ 
          results: this.updateExistingShelves(searchResults)
        })));
     }

I have tried adding an if in but I keep getting syntax errors. What is the correct way to do this?

I cannot add it to the initial if in this method as it messes up the first query and nothing ever gets into the BooksAPI call

Upvotes: 0

Views: 89

Answers (2)

Rohith Murali
Rohith Murali

Reputation: 5669

You can add an if inside then like,

bookSearch(query) {
      if (query.length > 0)
        BooksAPI.search(query)
        .then(searchResults => {
            if(query === this.state.query){
              this.setState(currentState => (
              { 
                 results: this.updateExistingShelves(searchResults)
              }))
            }
        );
     }

Upvotes: 1

Rodius
Rodius

Reputation: 2311

I think this is what he means:

bookSearch(query) {
      if (query.length > 0)
        BooksAPI.search(query)
        .then(searchResults => {
          if (query === this.state.query) {
            this.setState({ results: this.updateExistingShelves(searchResults) });
          } 

        });
     }

Upvotes: 1

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