dynamically import a React Component if that file exists, otherwise show a default message










2















I want to conditionally import a React Component if the file exists and if not do something else. For example show a default view or message.



I tried this:






let Recipe;
try
Recipe = require(`docs/app/Recipes/$props.componentName`);
catch (e)
Recipe = () => <div>Not found</div>;





However the linter is complaining that I should not try to dynamicaly require a file, but use a string literal instead.



Is there a cleaner approach to to what I'm trying to achieve?










share|improve this question




























    2















    I want to conditionally import a React Component if the file exists and if not do something else. For example show a default view or message.



    I tried this:






    let Recipe;
    try
    Recipe = require(`docs/app/Recipes/$props.componentName`);
    catch (e)
    Recipe = () => <div>Not found</div>;





    However the linter is complaining that I should not try to dynamicaly require a file, but use a string literal instead.



    Is there a cleaner approach to to what I'm trying to achieve?










    share|improve this question


























      2












      2








      2


      3






      I want to conditionally import a React Component if the file exists and if not do something else. For example show a default view or message.



      I tried this:






      let Recipe;
      try
      Recipe = require(`docs/app/Recipes/$props.componentName`);
      catch (e)
      Recipe = () => <div>Not found</div>;





      However the linter is complaining that I should not try to dynamicaly require a file, but use a string literal instead.



      Is there a cleaner approach to to what I'm trying to achieve?










      share|improve this question
















      I want to conditionally import a React Component if the file exists and if not do something else. For example show a default view or message.



      I tried this:






      let Recipe;
      try
      Recipe = require(`docs/app/Recipes/$props.componentName`);
      catch (e)
      Recipe = () => <div>Not found</div>;





      However the linter is complaining that I should not try to dynamicaly require a file, but use a string literal instead.



      Is there a cleaner approach to to what I'm trying to achieve?






      let Recipe;
      try
      Recipe = require(`docs/app/Recipes/$props.componentName`);
      catch (e)
      Recipe = () => <div>Not found</div>;





      let Recipe;
      try
      Recipe = require(`docs/app/Recipes/$props.componentName`);
      catch (e)
      Recipe = () => <div>Not found</div>;






      javascript reactjs webpack jsx eslint






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited Nov 16 '18 at 6:56







      rubentd

















      asked Nov 15 '18 at 19:06









      rubentdrubentd

      1,089922




      1,089922






















          2 Answers
          2






          active

          oldest

          votes


















          3














          The problem is this approach is that it kills bundle optimizations and includes all files from docs/app/Recipes/ into a bundle, even if they aren't used.



          A better way to write this is to use <React.Suspense> and React.lazy:



          const Recipe = React.lazy(() =>
          import(`docs/app/Recipes/$props.componentName`)
          .catch(() => ( default: () => <div>Not found</div> ))
          );


          Which is used as:



          <React.Suspense fallback='loading...'><Recipe/></React.Suspense>


          A cleaner way to do this and avoid linter error is to have a map of possible components:



          import Foo from 'docs/app/Recipes/Foo';
          import Bar from 'docs/app/Recipes/Bar';
          ...

          const componentsMap = Foo, Bar ;

          ...

          const Recipe = componentsMap[props.componentName] || () => <div>Not found</div>;


          In this case props.componentName can be validated if needed.






          share|improve this answer
































            1














            in fact there is. With the recent release of React v16.6.0 "lazy code splitting" was introduced. This is how it works, it makes sense to use it together with reacts' 'suspense':



             import React, lazy, Suspense from 'react';
            const Recipe = lazy(() =>import(`./docs/app/Recipes/$props.componentName`));

            function SomeComponent()
            return (
            <Suspense fallback=<Spinner/>>
            <Recipe />
            </Suspense>
            );



            To handle the case that the component isn't found you can use Error Boundaries. You would wrap your component with it like this:



            <ErrorBoundary>
            <Suspense fallback=<Spinner/>>
            <Recipe />
            </Suspense>
            </ErrorBoundary>


            Best you read more about it directly on the react docs I linked above.






            share|improve this answer






















              Your Answer






              StackExchange.ifUsing("editor", function ()
              StackExchange.using("externalEditor", function ()
              StackExchange.using("snippets", function ()
              StackExchange.snippets.init();
              );
              );
              , "code-snippets");

              StackExchange.ready(function()
              var channelOptions =
              tags: "".split(" "),
              id: "1"
              ;
              initTagRenderer("".split(" "), "".split(" "), channelOptions);

              StackExchange.using("externalEditor", function()
              // Have to fire editor after snippets, if snippets enabled
              if (StackExchange.settings.snippets.snippetsEnabled)
              StackExchange.using("snippets", function()
              createEditor();
              );

              else
              createEditor();

              );

              function createEditor()
              StackExchange.prepareEditor(
              heartbeatType: 'answer',
              autoActivateHeartbeat: false,
              convertImagesToLinks: true,
              noModals: true,
              showLowRepImageUploadWarning: true,
              reputationToPostImages: 10,
              bindNavPrevention: true,
              postfix: "",
              imageUploader:
              brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
              contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
              allowUrls: true
              ,
              onDemand: true,
              discardSelector: ".discard-answer"
              ,immediatelyShowMarkdownHelp:true
              );



              );













              draft saved

              draft discarded


















              StackExchange.ready(
              function ()
              StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53326353%2fdynamically-import-a-react-component-if-that-file-exists-otherwise-show-a-defau%23new-answer', 'question_page');

              );

              Post as a guest















              Required, but never shown

























              2 Answers
              2






              active

              oldest

              votes








              2 Answers
              2






              active

              oldest

              votes









              active

              oldest

              votes






              active

              oldest

              votes









              3














              The problem is this approach is that it kills bundle optimizations and includes all files from docs/app/Recipes/ into a bundle, even if they aren't used.



              A better way to write this is to use <React.Suspense> and React.lazy:



              const Recipe = React.lazy(() =>
              import(`docs/app/Recipes/$props.componentName`)
              .catch(() => ( default: () => <div>Not found</div> ))
              );


              Which is used as:



              <React.Suspense fallback='loading...'><Recipe/></React.Suspense>


              A cleaner way to do this and avoid linter error is to have a map of possible components:



              import Foo from 'docs/app/Recipes/Foo';
              import Bar from 'docs/app/Recipes/Bar';
              ...

              const componentsMap = Foo, Bar ;

              ...

              const Recipe = componentsMap[props.componentName] || () => <div>Not found</div>;


              In this case props.componentName can be validated if needed.






              share|improve this answer





























                3














                The problem is this approach is that it kills bundle optimizations and includes all files from docs/app/Recipes/ into a bundle, even if they aren't used.



                A better way to write this is to use <React.Suspense> and React.lazy:



                const Recipe = React.lazy(() =>
                import(`docs/app/Recipes/$props.componentName`)
                .catch(() => ( default: () => <div>Not found</div> ))
                );


                Which is used as:



                <React.Suspense fallback='loading...'><Recipe/></React.Suspense>


                A cleaner way to do this and avoid linter error is to have a map of possible components:



                import Foo from 'docs/app/Recipes/Foo';
                import Bar from 'docs/app/Recipes/Bar';
                ...

                const componentsMap = Foo, Bar ;

                ...

                const Recipe = componentsMap[props.componentName] || () => <div>Not found</div>;


                In this case props.componentName can be validated if needed.






                share|improve this answer



























                  3












                  3








                  3







                  The problem is this approach is that it kills bundle optimizations and includes all files from docs/app/Recipes/ into a bundle, even if they aren't used.



                  A better way to write this is to use <React.Suspense> and React.lazy:



                  const Recipe = React.lazy(() =>
                  import(`docs/app/Recipes/$props.componentName`)
                  .catch(() => ( default: () => <div>Not found</div> ))
                  );


                  Which is used as:



                  <React.Suspense fallback='loading...'><Recipe/></React.Suspense>


                  A cleaner way to do this and avoid linter error is to have a map of possible components:



                  import Foo from 'docs/app/Recipes/Foo';
                  import Bar from 'docs/app/Recipes/Bar';
                  ...

                  const componentsMap = Foo, Bar ;

                  ...

                  const Recipe = componentsMap[props.componentName] || () => <div>Not found</div>;


                  In this case props.componentName can be validated if needed.






                  share|improve this answer















                  The problem is this approach is that it kills bundle optimizations and includes all files from docs/app/Recipes/ into a bundle, even if they aren't used.



                  A better way to write this is to use <React.Suspense> and React.lazy:



                  const Recipe = React.lazy(() =>
                  import(`docs/app/Recipes/$props.componentName`)
                  .catch(() => ( default: () => <div>Not found</div> ))
                  );


                  Which is used as:



                  <React.Suspense fallback='loading...'><Recipe/></React.Suspense>


                  A cleaner way to do this and avoid linter error is to have a map of possible components:



                  import Foo from 'docs/app/Recipes/Foo';
                  import Bar from 'docs/app/Recipes/Bar';
                  ...

                  const componentsMap = Foo, Bar ;

                  ...

                  const Recipe = componentsMap[props.componentName] || () => <div>Not found</div>;


                  In this case props.componentName can be validated if needed.







                  share|improve this answer














                  share|improve this answer



                  share|improve this answer








                  edited Jan 14 at 9:34

























                  answered Nov 15 '18 at 19:43









                  estusestus

                  77.4k23114234




                  77.4k23114234























                      1














                      in fact there is. With the recent release of React v16.6.0 "lazy code splitting" was introduced. This is how it works, it makes sense to use it together with reacts' 'suspense':



                       import React, lazy, Suspense from 'react';
                      const Recipe = lazy(() =>import(`./docs/app/Recipes/$props.componentName`));

                      function SomeComponent()
                      return (
                      <Suspense fallback=<Spinner/>>
                      <Recipe />
                      </Suspense>
                      );



                      To handle the case that the component isn't found you can use Error Boundaries. You would wrap your component with it like this:



                      <ErrorBoundary>
                      <Suspense fallback=<Spinner/>>
                      <Recipe />
                      </Suspense>
                      </ErrorBoundary>


                      Best you read more about it directly on the react docs I linked above.






                      share|improve this answer



























                        1














                        in fact there is. With the recent release of React v16.6.0 "lazy code splitting" was introduced. This is how it works, it makes sense to use it together with reacts' 'suspense':



                         import React, lazy, Suspense from 'react';
                        const Recipe = lazy(() =>import(`./docs/app/Recipes/$props.componentName`));

                        function SomeComponent()
                        return (
                        <Suspense fallback=<Spinner/>>
                        <Recipe />
                        </Suspense>
                        );



                        To handle the case that the component isn't found you can use Error Boundaries. You would wrap your component with it like this:



                        <ErrorBoundary>
                        <Suspense fallback=<Spinner/>>
                        <Recipe />
                        </Suspense>
                        </ErrorBoundary>


                        Best you read more about it directly on the react docs I linked above.






                        share|improve this answer

























                          1












                          1








                          1







                          in fact there is. With the recent release of React v16.6.0 "lazy code splitting" was introduced. This is how it works, it makes sense to use it together with reacts' 'suspense':



                           import React, lazy, Suspense from 'react';
                          const Recipe = lazy(() =>import(`./docs/app/Recipes/$props.componentName`));

                          function SomeComponent()
                          return (
                          <Suspense fallback=<Spinner/>>
                          <Recipe />
                          </Suspense>
                          );



                          To handle the case that the component isn't found you can use Error Boundaries. You would wrap your component with it like this:



                          <ErrorBoundary>
                          <Suspense fallback=<Spinner/>>
                          <Recipe />
                          </Suspense>
                          </ErrorBoundary>


                          Best you read more about it directly on the react docs I linked above.






                          share|improve this answer













                          in fact there is. With the recent release of React v16.6.0 "lazy code splitting" was introduced. This is how it works, it makes sense to use it together with reacts' 'suspense':



                           import React, lazy, Suspense from 'react';
                          const Recipe = lazy(() =>import(`./docs/app/Recipes/$props.componentName`));

                          function SomeComponent()
                          return (
                          <Suspense fallback=<Spinner/>>
                          <Recipe />
                          </Suspense>
                          );



                          To handle the case that the component isn't found you can use Error Boundaries. You would wrap your component with it like this:



                          <ErrorBoundary>
                          <Suspense fallback=<Spinner/>>
                          <Recipe />
                          </Suspense>
                          </ErrorBoundary>


                          Best you read more about it directly on the react docs I linked above.







                          share|improve this answer












                          share|improve this answer



                          share|improve this answer










                          answered Nov 15 '18 at 19:35









                          Fabian HinsenkampFabian Hinsenkamp

                          1716




                          1716



























                              draft saved

                              draft discarded
















































                              Thanks for contributing an answer to Stack Overflow!


                              • Please be sure to answer the question. Provide details and share your research!

                              But avoid


                              • Asking for help, clarification, or responding to other answers.

                              • Making statements based on opinion; back them up with references or personal experience.

                              To learn more, see our tips on writing great answers.




                              draft saved


                              draft discarded














                              StackExchange.ready(
                              function ()
                              StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53326353%2fdynamically-import-a-react-component-if-that-file-exists-otherwise-show-a-defau%23new-answer', 'question_page');

                              );

                              Post as a guest















                              Required, but never shown





















































                              Required, but never shown














                              Required, but never shown












                              Required, but never shown







                              Required, but never shown

































                              Required, but never shown














                              Required, but never shown












                              Required, but never shown







                              Required, but never shown







                              這個網誌中的熱門文章

                              How to read a connectionString WITH PROVIDER in .NET Core?

                              In R, how to develop a multiplot heatmap.2 figure showing key labels successfully

                              Museum of Modern and Contemporary Art of Trento and Rovereto