Difference between setCallBack and getCallBack function?












2














Please tell the difference between setCallBack and getCallBack function? Also, If possible can someone please tell me why what is .this function and what does this code is actually doing. (Its related to Instant Notification App https://trailhead.salesforce.com/content/learn/projects/workshop-platform-events/platform-event-subscribe)



const callback = function (message) {
console.log('Event Received : ' + JSON.stringify(message));
helper.onReceiveNotification(component, message);
};

// Subscribe to the channel and save the returned subscription object.

empApi.subscribe(channel, replayId, $A.getCallback(callback)).then($A.getCallback(function (newSubscription) {
console.log('Subscribed to channel ' + channel);
component.set('v.subscription', newSubscription);
}));









share|improve this question





























    2














    Please tell the difference between setCallBack and getCallBack function? Also, If possible can someone please tell me why what is .this function and what does this code is actually doing. (Its related to Instant Notification App https://trailhead.salesforce.com/content/learn/projects/workshop-platform-events/platform-event-subscribe)



    const callback = function (message) {
    console.log('Event Received : ' + JSON.stringify(message));
    helper.onReceiveNotification(component, message);
    };

    // Subscribe to the channel and save the returned subscription object.

    empApi.subscribe(channel, replayId, $A.getCallback(callback)).then($A.getCallback(function (newSubscription) {
    console.log('Subscribed to channel ' + channel);
    component.set('v.subscription', newSubscription);
    }));









    share|improve this question



























      2












      2








      2







      Please tell the difference between setCallBack and getCallBack function? Also, If possible can someone please tell me why what is .this function and what does this code is actually doing. (Its related to Instant Notification App https://trailhead.salesforce.com/content/learn/projects/workshop-platform-events/platform-event-subscribe)



      const callback = function (message) {
      console.log('Event Received : ' + JSON.stringify(message));
      helper.onReceiveNotification(component, message);
      };

      // Subscribe to the channel and save the returned subscription object.

      empApi.subscribe(channel, replayId, $A.getCallback(callback)).then($A.getCallback(function (newSubscription) {
      console.log('Subscribed to channel ' + channel);
      component.set('v.subscription', newSubscription);
      }));









      share|improve this question















      Please tell the difference between setCallBack and getCallBack function? Also, If possible can someone please tell me why what is .this function and what does this code is actually doing. (Its related to Instant Notification App https://trailhead.salesforce.com/content/learn/projects/workshop-platform-events/platform-event-subscribe)



      const callback = function (message) {
      console.log('Event Received : ' + JSON.stringify(message));
      helper.onReceiveNotification(component, message);
      };

      // Subscribe to the channel and save the returned subscription object.

      empApi.subscribe(channel, replayId, $A.getCallback(callback)).then($A.getCallback(function (newSubscription) {
      console.log('Subscribed to channel ' + channel);
      component.set('v.subscription', newSubscription);
      }));






      lightning-aura-components






      share|improve this question















      share|improve this question













      share|improve this question




      share|improve this question








      edited 1 hour ago

























      asked 1 hour ago









      Sukruti

      326




      326






















          1 Answer
          1






          active

          oldest

          votes


















          1














          action.setCallback() is used to provide a callback function when making a call to a server-side Apex controller:



              var action = component.get("c.someMethod");
          action.setParams({ param: cmp.get("v.aParameter") });
          action.setCallback(this, function(response) {
          // Do things.
          }
          $A.enqueueAction(action);


          $A.getCallback() is used when passing a callback function to a function outside the Lightning framework that might interact with a component outside the normal rendering lifecycle, such as setTimeout():



          window.setTimeout(
          $A.getCallback(function() {
          cmp.set("v.visible", true);
          }), 5000
          );


          You do not need to use $A.getCallback() when interacting with Apex server controller methods.



          The code that you posted is using the <lightning:empApi> component to subscribe to a Platform Event. The subscription is handled by a JavaScript library that speaks the CometD protocol and callbacks are performed asynchronously at any time. Hence the use case falls into the realm of $A.getCallback() as described above.






          share|improve this answer























          • Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
            – Sukruti
            1 hour ago










          • If you have specific code, please edit it into your question.
            – David Reed
            1 hour ago










          • Hi David, Please let me know if you can help here.
            – Sukruti
            1 hour ago











          Your Answer








          StackExchange.ready(function() {
          var channelOptions = {
          tags: "".split(" "),
          id: "459"
          };
          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: false,
          noModals: true,
          showLowRepImageUploadWarning: true,
          reputationToPostImages: null,
          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%2fsalesforce.stackexchange.com%2fquestions%2f244602%2fdifference-between-setcallback-and-getcallback-function%23new-answer', 'question_page');
          }
          );

          Post as a guest















          Required, but never shown

























          1 Answer
          1






          active

          oldest

          votes








          1 Answer
          1






          active

          oldest

          votes









          active

          oldest

          votes






          active

          oldest

          votes









          1














          action.setCallback() is used to provide a callback function when making a call to a server-side Apex controller:



              var action = component.get("c.someMethod");
          action.setParams({ param: cmp.get("v.aParameter") });
          action.setCallback(this, function(response) {
          // Do things.
          }
          $A.enqueueAction(action);


          $A.getCallback() is used when passing a callback function to a function outside the Lightning framework that might interact with a component outside the normal rendering lifecycle, such as setTimeout():



          window.setTimeout(
          $A.getCallback(function() {
          cmp.set("v.visible", true);
          }), 5000
          );


          You do not need to use $A.getCallback() when interacting with Apex server controller methods.



          The code that you posted is using the <lightning:empApi> component to subscribe to a Platform Event. The subscription is handled by a JavaScript library that speaks the CometD protocol and callbacks are performed asynchronously at any time. Hence the use case falls into the realm of $A.getCallback() as described above.






          share|improve this answer























          • Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
            – Sukruti
            1 hour ago










          • If you have specific code, please edit it into your question.
            – David Reed
            1 hour ago










          • Hi David, Please let me know if you can help here.
            – Sukruti
            1 hour ago
















          1














          action.setCallback() is used to provide a callback function when making a call to a server-side Apex controller:



              var action = component.get("c.someMethod");
          action.setParams({ param: cmp.get("v.aParameter") });
          action.setCallback(this, function(response) {
          // Do things.
          }
          $A.enqueueAction(action);


          $A.getCallback() is used when passing a callback function to a function outside the Lightning framework that might interact with a component outside the normal rendering lifecycle, such as setTimeout():



          window.setTimeout(
          $A.getCallback(function() {
          cmp.set("v.visible", true);
          }), 5000
          );


          You do not need to use $A.getCallback() when interacting with Apex server controller methods.



          The code that you posted is using the <lightning:empApi> component to subscribe to a Platform Event. The subscription is handled by a JavaScript library that speaks the CometD protocol and callbacks are performed asynchronously at any time. Hence the use case falls into the realm of $A.getCallback() as described above.






          share|improve this answer























          • Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
            – Sukruti
            1 hour ago










          • If you have specific code, please edit it into your question.
            – David Reed
            1 hour ago










          • Hi David, Please let me know if you can help here.
            – Sukruti
            1 hour ago














          1












          1








          1






          action.setCallback() is used to provide a callback function when making a call to a server-side Apex controller:



              var action = component.get("c.someMethod");
          action.setParams({ param: cmp.get("v.aParameter") });
          action.setCallback(this, function(response) {
          // Do things.
          }
          $A.enqueueAction(action);


          $A.getCallback() is used when passing a callback function to a function outside the Lightning framework that might interact with a component outside the normal rendering lifecycle, such as setTimeout():



          window.setTimeout(
          $A.getCallback(function() {
          cmp.set("v.visible", true);
          }), 5000
          );


          You do not need to use $A.getCallback() when interacting with Apex server controller methods.



          The code that you posted is using the <lightning:empApi> component to subscribe to a Platform Event. The subscription is handled by a JavaScript library that speaks the CometD protocol and callbacks are performed asynchronously at any time. Hence the use case falls into the realm of $A.getCallback() as described above.






          share|improve this answer














          action.setCallback() is used to provide a callback function when making a call to a server-side Apex controller:



              var action = component.get("c.someMethod");
          action.setParams({ param: cmp.get("v.aParameter") });
          action.setCallback(this, function(response) {
          // Do things.
          }
          $A.enqueueAction(action);


          $A.getCallback() is used when passing a callback function to a function outside the Lightning framework that might interact with a component outside the normal rendering lifecycle, such as setTimeout():



          window.setTimeout(
          $A.getCallback(function() {
          cmp.set("v.visible", true);
          }), 5000
          );


          You do not need to use $A.getCallback() when interacting with Apex server controller methods.



          The code that you posted is using the <lightning:empApi> component to subscribe to a Platform Event. The subscription is handled by a JavaScript library that speaks the CometD protocol and callbacks are performed asynchronously at any time. Hence the use case falls into the realm of $A.getCallback() as described above.







          share|improve this answer














          share|improve this answer



          share|improve this answer








          edited 59 mins ago

























          answered 1 hour ago









          David Reed

          29.4k61746




          29.4k61746












          • Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
            – Sukruti
            1 hour ago










          • If you have specific code, please edit it into your question.
            – David Reed
            1 hour ago










          • Hi David, Please let me know if you can help here.
            – Sukruti
            1 hour ago


















          • Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
            – Sukruti
            1 hour ago










          • If you have specific code, please edit it into your question.
            – David Reed
            1 hour ago










          • Hi David, Please let me know if you can help here.
            – Sukruti
            1 hour ago
















          Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
          – Sukruti
          1 hour ago




          Thanks David for explanation. So the getCallBack method will execute when we are calling a method that is not part of aura framework. If possible can tell please tell me how below code is working:
          – Sukruti
          1 hour ago












          If you have specific code, please edit it into your question.
          – David Reed
          1 hour ago




          If you have specific code, please edit it into your question.
          – David Reed
          1 hour ago












          Hi David, Please let me know if you can help here.
          – Sukruti
          1 hour ago




          Hi David, Please let me know if you can help here.
          – Sukruti
          1 hour ago


















          draft saved

          draft discarded




















































          Thanks for contributing an answer to Salesforce Stack Exchange!


          • 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.





          Some of your past answers have not been well-received, and you're in danger of being blocked from answering.


          Please pay close attention to the following guidance:


          • 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%2fsalesforce.stackexchange.com%2fquestions%2f244602%2fdifference-between-setcallback-and-getcallback-function%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







          Popular posts from this blog

          Accessing regular linux commands in Huawei's Dopra Linux

          Can't connect RFCOMM socket: Host is down

          Kernel panic - not syncing: Fatal Exception in Interrupt