以模板角度 2 显示 JSON 对象

Question

I have this:

stanservice.categoryDetail(this.params.get('id'))
  .then((data) => {
    this.category = JSON.stringify(data.res.rows[0]);
    console.log(JSON.stringify(data.res.rows[0]));
  })
  .catch((error) => {
    console.log("Error message", error.err);
  });

The console log returns this:

{"id":6,"name":"destiny","note":"nice","type":"income"}

Then I am able to display this.category in my template as this:

{{ category }}

which returns this

{"id":6,"name":"destiny","note":"nice","type":"income"}

However, when I try to display the values of the object by doing this

{{ category.name }}

I get this error:

EXCEPTION: Error: Uncaught (in promise): EXCEPTION: TypeError: Cannot read property 'name' of undefined in [
            {{ category.name }}
         in CategorydetailPage@16:18]
ORIGINAL EXCEPTION: TypeError: Cannot read property 'name' of undefined
ORIGINAL STACKTRACE:
TypeError: Cannot read property 'name' of undefined
    at AbstractChangeDetector.ChangeDetector_CategorydetailPage_0.detectChangesInRecordsInternal (viewFactory_CategorydetailPage:67:28)
    at AbstractChangeDetector.detectChangesInRecords (http://localhost:8100/build/js/app.bundle.js:13535:18)
    at AbstractChangeDetector.runDetectChanges (http://localhost:8100/build/js/app.bundle.js:13512:14)
    at AbstractChangeDetector._detectChangesInViewChildren (http://localhost:8100/build/js/app.bundle.js:13612:18)
    at AbstractChangeDetector.runDetectChanges (http://localhost:8100/build/js/app.bundle.js:13516:14)
    at AbstractChangeDetector.detectChanges (http://localhost:8100/build/js/app.bundle.js:13501:73)
    at ChangeDetectorRef_.detectChanges (http://localhost:8100/build/js/app.bundle.js:14402:73)
    at ViewController.willEnter (http://localhost:8100/build/js/app.bundle.js:46071:22)
    at NavController._postRender (http://localhost:8100/build/js/app.bundle.js:44385:30)
    at http://localhost:8100/build/js/app.bundle.js:44333:27
ERROR CONTEXT:
[object Object]

Answer 1

Don't use the this keyword within the then function. And don't stringify your JavaScript object. Instead of:

stanservice.categoryDetail(this.params.get('id'))
   .then((data) => {
       this.category = JSON.stringify(data.res.rows[0]);
       console.log(JSON.stringify(data.res.rows[0]));
})
.catch((error) => {
   console.log("Error message", error.err);
});

Try:

var app = this;

stanservice.categoryDetail(this.params.get('id'))
   .then((data) => {
      app.category = data.res.rows[0];
      console.log(data.res.rows[0]);
})
.catch((error) => {
   console.log("Error message", error.err);
});