angular - Typescript promise losing values after .then -

i have function within angular2 service returning mock data via promise.resolve when unwrapped .then gives me empty promise object. can see calling function receiving promise payload in __zone_symbole__value property before passed .then inside of.theni seem left empty promise.

  gettemperaturedata(): promise<any> {      let data = this.convertjsontogooglecharttable(temperaturedata_json);     let p = promise.resolve(data);     return p;   } 

using chrome see p above looks like

zoneawarepromise {__zone_symbol__state: true, __zone_symbol__value: "[["date","temperature","lowtemperature"],["05/11/2…",69.02,null],["06/11/2016 23:54:34",69.99,null]]"}

the calling code broken 2 lines debug below.

gettemperaturedata() {     var d = this.dataservice.gettemperaturedata();     d.then(data => this.line_chartdata = data); } 

when @ d see same p above

zoneawarepromise {__zone_symbol__state: true, __zone_symbol__value: "[["date","temperature","lowtemperature"],["05/11/2…",69.02,null],["06/11/2016 23:54:34",69.99,null]]"}

the problem occurs .then value of "d" empty promise. below taken chrome dev tools console show seeing.

d.then(data => console.log(data)) zoneawarepromise {__zone_symbol__state: null, __zone_symbol__value: array[0]} 

no matter , how many combinations have tried cannot data inside of d. (note p , d temporary break code down now.)

my package.json below:

{   "name": "angular2",   "version": "0.0.0",   "license": "mit",    "angular-cli": {},   "scripts": {     "start": "ng serve",     "lint": "tslint \"src/**/*.ts\"",     "test": "ng test",     "pree2e": "webdriver-manager update",     "e2e": "protractor"   },   "private": true,   "dependencies": {     "@angular/common": "~2.1.0",     "@angular/compiler": "~2.1.0",     "@angular/core": "~2.1.0",     "@angular/forms": "~2.1.0",     "@angular/http": "~2.1.0",     "@angular/material": "^2.0.0-alpha.9-3",     "@angular/platform-browser": "~2.1.0",     "@angular/platform-browser-dynamic": "~2.1.0",     "@angular/router": "~3.1.0",     "core-js": "^2.4.1",     "ng2-bootstrap": "^1.1.16",     "node-mysql": "^0.4.2",     "rxjs": "5.0.0-beta.12",     "ts-helpers": "^1.1.1",     "zone.js": "^0.6.23"   },   "devdependencies": {     "@types/jasmine": "^2.2.30",     "@types/node": "^6.0.42",     "angular-cli": "1.0.0-beta.19-3",     "codelyzer": "1.0.0-beta.1",     "jasmine-core": "2.4.1",     "jasmine-spec-reporter": "2.5.0",     "karma": "1.2.0",     "karma-chrome-launcher": "^2.0.0",     "karma-cli": "^1.0.1",     "karma-jasmine": "^1.0.2",     "karma-remap-istanbul": "^0.2.1",     "protractor": "4.0.9",     "ts-node": "1.2.1",     "tslint": "3.13.0",     "typescript": "~2.0.3",     "webdriver-manager": "10.2.5"   } } 

the value of data empty promise

that tells me convertjsontogooglecharttable returning promise, , you're not chaining promise it.

note if using stronger type any, typescript compiler have caught you.

since you're not doing after getting data, this:

  gettemperaturedata(): promise<any> {     return this.convertjsontogooglecharttable(temperaturedata_json);   } 

but if want data before returning it, can in then, chained off of original promise:

  gettemperaturedata(): promise<any> {     return this.convertjsontogooglecharttable(temperaturedata_json)         .then(data => {             console.log(data);             return data;         });   }