Making synchronous call in Angular 2 with Firebase -


i have service needs upload image firebase storage first , return downloadurl. after getting download url need store firebase realtime database.

but problem here firebase calls asynchronous.

this code :

 addcategory(category){  let storageref = firebase.storage().ref(`category/${category.img_name}`);     //upload file      storageref.put(category.url)       .then((snapshot) => {     // here download url         var downloadurl = snapshot.downloadurl;         category.category_icon = downloadurl.tostring();        })       //problem occurs here return executed before .then statement , download url becomes undefined.          return this.http.post('https://app_name.cloudfunctions.net/api/products',body,{headers:headers})         .map(res =>res.json());   }

so need know there possibility stop making call (storageref.put()) synchronous return statement should trigger after completion of .put() call.

thanks in advance!!

when want wait while execution completed should return url first "then" second "then" execute after first "then" finished 

addcategory(category){    let storageref = firebase.storage().ref(`category/${category.img_name}`);         //upload file         return storageref.put(category.url)               .then((snapshot) => {                 return snapshot.downloadurl               }).then(url => { // excute after url                   category.category_icon = url.tostring();                   return this.http.post('https://app_name.cloudfunctions.net/api/products',body,{headers:headers})                  .map(res =>res.json());                     }) }

you call addcategory this

addcategory(category).then(obs => {  obs.subscribe(res => {  // add code here })     })

Comments

Post a Comment

Popular posts from this blog

python Tkinter Capturing keyboard events save as one single string -

is possible store keyboard events 1 string? code below stores 1 char , prints it. card reader or bar code reader, contains collection of character/ string not 1 character @ time. goal save char pressed text variable. from tkinter import * root = tk() def key(event): text= event.char text+= event.char print ("pressed", text) def callback(event): frame.focus_set() print ("clicked at", event.x, event.y) frame = frame(root, width=100, height=100) frame.bind("<key>", key) frame.bind("<button-1>", callback) frame.pack() root.mainloop() currently, creating text variable , everytime key() function gets called, , text stores last character typed. you can define text module level variable , , use module level text inside key function - text = '' def key(event): global text text+= event.char print("pressed", text)
Read more

android - InAppBilling registering BroadcastReceiver in AndroidManifest -

i'm implementing inapp billing in android app. works well, however, i'm trying decouple broadcast receiver activity manifest. suggestion in android's trivialdrive sample: // important: dynamically register broadcast messages updated purchases. // register receiver here instead of <receiver> in manifest // because call getpurchases() @ startup, therefore can ignore // broadcasts sent while app isn't running. // note: registering listener in activity bad idea, done here // because sample. regardless, receiver must registered after // iabhelper setup, before first call getpurchases(). currently there's class extends broadcastreceiver : public class iabbroadcastreceiver extends broadcastreceiver { /** * intent action receiver should filter for. */ public static final string action = "com.android.vending.billing.purchases_updated"; private final iabbroadcastlistener mlistener; public iabbroadcastreceiver(iabbroadcastlistener listener) { m
Read more

javascript - Z-index in d3.js -

i have map , when hover effect on region of map below yellow line , circle, last ones disappear. how can solve problem? http://jsfiddle.net/ot21n9qx/ var arc = g.append("path") .style("fill", "none") .style("stroke", "yellow") .style("stroke-width", 2) .attr("d", "m" + pathorigin[0] + "," + pathorigin[1] + " q" + svgpoint[0] + "," + pathorigin[1] + " " + svgpoint[0] + "," + svgpoint[1]); var circlesize = d3.scale.linear() .domain([0, 0.5, 1]) .range([4, 10, 4]); svg not have z order draws objects in order created. need create path , circle after create highlight regions. here forked fiddle: http://jsfiddle.net/o00fzgaf/1/
Read more