JavaScript objects with resetting variables -


i'm learning javascript objects , have question/problem. have following code / js object:

changed: complete code - it's appcelerator titanium project!:

spike.xhr = spike.xhr || {};  spike.xhr.init = function() {     this.severresponse = '';     this.xhrmethod = 'get'; }  spike.xhr.isonline = function() {     if( titanium.network.online ) {         return true;     } else {         return false;     } }  spike.xhr.notonline = function() {     var alertdialog = titanium.ui.createalertdialog({          title: config.project_short,          message: 'you not have online connect. please connect...',         buttonnames: ['continue'],         cancel: 0     });      alertdialog.show();  }  spike.xhr.connect = function( url ) {      if( spike.xhr.isonline() ) {         spike.xhr.clients = ti.network.createhttpclient();          spike.xhr.clients.onload = function() {             if (spike.xhr.clients.status != 200 && spike.xhr.clients.status != 201) {                 var alertdialog = titanium.ui.createalertdialog({                      title: config.project_short,                      message: 'we sorry, have received status error!',                     buttonnames: ['continue'],                     cancel: 0                 });                  alertdialog.show();                  return false;             }                 this.serverresponse = this.responsetext;          }          spike.xhr.clients.onerror = function(e) {             ti.api.log( 'error: ' + e.status + ': ' + e.statustext + ' - ' + e.error );         }             spike.xhr.clients.open( this.xhrmethod, url );          spike.xhr.clients.send();     } else {         spike.xhr.notonline();     } }  spike.xhr.basicauthentication = function( username, password ) {     authstr = 'basic ' +titanium.utils.base64encode( username+':'+ password);     spike.xhr.client.setrequestheader( 'authorization', authstr ); }  spike.xhr.setmethod = function( type ) {     this.xhrmethod = type; }  spike.xhr.response = function() {     return this.serverresponse; }

if run:

spike.xhr.connect( 'http://mydomain' ); theresponse = spike.xhr.response();

i <null> returned! - why not "this test!" or better question: have change "this test!" back?

the reason above code doesn't work because spike.xhr.connect function asynchronous. means can tell browser make request, continue doing other stuff while browser waits response come back.

javascript runs in single thread, meaning can execute 1 thing @ time. operations "ajax" calls asynchronous in browser knows how make request, doesn't block running code wait request. typically, asynchronous code called callback function, runs when request returned:

// pseudo code.  spike.xhr.connect( 'http://google.com', function ( response ) {     alert( 'google' ); }); alert( 'this fire before spike.xhr.connects callback' );

the callback function executed when response server comes and browser isn't doing else.


Comments

Post a Comment

Popular posts from this blog

jquery - Invalid Assignment Left-Hand Side -

i trying assign class tag via jquery, resulting in error through firebug says "invalid assignment left-hand side" on fourth line below. <cfoutput> $('.pngfix a').each(function(index) { var hreflink = $(this).attr("href"); if (hreflink.tolowercase() = '../audio.cfm') { $(this).addclass('audioimg'); } }); </cfoutput> looking around online, looks syntax problem, don't seem see it... any tips? thanks if (hreflink.tolowercase() = '../audio.cfm') that attempts assign value, rather check equality. change = operator == .
Read more

java - Play! framework 2.0: How to display multiple image? -

i need display gallery of photos. here template: @(photos: list[photo]) @title = { <bold>gallery</bold> } @main(title,"photo"){ <ul class="thumbnails"> @for(photo <- photos) { <li class="span3"> <a href="#" class="thumbnail"> <img src="@photo.path" alt=""> </a> </li> } </ul> } and here controller method: public static result getphotos() { return ok(views.html.photo.gallery.render(photo.get())); } and here photo bean : @entity public class photo extends model { @id public long id; @required public string label; public string path; public photo(string path, string label) { this.path = path; this.label = label; } private static finder<long, photo> find = new finder<long, photo>( long.class, photo.class); public static list<phot...
Read more

gmail - Is there any documentation for read-only access to the Google Contacts API? -

i want read-only access user's google contacts. there stackoverflow member wanted this, , received following answer : yes, there is, use https://www.googleapis.com/auth/contacts.readonly scope , "view contacts". this exchange reference read-only access google contacts can find using google. simply using access token obtained attempt read usual google contacts api (i.e. https://www.google.com/m8/feeds ) fails insufficient permissions. similarly, using google contacts api on new target fails 404 errors (for example https://www.googleapis.com/auth/contacts.readonly/default/full ). is there documentation anywhere on how use api, or permissible way access google contacts api full read-write access?
Read more