I'm using Google App Engine (Python) along with jQuery for Ajax calls to the server. I have a page where I want to load up a list of strings in Javascript from an Ajax call to the server.
The server method I want to invoke:
class BrowseObjects(webapp.RequestHandler):
def get(self):
ids_to_return = get_ids_to_return()
// TODO: How to return these ids to the invoking ajax call?
self.response.out.write(ids_to_return)
The HTML page where I want to be able to access the returned ids:
var strings_from_server = new Array();
$.ajax({
type: "GET",
url: "/get_ids.html",
success: function(responseText){
// TODO: How to read these IDS in here?
strings_from_server = responseText
},
error: function (xhr, ajaxOptions, thrownError){
alert(xhr.responseText);
}
});
My experience with Ajax is limited-- I've only used them to store data to the server (a-la POST commands) and so I really have no idea how to get data back from the server. Thanks in advance for all help
Edit: My final answer:
I've switched to a full Ajax call (to prevent from cross-domain requests) and also to handle 'error' callbacks. My working client method looks like:
$.ajax({开发者_如何学Python
type: "GET",
dataType: "json",
url: "/get_ids.html",
success: function(reponseText){
strings_from_server = responseText
},
error: function (xhr, ajaxOptions, thrownError){
alert(xhr.responseText);
}
});
Note I specify the dataType as 'json'.
And my final server function, with sahid's answer, looks like:class BrowseObjects(webapp.RequestHandler):
def get(self):
ids_to_return = get_ids_to_return()
# Note: I have to map all my objects as `str` objects
response_json = simplejson.dumps(map(str, ids_to_return))
self.response.out.write(response_json)
Thanks all!
The SDK of Google AppEngine provided by django the lib "simplejson".
from django.utils import simplejson
So your handler maybe it simply:
from django.utils import simplejson
class BrowseObjects(webapp.RequestHandler):
def get(self):
ids_to_return = get_ids_to_return()
response_json = simplejson.dumps (ids_to_return)
self.response.out.write(response_json)
There are a good article about ajax/rpc: http://code.google.com/appengine/articles/rpc.html
It's probably not the cleanest solution, but it will work. Since they are just IDs, it sounds like it's safe to push them directly into a string.
class BrowseObjects(webapp.RequestHandler):
def get(self):
ids_to_return = get_ids_to_return()
response_html = '["'
response_html += ids_to_return.join('","')
# Edit: since my ids are Key objects (not strings)
# I had to use the following instead:
# response_html += '","'.join(map(str, ids_to_return))
response_html += '"]'
self.response.out.write(response_html)
and
var strings_from_server = new Array();
$.getJSON("/get_ids.html", function(responseData){
strings_from_server = responseData;
});
You can check to see if the response was empty incase of an error, and you can use $.each to loop through the results.
I am using jQuerys getJSON feature to automatically parse the response. Since I'm just returning a json list, it will generate the array of data in the strings_from_server
variable.
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