Introduction

Installation

Limitations of the "file" protocol

Frequently asked questions

Syntax, keywords and built-in functions

Standard distribution

import implementation

Brython packages

Browser interface

Brython-specific built-in modules

Working with Brython

Cookbook

module browser.ajax

Methods without a request body

url is the address of the requested resource

blocking is a boolean to specify if the request is blocking or not. The default value is False (asynchronous request)

headers is a dictionary with the HTTP headers key / values

mode is the read mode : "text", "binary", "json", "document"

if mode is "text", encoding is the text file encoding

data is either a string, a dictionary, or an object created by form_data()(see below). In the second case, the dictionary is converted into a string of the form x=1&y=2.

cache is a boolean to specify if the GET request should use the browser cache. It is set to False by default, which means that a random numeric parameter is added to the request

timeout is the time in seconds after which the request is canceled

**callbacks is a dictionary where keys are of the form on + event name (onloaded, oncomplete...) and the value is the callback function that handles this event

Methods with a request body

Callback functions

• "uninitialized" : not initialized
• "loading" : established connection
• "loaded": received request
• "interactive": response in progress
• "complete" : finished

HTTP response code (integer) : 200 if the resource was found, 404 if it doesn't exist, etc.

the response text : instance of str if request mode is "text", "json" or "xml", instance of bytes if mode is "binary"

if request mode is "json", attribute json is the object obtained by parsing the JSON string sent by the server

if request mode is "document", attribute xml is the object containing the XML tree obtained from the response string

reads the response in the format determined by request mode

Examples

from browser import ajax

def read(req):
    print(req.text)

ajax.get("test.txt", oncomplete=read)

from browser import ajax

def read(req):
    print(req.text)

ajax.get("test-latin1.txt", encoding="latin1", oncomplete=read)

from browser import ajax

def read(req):
    assert isinstance(req.text, bytes)

ajax.get("test.txt", mode="binary", oncomplete=read)

from browser import ajax

def read(req):
    assert isinstance(req.read(), bytes)

ajax.get("picture.png", mode="binary", oncomplete=read)

from browser import ajax

def read(req):
    print(req.json)

ajax.get("test.json", mode="json", oncomplete=read)

Standard Web API interface

method is the HTTP method used for the request (usually GET or POST),

url is the resource location,

async is a boolean that indicates whether the call is asynchronous (the script that started the request goes on running without waiting for the response) or not (the script hangs until the response is received).

attaches the function to the event evt. The events are the same as above.

The function takes a single argument, the Ajax instance, with the same attributes as above.

if the resource specified by the url is a text file, encoding is the file encoding

if the Mime type (cf. documentation) is not explicitely set, giving a value to encoding sets the Mime type to "text/plain;charset=x-user-defined".

This makes it possible to set the attribute text to the file content with the specified encoding

the expected response type (cf. documentation)

whether or not cross-site Access-Control requests should be made using credentials such as cookies, authorization headers or TLS client certificates (cf. documentation)

sets the value of the header name.

if the query did not return response within duration in seconds, it will cancel the query and execute the function. This function cannot have arguments.

Form data

Sending the request

sends (starts) the request. The optional argument data is ignored if the method is not POST, PUT or PATCH ; it must be a dictionary, a string or an object created by form_data()

Example

from browser import document, ajax

def on_complete(req):
   if req.status == 200 or req.status == 0:
       document["result"].html = req.text
   else:
       document["result"].html = "error " + req.text

req = ajax.Ajax()
req.bind('complete', on_complete)
# send a POST request to the url
req.open('POST', url, True)
req.set_header('content-type', 'application/x-www-form-urlencoded')
# send data as a dictionary
req.send({'x': 0, 'y': 1})

File upload

<input type="file" name="choosefiles" multiple="multiple">

<input type="file" id="file_upload">
<button id="btn">send</button>

<script type="text/python">
from browser import document, bind, ajax

def complete(ev):
  print('req complete', ev.text)

@bind('#btn', 'click')
def send(ev):
  print(document['file_upload'].files[0])
  req = ajax.Ajax()
  form_data = ajax.form_data()
  form_data.append("upload", document['file_upload'].files[0])
  req.open('POST', '/cgi-bin/file_upload.py')
  req.bind('complete', complete)
  req.send(form_data)

</script>

file is the file object to upload to the url, usually the result of an expression

for file in document["choosefiles"].files:
    ...

method is the method used for the upload call, "POST" by default but can be set to "PUT"

field_name is the name of the field associated with the file to send. It will be used on the server side to get the data

headers and timeout have the same meaning as above

additional data can be added to the request; it must be a dictionary or an object created by form_data()

<script type="text/python">
from browser import ajax, bind, document

def upload_ok(req):
    print("all right")

@bind("#upload", "click")
def uploadfiles(event):
    for f in document["choosefiles"].files:
        ajax.file_upload("/cgi-bin/savefile.py", f,
            oncomplete=upload_ok)
</script>

<form>
    <input id="choosefiles" type="file" multiple="multiple" />
</form>
<button id="upload">Upload</button>