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<h2><span class="refentrytitle">libsoup Client Basics</span></h2>
<p>libsoup Client Basics — Client-side tutorial</p>
</td>
<td class="gallery_image" valign="top" align="right"></td>
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<div class="refsect2">
<a name="id-1.2.3.3"></a><p>
This section explains how to use <span class="application">libsoup</span> as
an HTTP client using several new APIs introduced in version 2.42. If
you want to be compatible with older versions of
<span class="application">libsoup</span>, consult the documentation for that
version.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.4"></a><h3>Creating a <span class="type">SoupSession</span>
</h3>
<p>
The first step in using the client API is to create a <a class="link" href="SoupSession.html" title="SoupSession"><span class="type">SoupSession</span></a>. The session object
encapsulates all of the state that <span class="application">libsoup</span>
is keeping on behalf of your program; cached HTTP connections,
authentication information, etc.
</p>
<p>
When you create the session with <a class="link" href="SoupSession.html#soup-session-new-with-options" title="soup_session_new_with_options ()"><code class="function">soup_session_new_with_options</code></a>,
you can specify various additional options:
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-MAX-CONNS:CAPS" title="SOUP_SESSION_MAX_CONNS"><code class="literal">SOUP_SESSION_MAX_CONNS</code></a></span></p></td>
<td><p>
Allows you to set the maximum total number of connections
the session will have open at one time. (Once it reaches
this limit, it will either close idle connections, or
wait for existing connections to free up before starting
new requests.) The default value is 10.
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-MAX-CONNS-PER-HOST:CAPS" title="SOUP_SESSION_MAX_CONNS_PER_HOST"><code class="literal">SOUP_SESSION_MAX_CONNS_PER_HOST</code></a></span></p></td>
<td><p>
Allows you to set the maximum total number of connections
the session will have open <span class="emphasis"><em>to a single
host</em></span> at one time. The default value is 2.
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-USER-AGENT:CAPS" title="SOUP_SESSION_USER_AGENT"><code class="literal">SOUP_SESSION_USER_AGENT</code></a></span></p></td>
<td><p>
Allows you to set a User-Agent string that will be sent
on all outgoing requests.
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-ACCEPT-LANGUAGE:CAPS" title="SOUP_SESSION_ACCEPT_LANGUAGE"><code class="literal">SOUP_SESSION_ACCEPT_LANGUAGE</code></a>
and <a class="link" href="SoupSession.html#SOUP-SESSION-ACCEPT-LANGUAGE-AUTO:CAPS" title="SOUP_SESSION_ACCEPT_LANGUAGE_AUTO"><code class="literal">SOUP_SESSION_ACCEPT_LANGUAGE_AUTO</code></a></span></p></td>
<td><p>
Allow you to set an Accept-Language header on all outgoing
requests. <code class="literal">SOUP_SESSION_ACCEPT_LANGUAGE</code>
takes a list of language tags to use, while
<code class="literal">SOUP_SESSION_ACCEPT_LANGUAGE_AUTO</code>
automatically generates the list from the user's locale
settings.
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-HTTP-ALIASES:CAPS" title="SOUP_SESSION_HTTP_ALIASES"><code class="literal">SOUP_SESSION_HTTP_ALIASES</code></a>
and <a class="link" href="SoupSession.html#SOUP-SESSION-HTTPS-ALIASES:CAPS" title="SOUP_SESSION_HTTPS_ALIASES"><code class="literal">SOUP_SESSION_HTTPS_ALIASES</code></a></span></p></td>
<td><p>
Allow you to tell the session to recognize additional URI
schemes as aliases for "<code class="literal">http</code>" or
<code class="literal">https</code>. You can set this if you are
using URIs with schemes like "<code class="literal">dav</code>" or
"<code class="literal">webcal</code>" (and in particular, you need
to set this if the server you are talking to might return
redirects with such a scheme).
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-PROXY-RESOLVER:CAPS" title="SOUP_SESSION_PROXY_RESOLVER"><code class="literal">SOUP_SESSION_PROXY_RESOLVER</code></a> and <a class="link" href="SoupSession.html#SOUP-SESSION-PROXY-URI:CAPS" title="SOUP_SESSION_PROXY_URI"><code class="literal">SOUP_SESSION_PROXY_URI</code></a></span></p></td>
<td>
<p>
<a class="link" href="SoupSession.html#SOUP-SESSION-PROXY-RESOLVER:CAPS" title="SOUP_SESSION_PROXY_RESOLVER"><code class="literal">SOUP_SESSION_PROXY_RESOLVER</code></a>
specifies a <a href="../gio/GProxyResolver.html#GProxyResolver-struct"><span class="type">GProxyResolver</span></a>
to use to determine the HTTP proxies to use. By default,
this is set to the resolver returned by <a href="../gio/GProxyResolver.html#g-proxy-resolver-get-default"><code class="function">g_proxy_resolver_get_default</code></a>,
so you do not need to set it yourself.
</p>
<p>
Alternatively, if you want all requests to go through a
single proxy, you can set <a class="link" href="SoupSession.html#SOUP-SESSION-PROXY-URI:CAPS" title="SOUP_SESSION_PROXY_URI"><code class="literal">SOUP_SESSION_PROXY_URI</code></a>.
</p>
</td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupSession.html#SOUP-SESSION-ADD-FEATURE:CAPS" title="SOUP_SESSION_ADD_FEATURE"><code class="literal">SOUP_SESSION_ADD_FEATURE</code></a> and <a class="link" href="SoupSession.html#SOUP-SESSION-ADD-FEATURE-BY-TYPE:CAPS" title="SOUP_SESSION_ADD_FEATURE_BY_TYPE"><code class="literal">SOUP_SESSION_ADD_FEATURE_BY_TYPE</code></a></span></p></td>
<td><p>
These allow you to specify <a class="link" href="SoupSessionFeature.html" title="SoupSessionFeature"><span class="type">SoupSessionFeature</span></a>s
(discussed <a class="link" href="libsoup-client-howto.html#session-features" title="Session features">below</a>)
to add at construct-time.
</p></td>
</tr>
</tbody>
</table></div>
<p>
Other properties are also available; see the <a class="link" href="SoupSession.html" title="SoupSession"><span class="type">SoupSession</span></a> documentation for
more details.
</p>
<p>
If you don't need to specify any options, you can just use <a class="link" href="SoupSession.html#soup-session-new" title="soup_session_new ()"><code class="function">soup_session_new</code></a>,
which takes no arguments.
</p>
</div>
<hr>
<div class="refsect2">
<a name="session-features"></a><h3>Session features</h3>
<p>
Additional session functionality is provided as <a class="link" href="SoupSessionFeature.html" title="SoupSessionFeature"><span class="type">SoupSessionFeature</span></a>s,
which can be added to a session, via the <a class="link" href="SoupSession.html#SOUP-SESSION-ADD-FEATURE:CAPS" title="SOUP_SESSION_ADD_FEATURE"><code class="literal">SOUP_SESSION_ADD_FEATURE</code></a>
and <a class="link" href="SoupSession.html#SOUP-SESSION-ADD-FEATURE-BY-TYPE:CAPS" title="SOUP_SESSION_ADD_FEATURE_BY_TYPE"><code class="literal">SOUP_SESSION_ADD_FEATURE_BY_TYPE</code></a>
options at session-construction-time, or afterward via the <a class="link" href="SoupSession.html#soup-session-add-feature" title="soup_session_add_feature ()"><code class="function">soup_session_add_feature</code></a>
and <a class="link" href="SoupSession.html#soup-session-add-feature-by-type" title="soup_session_add_feature_by_type ()"><code class="function">soup_session_add_feature_by_type</code></a>
functions.
</p>
<p>
A <a class="link" href="SoupContentDecoder.html" title="SoupContentDecoder"><span class="type">SoupContentDecoder</span></a> is
added for you automatically. This advertises to servers that the
client supports compression, and automatically decompresses compressed
responses.
</p>
<p>
Some other available features that you can add include:
</p>
<div class="variablelist"><table border="0" class="variablelist">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term"><a class="link" href="SoupLogger.html" title="SoupLogger"><span class="type">SoupLogger</span></a></span></p></td>
<td><p>
A debugging aid, which logs all of libsoup's HTTP traffic
to <code class="literal">stdout</code> (or another place you specify).
</p></td>
</tr>
<tr>
<td><p><span class="term">
<a class="link" href="SoupCookieJar.html" title="SoupCookieJar"><span class="type">SoupCookieJar</span></a>,
<a class="link" href="SoupCookieJarText.html" title="SoupCookieJarText"><span class="type">SoupCookieJarText</span></a>,
and <a class="link" href="SoupCookieJarDB.html" title="SoupCookieJarDB"><span class="type">SoupCookieJarDB</span></a>
</span></p></td>
<td><p>
Support for HTTP cookies. <span class="type">SoupCookieJar</span>
provides non-persistent cookie storage, while
<span class="type">SoupCookieJarText</span> uses a text file to keep
track of cookies between sessions, and
<span class="type">SoupCookieJarDB</span> uses a
<span class="application">SQLite</span> database.
</p></td>
</tr>
<tr>
<td><p><span class="term"><a class="link" href="SoupContentSniffer.html" title="SoupContentSniffer"><span class="type">SoupContentSniffer</span></a></span></p></td>
<td><p>
Uses the HTML5 sniffing rules to attempt to
determine the Content-Type of a response when the
server does not identify the Content-Type, or appears to
have provided an incorrect one.
</p></td>
</tr>
</tbody>
</table></div>
<p>
Use the "add_feature_by_type" property/function to add features that
don't require any configuration (such as <a class="link" href="SoupContentSniffer.html" title="SoupContentSniffer"><span class="type">SoupContentSniffer</span></a>),
and the "add_feature" property/function to add features that must be
constructed first (such as <a class="link" href="SoupLogger.html" title="SoupLogger"><span class="type">SoupLogger</span></a>). For example, an
application might do something like the following:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11</pre></td>
<td class="listing_code"><pre class="programlisting">session <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupSession.html#soup-session-new-with-options">soup_session_new_with_options</a></span> <span class="gtkdoc opt">(</span>
SOUP_SESSION_ADD_FEATURE_BY_TYPE<span class="gtkdoc opt">,</span> SOUP_TYPE_CONTENT_SNIFFER<span class="gtkdoc opt">,</span>
NULL<span class="gtkdoc opt">);</span>
<span class="keyword">if</span> <span class="gtkdoc opt">(</span>debug_level<span class="gtkdoc opt">) {</span>
SoupLogger <span class="gtkdoc opt">*</span>logger<span class="gtkdoc opt">;</span>
logger <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupLogger.html#soup-logger-new">soup_logger_new</a></span> <span class="gtkdoc opt">(</span>debug_level<span class="gtkdoc opt">, -</span><span class="number">1</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="SoupSession.html#soup-session-add-feature">soup_session_add_feature</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> <span class="function">SOUP_SESSION_FEATURE</span> <span class="gtkdoc opt">(</span>logger<span class="gtkdoc opt">));</span>
<span class="function"><a href="../gobject/gobject-The-Base-Object-Type.html#g-object-unref">g_object_unref</a></span> <span class="gtkdoc opt">(</span>logger<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.6"></a><h3>Creating and Sending SoupMessages</h3>
<p>
Once you have a session, you send HTTP requests using <a class="link" href="SoupMessage.html" title="SoupMessage"><span class="type">SoupMessage</span></a>. In the simplest
case, you only need to create the message and it's ready to send:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3</pre></td>
<td class="listing_code"><pre class="programlisting">SoupMessage <span class="gtkdoc opt">*</span>msg<span class="gtkdoc opt">;</span>
msg <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupMessage.html#soup-message-new">soup_message_new</a></span> <span class="gtkdoc opt">(</span><span class="string">"GET"</span><span class="gtkdoc opt">,</span> <span class="string">"http://example.com/"</span><span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
In more complicated cases, you can use various <a class="link" href="SoupMessage.html" title="SoupMessage">SoupMessage</a>, <a class="link" href="SoupMessageHeaders.html" title="SoupMessageHeaders">SoupMessageHeaders</a>, and <a class="link" href="SoupMessageBody.html" title="SoupMessageBody">SoupMessageBody</a> methods to set the
request headers and body of the message:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6</pre></td>
<td class="listing_code"><pre class="programlisting">SoupMessage <span class="gtkdoc opt">*</span>msg<span class="gtkdoc opt">;</span>
msg <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupMessage.html#soup-message-new">soup_message_new</a></span> <span class="gtkdoc opt">(</span><span class="string">"POST"</span><span class="gtkdoc opt">,</span> <span class="string">"http://example.com/form.cgi"</span><span class="gtkdoc opt">);</span>
<span class="function"><a href="SoupMessage.html#soup-message-set-request">soup_message_set_request</a></span> <span class="gtkdoc opt">(</span>msg<span class="gtkdoc opt">,</span> <span class="string">"application/x-www-form-urlencoded"</span><span class="gtkdoc opt">,</span>
SOUP_MEMORY_COPY<span class="gtkdoc opt">,</span> formdata<span class="gtkdoc opt">,</span> <span class="function">strlen</span> <span class="gtkdoc opt">(</span>formdata<span class="gtkdoc opt">));</span>
<span class="function"><a href="SoupMessageHeaders.html#soup-message-headers-append">soup_message_headers_append</a></span> <span class="gtkdoc opt">(</span>msg<span class="gtkdoc opt">-></span>request_headers<span class="gtkdoc opt">,</span> <span class="string">"Referer"</span><span class="gtkdoc opt">,</span> referring_url<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
(Although this is a bad example, because
<span class="application">libsoup</span> actually has convenience methods
for dealing with <a class="link" href="libsoup-2.4-HTML-Form-Support.html" title="HTML Form Support">HTML
forms</a>, as well as <a class="link" href="libsoup-2.4-XMLRPC-Support.html" title="XMLRPC Support">XML-RPC</a>.)
</p>
<p>
You can also use <a class="link" href="SoupMessage.html#soup-message-set-flags" title="soup_message_set_flags ()"><code class="function">soup_message_set_flags</code></a>
to change some default behaviors. For example, by default,
<span class="type">SoupSession</span> automatically handles responses from the
server that redirect to another URL. If you would like to handle these
yourself, you can set the <a class="link" href="SoupMessage.html#SOUP-MESSAGE-NO-REDIRECT:CAPS"><code class="literal">SOUP_MESSAGE_NO_REDIRECT</code></a>
flag.
</p>
<div class="refsect3">
<a name="id-1.2.3.6.8"></a><h4>Sending a Message Synchronously</h4>
<p>
To send a message and wait for the response, use <a class="link" href="SoupSession.html#soup-session-send" title="soup_session_send ()"><code class="function">soup_session_send</code></a>:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4</pre></td>
<td class="listing_code"><pre class="programlisting">GInputStream <span class="gtkdoc opt">*</span>stream<span class="gtkdoc opt">;</span>
GError <span class="gtkdoc opt">*</span>error <span class="gtkdoc opt">=</span> NULL<span class="gtkdoc opt">;</span>
stream <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupSession.html#soup-session-send">soup_session_send</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> msg<span class="gtkdoc opt">,</span> cancellable<span class="gtkdoc opt">, &</span>error<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
At the point when <code class="function">soup_session_send</code> returns, the
request will have been sent, and the response headers read back in;
you can examine the message's <em class="structfield"><code>status_code</code></em>,
<em class="structfield"><code>reason_phrase</code></em>, and
<em class="structfield"><code>response_headers</code></em> fields to see the response
metadata. To get the response body, read from the returned <a href="../gio/GInputStream.html#GInputStream-struct"><span class="type">GInputStream</span></a>, and close it
when you are done.
</p>
<p>
Note that <code class="function">soup_session_send</code> only returns an error
if a transport-level problem occurs (eg, it could not connect to the
host, or the request was cancelled). Use the message's
<em class="structfield"><code>status_code</code></em> field to determine whether the
request was successful or not at the HTTP level (ie, "<code class="literal">200
OK</code>" vs "<code class="literal">401 Bad Request</code>").
</p>
<p>
If you would prefer to have <span class="application">libsoup</span> gather
the response body for you and then return it all at once, you can use
the older
<a class="link" href="SoupSession.html#soup-session-send-message" title="soup_session_send_message ()"><code class="function">soup_session_send_message</code></a>
API:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3</pre></td>
<td class="listing_code"><pre class="programlisting">guint status<span class="gtkdoc opt">;</span>
status <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupSession.html#soup-session-send-message">soup_session_send_message</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> msg<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
In this case, the response body will be available in the message's
<em class="structfield"><code>response_body</code></em> field, and transport-level
errors will be indicated in the <em class="structfield"><code>status_code</code></em>
field via special pseudo-HTTP-status codes like <a class="link" href="libsoup-2.4-soup-status.html#SOUP-STATUS-CANT-CONNECT:CAPS"><code class="literal">SOUP_STATUS_CANT_CONNECT</code></a>.
</p>
</div>
<div class="refsect3">
<a name="id-1.2.3.6.9"></a><h4>Sending a Message Asynchronously</h4>
<p>
To send a message asynchronously, use <a class="link" href="SoupSession.html#soup-session-send-async" title="soup_session_send_async ()"><code class="function">soup_session_send_async</code></a>:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11
12
13
14
15</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc opt">{</span>
<span class="gtkdoc opt">...</span>
<span class="function"><a href="SoupSession.html#soup-session-send-async">soup_session_send_async</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> msg<span class="gtkdoc opt">,</span> cancellable<span class="gtkdoc opt">,</span> my_callback<span class="gtkdoc opt">,</span> my_callback_data<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">my_callback</span> <span class="gtkdoc opt">(</span>GObject <span class="gtkdoc opt">*</span>object<span class="gtkdoc opt">,</span> GAsyncResult <span class="gtkdoc opt">*</span>result<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
GInputStream <span class="gtkdoc opt">*</span>stream<span class="gtkdoc opt">;</span>
GError <span class="gtkdoc opt">*</span>error <span class="gtkdoc opt">=</span> NULL<span class="gtkdoc opt">;</span>
stream <span class="gtkdoc opt">=</span> <span class="function"><a href="SoupSession.html#soup-session-send-finish">soup_session_send_finish</a></span> <span class="gtkdoc opt">(</span><span class="function">SOUP_SESSION</span> <span class="gtkdoc opt">(</span>object<span class="gtkdoc opt">),</span> result<span class="gtkdoc opt">, &</span>error<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
The message will be added to the session's queue, and eventually (when
control is returned back to the main loop), it will be sent and the
response be will be read. When the message has been sent, and its
headers received, the callback will be invoked, in the standard
<a href="../gio/GAsyncResult.html#GAsyncReadyCallback"><span class="type">GAsyncReadyCallback</span></a>
style.
</p>
<p>
As with synchronous sending, there is also an alternate API, <a class="link" href="SoupSession.html#soup-session-queue-message" title="soup_session_queue_message ()"><code class="function">soup_session_queue_message</code></a>,
in which your callback is not invoked until the response has been
completely read:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1
2
3
4
5
6
7
8
9
10
11</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="gtkdoc opt">{</span>
<span class="gtkdoc opt">...</span>
<span class="function"><a href="SoupSession.html#soup-session-queue-message">soup_session_queue_message</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> msg<span class="gtkdoc opt">,</span> my_callback<span class="gtkdoc opt">,</span> my_callback_data<span class="gtkdoc opt">);</span>
<span class="gtkdoc opt">...</span>
<span class="gtkdoc opt">}</span>
<span class="gtkdoc kwb">static void</span>
<span class="function">my_callback</span> <span class="gtkdoc opt">(</span>SoupSession <span class="gtkdoc opt">*</span>session<span class="gtkdoc opt">,</span> SoupMessage <span class="gtkdoc opt">*</span>msg<span class="gtkdoc opt">,</span> gpointer user_data<span class="gtkdoc opt">)</span>
<span class="gtkdoc opt">{</span>
<span class="comment">/* msg->response_body contains the response */</span>
<span class="gtkdoc opt">}</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
<a class="link" href="SoupSession.html#soup-session-queue-message" title="soup_session_queue_message ()"><code class="function">soup_session_queue_message</code></a>
is slightly unusual in that it steals a reference to the message
object, and unrefs it after the last callback is invoked on it. So
when using this API, you should not unref the message yourself.
</p>
</div>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.7"></a><h3>Processing the Response</h3>
<p>
Once you have received the initial response from the server,
synchronously or asynchronously, streaming or not, you can look at the
response fields in the <code class="literal">SoupMessage</code> to decide what
to do next. The <em class="structfield"><code>status_code</code></em> and
<em class="structfield"><code>reason_phrase</code></em> fields contain the numeric
status and textual status response from the server.
<em class="structfield"><code>response_headers</code></em> contains the response
headers, which you can investigate using <code class="function">soup_message_headers_get</code>
and <a class="link" href="SoupMessageHeaders.html#soup-message-headers-foreach" title="soup_message_headers_foreach ()"><code class="function">soup_message_headers_foreach</code></a>.
</p>
<p>
<a class="link" href="SoupMessageHeaders.html" title="SoupMessageHeaders"><span class="type">SoupMessageHeaders</span></a>
automatically parses several important headers in
<em class="structfield"><code>response_headers</code></em> for you and provides
specialized accessors for them. Eg, <a class="link" href="SoupMessageHeaders.html#soup-message-headers-get-content-type" title="soup_message_headers_get_content_type ()"><code class="function">soup_message_headers_get_content_type</code></a>.
There are several generic methods such as <a class="link" href="libsoup-2.4-Soup-Miscellaneous-Utilities.html#soup-header-parse-param-list" title="soup_header_parse_param_list ()"><code class="function">soup_header_parse_param_list</code></a>
(for parsing an attribute-list-type header) and <a class="link" href="libsoup-2.4-Soup-Miscellaneous-Utilities.html#soup-header-contains" title="soup_header_contains ()"><code class="function">soup_header_contains</code></a>
(for quickly testing if a list-type header contains a particular
token). These handle the various syntactical oddities of parsing HTTP
headers much better than functions like
<code class="function">g_strsplit</code> or <code class="function">strstr</code>.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.8"></a><h3>Handling Authentication</h3>
<p>
<span class="type">SoupSession</span> handles most of the details of HTTP
authentication for you. If it receives a 401 ("Unauthorized") or 407
("Proxy Authentication Required") response, the session will emit the
<a class="link" href="SoupSession.html#SoupSession-authenticate" title="The “authenticate” signal">authenticate</a> signal,
providing you with a <a class="link" href="SoupAuth.html" title="SoupAuth"><span class="type">SoupAuth</span></a> object indicating the
authentication type ("Basic", "Digest", or "NTLM") and the realm name
provided by the server. If you have a username and password available
(or can generate one), call <a class="link" href="SoupAuth.html#soup-auth-authenticate" title="soup_auth_authenticate ()"><code class="function">soup_auth_authenticate</code></a>
to give the information to libsoup. The session will automatically
requeue the message and try it again with that authentication
information. (If you don't call
<code class="function">soup_auth_authenticate</code>, the session will just
return the message to the application with its 401 or 407 status.)
</p>
<p>
If the server doesn't accept the username and password provided, the
session will emit <a class="link" href="SoupSession.html#SoupSession-authenticate" title="The “authenticate” signal">authenticate</a> again, with the
<code class="literal">retrying</code> parameter set to <code class="literal">TRUE</code>. This lets the
application know that the information it provided earlier was
incorrect, and gives it a chance to try again. If this
username/password pair also doesn't work, the session will contine to
emit <code class="literal">authenticate</code> again and again until the
provided username/password successfully authenticates, or until the
signal handler fails to call <a class="link" href="SoupAuth.html#soup-auth-authenticate" title="soup_auth_authenticate ()"><code class="function">soup_auth_authenticate</code></a>,
at which point <span class="application">libsoup</span> will allow the
message to fail (with status 401 or 407).
</p>
<p>
If you need to handle authentication asynchronously (eg, to pop up a
password dialog without recursively entering the main loop), you can
do that as well. Just call <a class="link" href="SoupSession.html#soup-session-pause-message" title="soup_session_pause_message ()"><code class="function">soup_session_pause_message</code></a>
on the message before returning from the signal handler, and
<code class="function">g_object_ref</code> the <span class="type">SoupAuth</span>. Then,
later on, after calling <code class="function">soup_auth_authenticate</code>
(or deciding not to), call <a class="link" href="SoupSession.html#soup-session-unpause-message" title="soup_session_unpause_message ()"><code class="function">soup_session_unpause_message</code></a>
to resume the paused message.
</p>
<p>
By default, NTLM authentication is not enabled. To add NTLM support to
a session, call:
</p>
<div class="informalexample">
<table class="listing_frame" border="0" cellpadding="0" cellspacing="0">
<tbody>
<tr>
<td class="listing_lines" align="right"><pre>1</pre></td>
<td class="listing_code"><pre class="programlisting"><span class="function"><a href="SoupSession.html#soup-session-add-feature-by-type">soup_session_add_feature_by_type</a></span> <span class="gtkdoc opt">(</span>session<span class="gtkdoc opt">,</span> SOUP_TYPE_AUTH_NTLM<span class="gtkdoc opt">);</span></pre></td>
</tr>
</tbody>
</table>
</div>
<p>
(You can also disable Basic or Digest authentication by calling <a class="link" href="SoupSession.html#soup-session-remove-feature-by-type" title="soup_session_remove_feature_by_type ()"><code class="function">soup_session_remove_feature_by_type</code></a>
on <a class="link" href="SoupAuth.html#SOUP-TYPE-AUTH-BASIC:CAPS" title="SOUP_TYPE_AUTH_BASIC"><code class="literal">SOUP_TYPE_AUTH_BASIC</code></a>
or <a class="link" href="SoupAuth.html#SOUP-TYPE-AUTH-DIGEST:CAPS" title="SOUP_TYPE_AUTH_DIGEST"><code class="literal">SOUP_TYPE_AUTH_DIGEST</code></a>.)
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.9"></a><h3>Multi-threaded usage</h3>
<p>
A <a class="link" href="SoupSession.html" title="SoupSession"><span class="type">SoupSession</span></a> can be
used from multiple threads. However, if you are using the async APIs,
then each thread you use the session from must have its own
thread-default <a href="../glib/glib-The-Main-Event-Loop.html#GMainContext"><span class="type">GMainContext</span></a>.
</p>
<p>
<a class="link" href="SoupMessage.html" title="SoupMessage"><span class="type">SoupMessage</span></a> is
<span class="emphasis"><em>not</em></span> thread-safe, so once you send a message on
the session, you must not interact with it from any thread other than
the one where it was sent.
</p>
</div>
<hr>
<div class="refsect2">
<a name="id-1.2.3.10"></a><h3>Sample Programs</h3>
<p>
A few sample programs are available in the
<span class="application">libsoup</span> sources, in the
<code class="literal">examples</code> directory:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem"><p>
<span class="bold"><strong><code class="literal">get</code></strong></span> is a simple command-line
HTTP GET utility using the asynchronous API.
</p></li>
<li class="listitem"><p>
<span class="bold"><strong><code class="literal">simple-proxy</code></strong></span> uses both the
client and server APIs to create a simple (and not very
RFC-compliant) proxy server. It shows how to use the <a class="link" href="SoupMessage.html#SoupMessageFlags" title="enum SoupMessageFlags"><code class="literal">SOUP_MESSAGE_OVERWRITE_CHUNKS</code></a>
flag when reading a message to save memory by processing each
chunk of the message as it is read, rather than accumulating
them all into a single buffer to process all at the end.
</p></li>
</ul></div>
<p>
More complicated examples are available in GNOME git.
</p>
</div>
</div>
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