php-doc-en/functions/outcontrol.xml
2000-08-29 21:10:19 +00:00

266 lines
7.6 KiB
XML

<reference id="ref.outcontrol">
<title>Output Control Functions</title>
<titleabbrev>Output Control</titleabbrev>
<partintro>
<para>
The Output Control functions allow you to control when output is
sent from the script. This can be useful in several different
situations, especially if you need to send headers to the browser
after your script has began outputing data. The Output Control
functions do not affect headers sent using
<function>header</function> or <function>setcookie</function>,
only functions such as <function>echo</function> and data between
blocks of PHP code.
</para>
<para>
<example>
<title>Output Control example</title>
<programlisting role="php">
&lt;?php
ob_start();
echo "Hello\n";
setcookie ("cookiename", "cookiedata");
ob_end_flush();
?&gt;
</programlisting>
</example>
</para>
<para>
In the above example, the output from <function>echo</function>
would be stored in the output buffer until
<function>ob_end_flush</function> was called. In the mean time,
the call to <function>setcookie</function> successfully stored a
cookie without causing an error. (You can not normally send
headers to the browser after data has already been sent.)
</para>
<para>
See also <function>header</function> and
<function>setcookie</function>.
</para>
</partintro>
<refentry id="function.flush">
<refnamediv>
<refname>flush</refname>
<refpurpose>Flush the output buffer</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>flush</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<simpara>
Flushes the output buffers of PHP and whatever backend PHP is
using (CGI, a web server, etc.) This effectively tries to push
all the output so far to the user's browser.
</simpara>
</refsect1>
</refentry>
<refentry id="function.ob-start">
<refnamediv>
<refname>ob_start</refname>
<refpurpose>Turn on output buffering</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>ob_start</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<para>
This function will turn output buffering on. While output buffering
is active no output is sent from the script, instead the output
is stored in an internal buffer.
</para>
<para>
The contents of this internal buffer may be copied into a string
variable using <function>ob_get_contents</function>. To output
what is stored in the internal buffer, use
<function>ob_end_flush</function>. Alternatively,
<function>ob_end_clean</function> will silently discard the
buffer contents.
</para>
<para>
See also <function>ob_get_contents</function>,
<function>ob_end_flush</function>,
<function>ob_end_clean</function>, and
<function>ob_implicit_flush</function>
</para>
</refsect1>
</refentry>
<refentry id="function.ob-get-contents">
<refnamediv>
<refname>ob_get_contents</refname>
<refpurpose>
Return the contents of the output buffer
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>ob_get_contents</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<para>
This will return the contents of the output buffer or FALSE, if
output buffering isn't active.
</para>
<para>
See also <function>ob_start</function> and
<function>ob_get_length</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.ob-get-length">
<refnamediv>
<refname>ob_get_length</refname>
<refpurpose>
Return the length of the output buffer
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>string <function>ob_get_length</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<para>
This will return the length of the contents in the output buffer
or FALSE, if output buffering isnt't active.
</para>
<para>
See also <function>ob_start</function> and
<function>ob_get_contents</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.ob-end-flush">
<refnamediv>
<refname>ob_end_flush</refname>
<refpurpose>
Flush (send) the output buffer and turn off output buffering
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>ob_end_flush</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<para>
This function will send the contents of the output buffer (if
any) and turn output buffering off. If you want to further
process the buffer's contents you have to call
<function>ob_get_contents</function> before
<function>ob_end_flush</function> as the buffer contents are
discarded after <function>ob_get_contents</function> is called.
</para>
<para>
See also <function>ob_start</function>,
<function>ob_get_contents</function>, and
<function>ob_end_clean</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.ob-end-clean">
<refnamediv>
<refname>ob_end_clean</refname>
<refpurpose>
Clean (erase) the output buffer and turn off output buffering
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>ob_end_clean</function></funcdef>
<void/>
</funcprototype>
</funcsynopsis>
<para>
This function discards the contents of the output buffer and
turns off output buffering.
</para>
<para>
See also <function>ob_start</function> and
<function>ob_end_flush</function>.
</para>
</refsect1>
</refentry>
<refentry id="function.ob-implicit-flush">
<refnamediv>
<refname>ob_implicit_flush</refname>
<refpurpose>
Turn implicit flush on/off
</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<funcsynopsis>
<funcprototype>
<funcdef>void <function>ob_implicit_flush</function></funcdef>
<paramdef>int
<parameter><optional>flag</optional></parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
<para>
<function>ob_implicit_flush</function> will turn implicit
flushing on or off (if no <parameter>flag</parameter> is given,
it defaults to on). Implicit flushing will result in a flush
operation after every output call, so that explicit calls to
<function>flush</function> will no longer be needed.
</para>
<para>
Turning implicit flushing on will disable output buffering, the
output buffers current output will be sent as if
<function>ob_end_flush</function> had been called.
</para>
<para>
See also <function>flush</function>,
<function>ob_start</function>, and
<function>ob_end_flush</function>.
</para>
</refsect1>
</refentry>
</reference>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
sgml-parent-document:nil
sgml-default-dtd-file:"../../manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
-->