reference/var/functions/serialize.xml
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8cdc6621f9826d04abc3e50438c010804d7e8683
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<methodparam><type>mixed</type><parameter>value</parameter></methodparam>
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</methodsynopsis>
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<para>
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Generates a storable representation of a value
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Generates a storable representation of a value.
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</para>
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<para>
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This is useful for storing or passing PHP values around without
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<listitem>
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<para>
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The value to be serialized. <function>serialize</function>
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handles all types, except the <type>resource</type>-type.
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handles all types, except the <type>resource</type>-type and some <type>object</type>s (see note below).
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You can even <function>serialize</function> arrays that contain
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references to itself. Circular references inside the array/object you
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are serializing will also be stored. Any other
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reference will be lost.
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</para>
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<para>
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When serializing objects, PHP will attempt to call the member function
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<link linkend="language.oop5.magic">__sleep</link> prior to serialization.
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When serializing objects, PHP will attempt to call the member functions
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<link linkend="object.serialize">__serialize()</link> or
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<link linkend="object.sleep">__sleep()</link> prior to serialization.
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This is to allow the object to do any last minute clean-up, etc. prior
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to being serialized. Likewise, when the object is restored using
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<function>unserialize</function> the <link
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linkend="language.oop5.magic">__wakeup</link> member function is called.
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<function>unserialize</function> the <link linkend="object.unserialize">__unserialize()</link> or
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<link linkend="object.wakeup">__wakeup()</link> member function is called.
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</para>
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<note>
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<para>
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Returns a string containing a byte-stream representation of
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<parameter>value</parameter> that can be stored anywhere.
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</para>
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<para>
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Note that this is a binary string which may include null bytes, and needs
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to be stored and handled as such. For example,
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<function>serialize</function> output should generally be stored in a BLOB
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field in a database, rather than a CHAR or TEXT field.
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</para>
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</refsect1>
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<refsect1 role="examples">
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if (!odbc_execute($stmt, $sqldata)) {
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$stmt = odbc_prepare($conn,
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"INSERT INTO sessions (id, data) VALUES(?, ?)");
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if (!odbc_execute($stmt, $sqldata)) {
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if (!odbc_execute($stmt, array_reverse($sqldata))) {
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/* Something went wrong.. */
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}
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}
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</para>
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</refsect1>
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<refsect1 role="changelog">
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&reftitle.changelog;
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<para>
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<informaltable>
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<tgroup cols="2">
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<thead>
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<row>
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<entry>&Version;</entry>
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<entry>&Description;</entry>
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</row>
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</thead>
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<tbody>
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<row>
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<entry>4.0.7</entry>
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<entry>
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The object serialization process was fixed.
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</entry>
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</row>
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</tbody>
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</tgroup>
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</informaltable>
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</para>
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</refsect1>
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<refsect1 role="notes">
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&reftitle.notes;
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<note>
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<para>
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It is not possible to serialize PHP built-in objects.
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Note that many built-in PHP objects cannot be serialized. However, those with
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this ability either implement the <interfacename>Serializable</interfacename> interface or the
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magic <link linkend="object.serialize">__serialize()</link>/<link linkend="object.unserialize">__unserialize()</link>
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or <link linkend="object.sleep">__sleep()</link>/<link linkend="object.wakeup">__wakeup()</link> methods. If an
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internal class does not fulfill any of those requirements, it cannot reliably be
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serialized.
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</para>
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<para>
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There are some historical exceptions to the above rule, where some internal objects
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could be serialized without implementing the interface or exposing the methods.
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</para>
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</note>
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<warning>
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<para>
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When <function>serialize</function> serializes objects, the leading backslash is not included in the class name of namespaced classes for maximum compatibility.
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</para>
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</warning>
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</refsect1>
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<refsect1 role="seealso">
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<para>
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<simplelist>
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<member><function>unserialize</function></member>
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<member><function>var_export</function></member>
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<member><function>json_encode</function></member>
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<member><link linkend="language.oop5.serialization">Serializing Objects</link></member>
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<member><link linkend="object.sleep">__sleep()</link></member>
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<member><link linkend="object.wakeup">__wakeup()</link></member>
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<member><link linkend="object.serialize">__serialize()</link></member>
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<member><link linkend="object.unserialize">__unserialize()</link></member>
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</simplelist>
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</para>
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</refsect1>
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