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<h1 id="2101">URL Mapping (Friendly URLs)</h1>

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<p id="230222" class="block-content">
The TUrlMapping module allows PRADO to construct and recognize friendly URLs
based on specific patterns.
</p>

<p id="230223" class="block-content">
TUrlMapping consists of a list of URL patterns which are used to match
against the currently requested URL. The first matching pattern will then
be used to decompose the URL into request parameters (accessible via
<tt>$this->Request['paramname']</tt>). The patterns can also be used to
construct customized URLs. In this case, the parameters in an applied
pattern will be replaced with the corresponding GET variable values.
</p>

<p id="230224" class="block-content">
To use <tt>TUrlMapping</tt>, one must set the <tt>UrlManager</tt> property of the <tt>THttpRequest</tt> module as the <tt>TUrlMapping</tt> module ID. See following for an example,
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<modules>
    <module id="request" class="THttpRequest" UrlManager="friendly-url" />
    <module id="friendly-url" class="System.Web.TUrlMapping">
        <url ServiceParameter="Posts.ViewPost" pattern="post/{id}/" parameters.id="\d+" />
        <url ServiceParameter="Posts.ListPost" pattern="archive/{time}/" parameters.time="\d{6}" />
        <url ServiceParameter="Posts.ListPost" pattern="category/{cat}/" parameters.cat="\d+" />
    </module>
</modules>
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<p id="230225" class="block-content">
The above example is part of the application configuration of the <tt>blog</tt> demo in the PRADO release. It enables recognition of the following URL formats:
</p>
<ul id="u1" class="block-content">
  <li><tt>/index.php/post/123</tt> is recognized as <tt>/index.php?page=Posts.ViewPost&amp;id=123</tt></li>
  <li><tt>/index.php/archive/200605</tt> is recognized as <tt>/index.php?page=Posts.ListPost&amp;time=200605</tt></li>
  <li><tt>/index.php/category/2</tt> is recognized as <tt>/index.php?page=Posts.ListPost&amp;cat=2</tt></li>
</ul>

<p id="230226" class="block-content">
The <tt>ServiceParameter</tt> and <tt>ServiceID</tt> (the default ID is 'page')
set the service parameter and service ID, respectively, of the <a href="?page=Fundamentals.Modules">Request module</a>. The service parameter for the <tt>TPageService</tt> service is the Page class name, e.g., for an URL "index.php?page=Home", "page" is the service ID and the service parameter is "Home". Other services may use the service parameter and ID differently. See <a href="?page=Fundamentals.Services">Services</a> for further details.
</p>

<div class="info"><b class="tip">Info:</b>
The <tt>TUrlMapping</tt> must be configured before the
<a href="?page=Fundamentals.Modules">request module</a> resolves the request.
This means delcaring the <tt>TUrlMapping</tt> outside of the
<tt>&lt;services&gt;</tt> element in the <a href="?page=Configurations.AppConfig">application configuration</a>.
Specifying the mappings in the per directory <tt>config.xml</tt> is not supported.
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<h2 id="46023">Specifying URL Patterns</h2>
<p id="230227" class="block-content">
<tt>TUrlMapping</tt> enables recognition of customized URL formats based on a list prespecified of URL patterns. Each pattern is specified in a <tt>&lt;url&gt;</tt> tag.
</p>

<p id="230228" class="block-content">
The <tt>Pattern</tt> and <tt>Parameters</tt> attribute
values are regular expression patterns that
determine the mapping criteria. The <tt>Pattern</tt> property takes
a regular expression with parameter names enclosed between a left brace '<tt>{</tt>'
and a right brace '<tt>}</tt>'. The patterns for each parameter can be set
using <tt>Parameters</tt> attribute collection.
For example,
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<url ServiceParameter="ArticleView" pattern="articles/{year}/{month}/{day}"
     parameters.year="\d{4}" parameters.month="\d{2}" parameters.day="\d+" />
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The example is equivalent to the following regular expression (it uses the "named group" feature in regular expressions available in PHP):
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<url ServiceParameter="ArticleView"
     RegularExpression="/articles\/(?P<year>\d{4})\/(?P<month>\d{2})\/(?P<day>\d+)/u" />
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<p id="230229" class="block-content">
In the above example, the pattern contains 3 parameters named "<tt>year</tt>",
"<tt>month</tt>" and "<tt>day</tt>". The pattern for these parameters are,
respectively, "<tt>\d{4}</tt>" (4 digits), "<tt>\d{2}</tt>" (2 digits)
and "<tt>\d+</tt>" (1 or more digits).
Essentially, the <tt>Parameters</tt> attribute name and values are used
 as substrings in replacing the placeholders in the <tt>Pattern</tt> string
to form a complete regular expression string.
</p>

<div class="note"><b class="tip">Note:</b> If you intended to use the <tt>RegularExpression</tt>
property you need to escape the slash in regular expressions.
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<p id="230230" class="block-content">Following from the above pattern example,
an URL <tt>http://example.com/index.php/articles/2006/07/21</tt> will be matched
and valid.  However, <tt>http://example.com/index.php/articles/2006/07/hello</tt> is not
valid since the <tt>day</tt> parameter pattern is not satisfied.
In the default <tt>TUrlMappingPattern</tt> class, the pattern is matched against the
<b>PATH_INFO</b> part of the URL only. For example, only the <tt>/articles/2006/07/21</tt>
portion of the URL is considered.
</p>

<p id="230231" class="block-content">
The mapped request URL is equivalent to <tt>index.php?page=ArticleView&amp;year=2006&amp;month=07&amp;day=21</tt>.
The request parameter values are available through the standard <tt>Request</tt>
object. For example, <tt>$this->Request['year']</tt>.
</p>

<p id="230232" class="block-content">The URL mapping are evaluated in order they are placed and only the first pattern that matches
 the URL will be used. Cascaded mapping can be achieved by placing the URL mappings
 in particular order. For example, placing the most specific mappings first.
</p>

<p class="block-content">Since version 3.1.4, Prado also provides wildcard patterns to use friendly URLs 
for a bunch of pages in a directory with a single rule. Therefore you can use the <tt>{*}</tt> wildcard
in your pattern to let Prado know, where to find the ServiceID in your request URL. You can also specify
parameters with these patterns if a lot of pages share common parameters.</p>

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<url ServiceParameter="Posts.*" pattern="posts/{*}/{id}" parameters.id="\d+" />
<url ServiceParameter="Posts.*" pattern="posts/{*}" />
<url ServiceParameter="Static.Info.*" pattern="info/{*}" />
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<p class="block-content">With these rules, any of the following URLs will be recognized:
<ul id="u1" class="block-content">
  <li><tt>/index.php/post/ViewPost/123</tt> is recognized as <tt>/index.php?page=Posts.ViewPost&amp;id=123</tt></li>
  <li><tt>/index.php/post/ListPost/123</tt> is recognized as <tt>/index.php?page=Posts.ListPost&amp;id=123</tt></li>
  <li><tt>/index.php/post/ListPost/123</tt> is recognized as <tt>/index.php?page=Posts.ListPost&amp;id=123</tt></li>
  <li><tt>/index.php/post/MyPost</tt> is recognized as <tt>/index.php?page=Posts.MyPost</tt></li>
  <li><tt>/index.php/info/Conditions</tt> is recognized as <tt>/index.php?page=Static.Info.Conditions</tt></li>
  <li><tt>/index.php/info/About</tt> is recognized as <tt>/index.php?page=Static.Info.About</tt></li>
</ul>
</p>

<p id="250001" class="block-content">As above, put more specific rules before more common rules as the first matching rule will be used.</p>

<p id="250002" class="block-content">To make configuration of friendly URLs for multiple pages even easier, you can also use <tt>UrlFormat="Path"</tt> 
in combination with wildcard patterns. In fact, this feature only is available in combination with wildcard rules:</P>

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<url ServiceParameter="user.admin.*" pattern="admin/{*}" UrlFormat="Path"/>
<url ServiceParameter="*" pattern="{*}" UrlFormat="Path" />
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<p class="block-content">Parameters will get appended to the specified patterns as name/value pairs, separated by a "/". 
(You can change the separator character with <tt>UrlParamSeparator</tt>.)
<ul id="u1" class="block-content">
  <li><tt>/index.php/list/cat/15/month/12</tt> is recognized as <tt>/index.php?page=list&amp;cat=15&amp;month=12</tt></li>
  <li><tt>/index.php/edit/id/12</tt> is recognized as <tt>/index.php?page=list&amp;id=12</tt></li>
  <li><tt>/index.php/show/name/foo</tt> is recognized as <tt>/index.php?page=show&amp;name=foo</tt></li>
  <li><tt>/index.php/admin/edit/id/12</tt> is recognized as <tt>/index.php?page=user.admin.edit&amp;id=12</tt></li>
</ul>
</p>

<h2 id="46024">Constructing Customized URLs</h2>
<p id="230233" class="block-content">
Since version 3.1.1, <tt>TUrlMapping</tt> starts to support constructing customized URLs based on the provided patterns. To enable this feature, set <tt>TUrlMapping.EnableCustomUrl</tt> to true. When <tt>THttpRequest.constrcutUrl()</tt> is invoked, the actual URL construction work will be delegated to a matching <tt>TUrlMappingPattern</tt> instance. It replaces the parameters in the pattern with the corresponding GET variables passed to <tt>constructUrl()</tt>.
</p>

<p id="230234" class="block-content">
A matching pattern is one whose <tt>ServiceID</tt> and <tt>ServiceParameter</tt> properties are the same as those passed to <tt>constructUrl()</tt> and whose named parameters are found in the GET variables. For example, <tt>constructUrl('Posts.ListPost',array('cat'=>2))</tt> will use the third pattern in the above example.
<p id="250003" class="block-content">

<p id="230235" class="block-content">
By default, <tt>TUrlMapping</tt> will construct URLs prefixed with the currently requesting PHP script path, such as <tt><b>/path/to/index.php</b>/article/3</tt>. Users may change this behavior by explicitly specifying the URL prefix through its <tt>UrlPrefix</tt> property. For example, if the Web server configuration treats <tt>index.php</tt> as the default script, we can set <tt>UrlPrefix</tt> as <tt>/path/to</tt> and the constructed URL will look like <tt>/path/to/article/3</tt>.
</p>

<div class="note"><b class="tip">Note:</b> If you use <tt>constructUrl()</tt> with string parameters that contain slashes ("/") they will get encoded to %2F. By default most Apache installations give a "404 Not found" if a URL contains a %2F. You can add <tt>AllowEncodedSlashes On</tt> to your <tt>VirtualHost</tt> configuration to resolve this. (Available since Apache 2.0.46).
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