Presentation from Lasso Summit 2006. Also see the paper at http://www.scribd.com/doc/919286/URL-Design

1. URL Design
– Methods to Use Friendly URLs

2. URL Design
– Methods to Use Friendly URLs
by Johan Sölve
Montania System AB, Sweden
www.montania.se

3. URL Design
– Methods to Use Friendly URLs
by Johan Sölve
Montania System AB, Sweden
www.montania.se
• Software and consulting company
• Business administration solutions
for small- and medium-sized
business

4. URL Design
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5. URL Design
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6. URL Design
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7. URL Design
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8. URL Design
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9. A URL is not a Filename
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10. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
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11. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
• This is not how things are intended
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12. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
• This is not how things are intended
• A URL is a reference to a resource
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13. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
• This is not how things are intended
• A URL is a reference to a resource
• Disconnect the URL from the server’s file system
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14. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
• This is not how things are intended
• A URL is a reference to a resource
• Disconnect the URL from the server’s file system
• Design URLs!
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15. A URL is not a Filename
• Servertotechnology file us think that a URL
makes
maps a physical
• This is not how things are intended
• A URL is a reference to a resource
• Disconnect the URL from the server’s file system
• Design URLs!
• Do URL Mapping!
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16. Choosing URLs
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17. Choosing URLs
• Short – easy to share
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18. Choosing URLs
• Short – easy to share
• Memorable – easy to remember
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19. Choosing URLs
• Short – easy to share
• Memorable – easy to remember
• Bookmark-able – easy to come back
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20. Choosing URLs
• Short – easy to share
• Memorable – easy to remember
• Bookmark-able – easy to come back
• An aid in site navigation – easy to use
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21. Choosing URLs
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22. Choosing URLs
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23. Choosing URLs
• Guess-able – easy to find what you’re looking for
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24. Choosing URLs
• Guess-able – easy to find what you’re looking for
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25. Choosing URLs
• Guess-able – easy to find what you’re looking for
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26. Choosing URLs
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27. Choosing URLs
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28. Choosing URLs
• Hackable – easy to navigate
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29. Choosing URLs
• Hackable – easy to navigate
• Persistent – easy to come back
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30. Choosing URLs
• Hackable – easy to navigate
• Persistent – easy to come back
• Technology Neutral – easy to grow
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31. Choosing URLs
• Hackable – easy to navigate
• Persistent – easy to come back
• Technology Neutral – easy to grow
• The acid test
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32. Choosing URLs
• Hackable – easy to navigate
• Persistent – easy to come back
• Technology Neutral – easy to grow
• The acid test
Can you read a URL to
someone over the phone?
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33. URL Design
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34. URL Design
• We know how we want the URL to look
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35. URL Design
• We know how we want the URL to look
• But the a physical file requires us to map a
server technology
URL to
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36. URL Design
• We know how we want the URL to look
• But the a physical file requires us to map a
server technology
URL to
• How can we implement URL Design?
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37. URL Design
• We know how we want the URL to look
• But the a physical file requires us to map a
server technology
URL to
• How can we implement URL Design?
URL Mapping
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38. URL Design
• We know how we want the URL to look
• But the a physical file requires us to map a
server technology
URL to
• How can we implement URL Design?
URL Mapping
Translate the URL to a Lasso file and parameters
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39. URL Mapping With Lasso
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40. URL Mapping With Lasso
• Web Server additions
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41. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
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42. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
‣ IISRewrite and ISAPI_Rewrite for IIS
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43. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
‣ IISRewrite and ISAPI_Rewrite for IIS
‣ WebSTAR Rewrite
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44. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
‣ IISRewrite and ISAPI_Rewrite for IIS
‣ WebSTAR Rewrite
+ Robust and powerful
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45. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
‣ IISRewrite and ISAPI_Rewrite for IIS
‣ WebSTAR Rewrite
+ Robust and powerful
– Dependent on web server
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46. URL Mapping With Lasso
• Web Server additions
‣ Apache mod_rewrite
‣ IISRewrite and ISAPI_Rewrite for IIS
‣ WebSTAR Rewrite
+ Robust and powerful
– Dependent on web server
Completely outside of Lasso – split logic, more to
learn
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47. URL Mapping With Lasso
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48. URL Mapping With Lasso
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49. URL Mapping With Lasso
• mod_rewrite example
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50. URL Mapping With Lasso
• mod_rewrite example
RewriteEngine On
#RewriteBase /
# Check to see if the request is a real file or directory
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !.*/Security
# Everything else gets sent to index.lasso
RewriteRule ^(.*)$ /index.lasso?response_filepath=/$1 [QSA,L,NS]
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51. URL Mapping With Lasso
• mod_rewrite example
RewriteEngine On
#RewriteBase /
# Check to see if the request is a real file or directory
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !.*/Security
# Everything else gets sent to index.lasso
RewriteRule ^(.*)$ /index.lasso?response_filepath=/$1 [QSA,L,NS]
mod_rewrite can take a bit of black
magic to master
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52. URL Mapping With Lasso
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53. URL Mapping With Lasso
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54. URL Mapping With Lasso
• Lasso Built-In using error.lasso
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55. URL Mapping With Lasso
• Lasso Built-In using error.lasso
Use a custom error.lasso page to trap requests
for non-existent files
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56. URL Mapping With Lasso
• Lasso Built-In using error.lasso
Use a custom error.lasso page to trap requests
for non-existent files
error.lasso
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57. URL Mapping With Lasso
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58. URL Mapping With Lasso
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59. URL Mapping With Lasso
• Lasso Built-In using [Define_AtBegin]
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60. URL Mapping With Lasso
• Lasso Built-In using [Define_AtBegin]
http://reference.omnipilot.com/LDML8Reference.LassoApp?tag=6564
prior to processing any code in the current page.
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61. Define_Atbegin as URL
processor
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62. Define_Atbegin as URL
processor
• Defines code that will be executed before each
page on a site is loaded or executed
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63. Define_Atbegin as URL
processor
• Defines code that will be executed before each
page on a site is loaded or executed
• Look at the requested URL and map it toany
a
Lasso file and parameters before loading
page for it
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64. Advantages with AtBegin
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65. Advantages with AtBegin
• Mostly self-contained within Lasso
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66. Advantages with AtBegin
• Mostly self-contained within Lasso
• More portable, less things to setup
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67. Advantages with AtBegin
• Mostly self-contained within Lasso
• More portable, less things to setup
• All logic kept within Lasso
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68. Advantages with AtBegin
• Mostly self-contained within Lasso
• More portable, less things to setup
• All logic kept within Lasso
• Logic can be integrated with rest of site and
database
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69. How Does it Work?
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70. How Does it Work?
Visitor
http://www.myweather.com/halmstad/weekend.lasso
Web Server
/halmstad/
Lasso weekend.las
so
Normal processing
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71. How Does it Work?
Visitor
Visitor
http://www.myweather.com/halmstad/weekend.lasso
http://www.myweather.com/halmstad/weekend
Web Server
/halmstad/
Lasso weekend.las
so
Web Server
Lasso
urlhandler_ urlhandler.
index.lasso
atbegin.lasso inc
AtBegin processing
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72. Web Server Configuration
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73. Web Server Configuration
• Needed to allow URLs without .lasso (optional)
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74. Web Server Configuration
• Needed to allow URLs without .lasso (optional)
• Apache config
<LocationMatch quot;^[^.]+$quot;>
# anywhere without file extensions
SetHandler lasso8-handler
</LocationMatch>
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75. Web Server Configuration
• Needed to allow URLs without .lasso (optional)
• Apache config
<LocationMatch quot;^[^.]+$quot;>
# anywhere without file extensions
SetHandler lasso8-handler
</LocationMatch>
• IIS 6.0 on Windows 2003 Server
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76. Web Server Configuration
• Needed to allow URLs without .lasso (optional)
• Apache config
<LocationMatch quot;^[^.]+$quot;>
# anywhere without file extensions
SetHandler lasso8-handler
</LocationMatch>
• IIS 6.0 on Windows 2003 Server
Wildcard Application Mapping to send requests to
Lasso on a folder-by-folder basis
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77. Lasso Configuration
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78. Lasso Configuration
• Define_AtBegin or globally LassoStartup either
must be in
for a Lasso Site
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79. Lasso Configuration
• Define_AtBegin or globally LassoStartup either
must be in
for a Lasso Site
urlhandler_atbegin.lasso
<?LassoScript
Define_AtBegin: {
if: file_exists: '/urlhandler.inc';
include: '/urlhandler.inc';
/if;
};
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80. Lasso Configuration
• Define_AtBegin must bedefinesLassoScript that either
{ } in LassoStartup
a Compund
Expression, a
for a Lasso Site or globally in a variable and
can be stored
urlhandler_atbegin.lasso executed later.
<?LassoScript
Define_AtBegin: {
if: file_exists: '/urlhandler.inc';
include: '/urlhandler.inc';
/if;
};
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81. Lasso Configuration
• Define_AtBegin or globally LassoStartup either
must be in
for a Lasso Site
urlhandler_atbegin.lasso
<?LassoScript
Define_AtBegin: {
if: file_exists: '/urlhandler.inc';
include: '/urlhandler.inc';
/if;
};
We want to keep this as generic and transparent as
possible
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82. Lasso Configuration
• Define_AtBegin or globally LassoStartup either
must be in
for a Lasso Site
urlhandler_atbegin.lasso
<?LassoScript
Define_AtBegin: {
if: file_exists: '/urlhandler.inc';
include: '/urlhandler.inc';
/if;
};
We want to keep this as generic and transparent as
possible
If urlhandler.inc is not present in a virtual host,
everything works normally
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83. The URL Handler
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84. The URL Handler
• All Lasso requests are passing through one single
spot
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85. The URL Handler
• All Lasso requests are passing through one single
spot
• Parse the requested URL by looking at
[response_filepath]
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86. The URL Handler
• All Lasso requests are passing through one single
spot
• Parse the requested URL by looking at
[response_filepath]
• Send the result of the parsing to the actual Lasso
file by setting variables
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87. The URL Handler
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88. The URL Handler
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89. The URL Handler
• ExampleofURL handler for a News and Products
section a site
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90. The URL Handler
• ExampleofURL handler for a News and Products
section a site
urlhandler.inc
<?LassoScript
// this file is called by the atbegin handler, so it is executed
// before any page is being processed.
if: response_filepath -> (endswith: '.lasso') || response_filepath ->
(endswith: '.lassoapp');
// don't do anything for normal .lasso and .lassoapp requests
else;
if: response_filepath -> (beginswith: '/news/')
|| response_filepath -> (beginswith: '/products/');
var: 'url_path'=response_filepath,
'section'='';
$url_path -> (removeleading: '/');
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91. The URL Handler
• ExampleofURL handler for a News and Products
section a site
if: !($url_path -> endswith: '/');
$url_path += '/';
/if;
if: $url_path -> (beginswith: 'news/');
// check for pattern /news/2004/12/31/keyword/
//using regular expression
var: 'pathcheck'=(string_findregexp: $url_path,
-find='^news/(20d{2})/(0[1-9]|1[0-2])/'
+ '([^/]+)/([^/]*)');
if: $pathcheck -> size >= 5;
$section = 'news';
var: 'newsdate'=($pathcheck -> (get: 2))
+ '/' + ($pathcheck -> (get: 3))
+ '/' + ($pathcheck -> (get: 4)); 18 of 41

92. The URL Handler
• ExampleofURL handler for a News and Products
section a site
$newsdate = (date: $newsdate, -format='%Y/%m/%d');
var: 'newskeyword'=($pathcheck -> (get: 5)),
var: 'newsextra'='';
if: $pathcheck -> size >= 6;
$newsextra=($pathcheck -> (get: 6));
/if;
/if;
else: $url_path -> beginswith: 'products/';
$section = 'products';
// split up the path in components
$url_path = $url_path -> (split: '/');
/if;
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93. The URL Handler
• ExampleofURL handler for a News and Products
section a site
// run site
// use absolute path!
$__HTML_REPLY__ = include: '/index.lasso';
abort;
/if;
/if;
?>
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94. The URL Handler
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95. The URL Handler
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96. The URL Handler
• index.lasso now has these variables:
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97. The URL Handler
• index.lasso now has these variables:
$url_path
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98. The URL Handler
• index.lasso now has these variables:
$url_path
$section tells the site what main section we are in.
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99. The URL Handler
• index.lasso now has these variables:
$url_path
$section tells the site what main section we are in.
• For the news section also these variables
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100. The URL Handler
• index.lasso now has these variables:
$url_path
$section tells the site what main section we are in.
• For the news section also these variables
$newsdate publication date, used when getting the news article from database
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101. The URL Handler
• index.lasso now has these variables:
$url_path
$section tells the site what main section we are in.
• For the news section also these variables
$newsdate publication date, used when getting the news article from database
$newskeyword an identification string for the news article
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102. The URL Handler
• index.lasso now has these variables:
$url_path
$section tells the site what main section we are in.
• For the news section also these variables
$newsdate publication date, used when getting the news article from database
$newskeyword an identification string for the news article
$newsextra optional extra item, for example ‘comments’
Try it
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103. Running The Site
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104. Running The Site
• [Define_AtBegin] will never output anything to
the web page by itself
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105. Running The Site
• [Define_AtBegin] will never output anything to
the web page by itself
• Explicitly put the output to the page buffer
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106. Running The Site
• [Define_AtBegin] will never output anything to
the web page by itself
• Explicitly put the output to the page buffer
• [abort] so Lasso doesn’t try to run the
requested file again afterwards
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107. Running The Site
• [Define_AtBegin] will never output anything to
the web page by itself
• Explicitly put the output to the page buffer
• [abort] so Lasso doesn’t try to run the
requested file again afterwards
$__HTML_REPLY__ = include: '/index.lasso';
abort;
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108. Error Handling
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109. Error Handling
• The requested URL is not a physical file so a File
Not Found can technically not happen
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110. Error Handling
• The requested URL is not a physical file so a File
Not Found can technically not happen
• For invalid URLs a be provided status code and
proper HTTP
error page should
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111. Error Handling
• The requested URL is not a physical file so a File
Not Found can technically not happen
• For invalid URLs a be provided status code and
proper HTTP
error page should
• Invalid URL: 404 Not Found
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112. Error Handling
• The requested URL is not a physical file so a File
Not Found can technically not happen
• For invalid URLs a be provided status code and
proper HTTP
error page should
• Invalid URL: 404 Not Found
• URL no longer available: 410 Gone
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113. Error Handling
• The requested URL is not a physical file so a File
Not Found can technically not happen
• For invalid URLs a be provided status code and
proper HTTP
error page should
• Invalid URL: 404 Not Found
• URL no longer available: 410 Gone
• See http://www.w3.org/Protocols/HTTP/1.1/
spec.html#Status-Codes
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114. Error Handling
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115. Error Handling
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116. Error Handling
• Custom tag to set HTTP status
http://tagswap.net/setHTTPstatus
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117. Error Handling
• Custom tag to set HTTP status
http://tagswap.net/setHTTPstatus
define_tag: 'setHTTPstatus', -required='statuscode';
// replace status code but keep leading HTTP with version
$__http_header__ = (string_replaceregexp: $__http_header__,
-find='(^HTTPS+)s+.*?rn',
-replace='1 ' + #statuscode + 'rn');
/define_tag;
setHTTPstatus: '404 Not Found';
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118. Watch Out
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119. Watch Out
• Important to debugthe site might fail. every
carefully. Otherwise
page requested on
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120. Watch Out
• Important to debugthe site might fail. every
carefully. Otherwise
page requested on
• Can’t use abort as debug method – nothing at all
will output
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121. Other uses for AtBegin
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122. Other uses for AtBegin
• Virtual Host handling
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123. Other uses for AtBegin
• Virtual Host handling
• Debugging
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124. Other uses for AtBegin
• Virtual Host handling
• Debugging
• Timing of pages
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125. Other uses for AtBegin
• Virtual Host handling
• Debugging
• Timing of pages
• Page optimization
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126. Other uses for AtBegin
• Virtual Host handling
• Debugging
• Timing of pages
• Page optimization
• Protected downloads
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127. Other uses for AtBegin
• Virtual Host handling
• Debugging
• Timing of pages
• Page optimization
• Protected downloads
• Protection of .inc files
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128. Other uses for AtBegin
• Virtual Host handling
• Debugging
• Timing of pages
• Page optimization
• Protected downloads
• Protection of .inc files
• Locking down SiteAdmin.LassoApp
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129. Virtual Host Handling
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130. Virtual Host Handling
• Look at the ‘host’ field in the request header
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131. Virtual Host Handling
• Look at the ‘host’ field in the request header
• Direct the request to the site’s folder
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132. Virtual Host Handling
• Look at the ‘host’ field in the request header
• Direct the request to the site’s folder
- Not for images and other external files
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133. Virtual Host Handling
• Look at the ‘host’ field in the request header
• Direct the request to the site’s folder
- Not for images and other external files
- Must use relative paths for includes
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134. Virtual Host Handling
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135. Virtual Host Handling
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136. Virtual Host Handling
<?LassoScript
var: 'url_path'=response_filepath,
'host'=client_host; // http://tagswap.net/client_host
// massage the hostname
// www.montania.se turns to montania_se
$host -> (removeleading: 'www.');
$host -> (replace: '.', '_');
// direct the request to the virtual host's subfolder
$url_path = '/' + $host + $url_path;
// run site
$__HTML_REPLY__ = include: $url_path;
abort;
?>
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137. Debugging
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138. Debugging
• If you suspectitthat a page makes Lasso to crash
but can’t find
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139. Debugging
• If you suspectitthat a page makes Lasso to crash
but can’t find
• Log the page request to a database in AtBegin
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140. Debugging
• If you suspectitthat a page makes Lasso to crash
but can’t find
• Log the page request to a database in AtBegin
• Remove the log entry in AtEnd
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141. Debugging
• If you suspectitthat a page makes Lasso to crash
but can’t find
• Log the page request to a database in AtBegin
• Remove the log entry in AtEnd
• Leftover entries are pages that have crashed
Credit goes to Bil Corry for this idea
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142. Debugging
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143. Debugging
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144. Debugging
<?LassoScript
define_atbegin( {
if: !(global_defined: 'global_pagedebug');
global: 'global_pagedebug' = map;
/if;
var: 'pagedebug_key'=lasso_uniqueid;
$global_pagedebug -> (insert: $pagedebug_key
= (date -> format: '%Q %T') + ': '
+ server_name + response_filepath);
define_atend( {
$global_pagedebug -> (remove: $pagedebug_key);
}
);
});
?>
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145. Timing of Pages
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146. Timing of Pages
• AtEnd handler logs page requests with
processing times
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147. Timing of Pages
• AtEnd handler logs page requests with
processing times
<?LassoScript
// Script written by Miles
// http://tagswap.net/PageLogConsole
define_atbegin({
var('start_time' = _date_msec);
define_atend({
log_detail(response_localpath + ': '
+ (_date_msec - $start_time));
} );
} );
?>
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148. Page Optimization
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149. Page Optimization
• AtEnd to remove extra whitespace
http://tagswap.net/lp_page_trim (Bil Corry)
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150. Page Optimization
• AtEnd to remove extra whitespace
http://tagswap.net/lp_page_trim (Bil Corry)
• Gzip compression of pages
http://www.omnipilot.com/TotW.1768.8959.lasso
(Fletcher Sandbeck)
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151. Protected Downloads
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152. Protected Downloads
• Set Lasso to process the download file type
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153. Protected Downloads
• Set Lasso to process the download file type
• AtBegin handler authorizes the download
request
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154. Protected Downloads
• Set Lasso to process the download file type
• AtBegin handler authorizes the download
request
• If request is ok, use file_stream to serve the
requested file
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155. Protection of .inc Files
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156. Protection of .inc Files
• Make .inc files processed by Lasso in Web server
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157. Protection of .inc Files
• Make .inc files processed by Lasso in Web server
<?LassoScript
define_atbegin({
if: response_filepath -> (endswith: '.inc');
$__HTML_REPLY__ = '<h1>Not authorized</h1>';
// set proper result code too
abort;
/if;
} );
?>
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158. Locking down
SiteAdmin.LassoApp
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159. Locking down
SiteAdmin.LassoApp
• To make from SiteAdmin.LassoApp can only be
sure
reached the server machine
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160. Locking down
SiteAdmin.LassoApp
• To make from SiteAdmin.LassoApp can only be
sure
reached the server machine
<?LassoScript
define_atbegin({
if: response_filepath -> split: '/' -> last
-> (beginswith: 'siteadmin.')
&& response_filepath -> (endswith: '.lassoapp')
&& client_ip != '127.0.0.1';
$__HTML_REPLY__ = '<h1>Not authorized</h1>';
// set proper result code too
abort;
/if;
} );
?>
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161. URL Design
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162. URL Design
• Disconnect the URL from the server’s file
system
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163. URL Design
• Disconnect the URL from the server’s file
system
• AtBegin lets us do URL mapping all within Lasso
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164. URL Design
• Disconnect the URL from the server’s file
system
• AtBegin lets us do URL mapping all within Lasso
• AtBegin has many other interesting uses
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