Parse Order Pro

Be a Pro with ExpressionEngine's Parse Order.

Transcript

1. Parse Order Pro By Lodewijk Schutte ~ Low, October 2011
2. Hi! I'm Low!
3. gotolow.com
5. ExpressionEngine’s Parse Order In what order does EE parse its variables and tags? Read URI to determine template Get template from DB, check permissions & authentication Get template from file Return static template 1. Parse snippets / global variables, segment variables and embed variables * Parse date string constants Parse {template_edit_date} and {current_time} If present, get cached template, then go to #7 2. Parse PHP on Input 3. Parse simple conditionals: segment, embed, global variables 4. Assign and parse preload_replace variables 5. Parse module and plugin tags 6. Parse PHP on Output Write cache file 7. Parse advanced conditionals 8. Process embedded templates Redirect 9. Parse User Defined global variables and others: {hits} {ip_address} {gzip_mode} {app_version} {group_title} {member_group} gotolow.com/parse-order
7. Parse Order Parse Order
9. How does parsing work? •Document (template) •Markers (variables and tags) •Values (data) •Find & Replace (parsing)
10. Parse Order Parse Order
11. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  3 {a} {b} {a} {c} {c}
12. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  3 1 {b} 1 {c} {c}
13. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  3 1 2 1 {c} {c}
14. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  3 1 2 1 3 3
15. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  3 1 2 1 3 3
17. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} {a} {d} {b} {a} {c} {c} {e} {e}
18. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 {d} {b} 1 {c} {c} {e} {e}
19. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 {d} 2 1 {c} {c} {e} {e}
20. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 {d} 2 1 {d} {d} {e} {e}
21. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 3 2 1 3 3 {e} {e}
22. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 3 2 1 3 3 {a} {a}
23. Parse Order {a}  =>  1 {b}  =>  2 {c}  =>  {d} {d}  =>  3 {e}  =>  {a} 1 3 2 1 3 3 {a} {a}
25. Parse Order in ExpressionEngine
26. Early vs. Late stuff {exp:tags} more  stuff Early Late
27. Input vs. Output stuff {exp:tags} more  stuff PHP  on  Input PHP  on  Output
28. Variables
29. Variable Scope
30. Variable Scope Global Variables: all templates
31. Variable Scope Regional Variables: single template
32. Variable Scope Local Variables: single template, inside tag
33. Global Variables •Parsed Early • Snippets • Config variables • Segment variables •Parsed Late • User Defined Global Variables • "Standard Global Variables" http://bit.ly/standard-global-vars
34. Regional Variables •Parsed Early • Embed variables • Preload replace variables * *) Parsed early-ish
35. Local Variables •Parsed during Tags •Can be more complex • Variable parameters • Variable pairs
36. All Variables snippets config  vars segment  vars embed  vars preload  replace  vars {exp:tags}  local  vars  {/exp:tags} user  defined  vars standard  vars
38. Variables Example 1
39. {gv_header} <h1>{sn_{segment_1}_title}  containing  {username}</h1> {exp:channel:entries  channel="{segment_1}"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
40. Snippets {gv_header} <h1>{sn_{segment_1}_title}  containing  {username}</h1> {exp:channel:entries  channel="{segment_1}"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
41. {gv_header} <h1>{sn_{segment_1}_title}  containing  {username}</h1> {exp:channel:entries  channel="{segment_1}"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
42. Segment vars {gv_header} <h1>{sn_{segment_1}_title}  containing  {username}</h1> {exp:channel:entries  channel="{segment_1}"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
43. {gv_header} <h1>{sn_news_title}  containing  {username}</h1> {exp:channel:entries  channel="news"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
44. Tags & Local vars {gv_header} <h1>{sn_news_title}  containing  {username}</h1> {exp:channel:entries  channel="news"    search:cf_summary="{username}"}        <h2>{title}</h2>        {cf_summary} {/exp:channel:entries} {gv_footer}
45. {gv_header} <h1>{sn_news_title}  containing  {username}</h1> {gv_footer}
46. User Defined Global vars {gv_header} <h1>{sn_news_title}  containing  {username}</h1> {gv_footer}
47. <html> <head>    <title>{sn_{segment_1}_title}  -­‐  {site_name}</title> </head> <body> <h1>{sn_news_title}  containing  {username}</h1> <p>&copy;  {current_date  format="%Y"}</p> </body> </html>
48. Standard Global vars <html> <head>    <title>{sn_{segment_1}_title}  -­‐  {site_name}</title> </head> <body> <h1>{sn_news_title}  containing  {username}</h1> <p>&copy;  {current_date  format="%Y"}</p> </body> </html>
49. <html> <head>    <title>{sn_{segment_1}_title}  -­‐  EE  Outsider</title> </head> <body> <h1>{sn_news_title}  containing  kennymeyers</h1> <p>&copy;  {current_date  format="%Y"}</p> </body> </html>
50. Variables Example 2
51. {sn_header} {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {sn_page} {gv_footer}
52. Snippets {sn_header} {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {sn_page} {gv_footer}
53. <html> <head>    <title>{gv_{segment_1}_title}</title> </head> <body> {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {exp:channel:entries  channel="{segment_1}"    limit="{pre_limit}"}        <h2>{title}</h2>        {pre_body} {/exp:channel:entries} {gv_footer}
54. Segment vars <html> <head>    <title>{gv_{segment_1}_title}</title> </head> <body> {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {exp:channel:entries  channel="{segment_1}"    limit="{pre_limit}"}        <h2>{title}</h2>        {pre_body} {/exp:channel:entries} {gv_footer}
55. <html> <head>    <title>{gv_news_title}</title> </head> <body> {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {exp:channel:entries  channel="news"    limit="{pre_limit}"}        <h2>{title}</h2>        {pre_body} {/exp:channel:entries} {gv_footer}
56. Preload Replace vars <html> <head>    <title>{gv_news_title}</title> </head> <body> {preload_replace:pre_limit="1"} {preload_replace:pre_body="{cf_summary}"} {exp:channel:entries  channel="news"    limit="{pre_limit}"}        <h2>{title}</h2>        {pre_body} {/exp:channel:entries} {gv_footer}
57. <html> <head>    <title>{gv_news_title}</title> </head> <body> {exp:channel:entries  channel="news"  limit="1"}    <h2>{title}</h2>    {cf_summary} {/exp:channel:entries} {gv_footer}
58. Tags & Local vars <html> <head>    <title>{gv_news_title}</title> </head> <body> {exp:channel:entries  channel="news"  limit="1"}    <h2>{title}</h2>    {cf_summary} {/exp:channel:entries} {gv_footer}
59. <html> <head>    <title>{gv_news_title}</title> </head> <body>    <h2>Missing:  Kenny  Meyers</h2>    <p>Last  seen  at  Pier  39  San  Francisco,          hanging  out  with  some  friends.</p> {gv_footer}
60. User Defined Global vars <html> <head>    <title>{gv_news_title}</title> </head> <body>    <h2>Missing:  Kenny  Meyers</h2>    <p>Last  seen  at  Pier  39  San  Francisco,          hanging  out  with  some  friends.</p> {gv_footer}
61. <html> <head>    <title>The  News</title> </head> <body>    <h2>Missing:  Kenny  Meyers</h2>    <p>Last  seen  at  Pier  39  San  Francisco,          hanging  out  with  some  friends.</p> <p>&copy;  {site_name}</p> </body> </html>
62. Standard Global vars <html> <head>    <title>The  News</title> </head> <body>    <h2>Missing:  Kenny  Meyers</h2>    <p>Last  seen  at  Pier  39  San  Francisco,          hanging  out  with  some  friends.</p> <p>&copy;  {site_name}</p> </body> </html>
63. <html> <head>    <title>The  News</title> </head> <body>    <h2>Missing:  Kenny  Meyers</h2>    <p>Last  seen  at  Pier  39  San  Francisco,          hanging  out  with  some  friends.</p> <p>&copy;  EE  Outsider</p> </body> </html>
65. Conditionals
66. Conditional Types •Simple •Advanced •Special
67. Simple Conditionals •Only work with early parsed variables * •Only work with one operand •Only work without if:else statement •If so, are parsed before tags *) Except Preload Replace variables
68. Advanced Conditionals •All other conditionals * •Converted to PHP, then evaluated •Are parsed after tags *) Except special conditionals
69. PUT CODE IN CONDITIONALS STILL PARSES ALL THE TAGS
70. Special Conditionals •Parsed during and by tags •For example: • {if no_results} {/if} • {if next_page} {/if} • etc. •But most conditionals in tags are actually advanced conditionals
71. simple  conditionals {exp:tags}  special  conditionals  {/exp:tags} advanced  conditionals All Conditionals
72. Conditionals Example 1
73. {if  segment_3  ==  'by-­‐category'}    {exp:channel:categories  channel="bars"}            <a  href="#">{category_name}</a>    {/exp:channel:categories} {if:else}  {exp:channel:entries        channel="bars{if  logged_in}|foos{/if}"}            <h2>{title}</h2>            {if  no_results}Nothing  found!{/if}    {/exp:channel:entries} {/if}
74. Simple conditionals {if  segment_3  ==  'by-­‐category'}    {exp:channel:categories  channel="bars"}            <a  href="#">{category_name}</a>    {/exp:channel:categories} {if:else}  {exp:channel:entries        channel="bars{if  logged_in}|foos{/if}"}            <h2>{title}</h2>            {if  no_results}Nothing  found!{/if}    {/exp:channel:entries} {/if}    
75. {if  segment_3  ==  'by-­‐category'}    {exp:channel:categories  channel="bars"}            <a  href="#">{category_name}</a>    {/exp:channel:categories} {if:else}  {exp:channel:entries        channel="bars{if  logged_in}|foos{/if}"}            <h2>{title}</h2>            {if  no_results}Nothing  found!{/if}    {/exp:channel:entries} {/if}
76. Tags & Special conditionals {if  segment_3  ==  'by-­‐category'}    {exp:channel:categories  channel="bars"}            <a  href="#">{category_name}</a>    {/exp:channel:categories} {if:else}  {exp:channel:entries        channel="bars{if  logged_in}|foos{/if}"}            <h2>{title}</h2>            {if  no_results}Nothing  found!{/if}    {/exp:channel:entries} {/if}
77. {if  segment_3  ==  'by-­‐category'}            <a  href="#">Brooklyn</a>            <a  href="#">Manhattan</a>            <a  href="#">Queens</a> {if:else}            Nothing  found! {/if}
78. Advanced conditionals {if  segment_3  ==  'by-­‐category'}            <a  href="#">Brooklyn</a>            <a  href="#">Manhattan</a>            <a  href="#">Queens</a> {if:else}            Nothing  found! {/if}
79.            Nothing  found!
80. Conditionals Example 2
81. {if  logged_in}    {exp:channel:entries  channel="bars"        {if  segment_3  !=  'all'}limit="2"{/if}}            <h2>{title}</h2>            {if  cf_bar_is_awesome  ==  'y'}                This  bar  is  awesome!            {/if}    {/exp:channel:entries} {/if} {if  sn_show_foos  ==  'y'}    {exp:channel:entries  channel="foos"}        <h3>{title}</h3>        {if  no_results}No  foos  found!{/if}    {/exp:channel:entries} {/if}
82. Simple conditionals {if  logged_in}    {exp:channel:entries  channel="bars"        {if  segment_3  !=  'all'}limit="2"{/if}}            <h2>{title}</h2>            {if  cf_bar_is_awesome  ==  'y'}                This  bar  is  awesome!            {/if}    {/exp:channel:entries} {/if} {if  sn_show_foos  ==  'y'}    {exp:channel:entries  channel="foos"}        <h3>{title}</h3>        {if  no_results}No  foos  found!{/if}    {/exp:channel:entries} {/if}
83. {if  logged_in}    {exp:channel:entries  channel="bars"        limit="2"}            <h2>{title}</h2>            {if  cf_bar_is_awesome  ==  'y'}                This  bar  is  awesome!            {/if}    {/exp:channel:entries} {/if}    {exp:channel:entries  channel="foos"}        <h3>{title}</h3>        {if  no_results}No  foos  found!{/if}    {/exp:channel:entries}
84. Tags & Special conditionals {if  logged_in}    {exp:channel:entries  channel="bars"        limit="2"}            <h2>{title}</h2>            {if  cf_bar_is_awesome  ==  'y'}                This  bar  is  awesome!            {/if}    {/exp:channel:entries} {/if}    {exp:channel:entries  channel="foos"}        <h3>{title}</h3>        {if  no_results}No  foos  found!{/if}    {/exp:channel:entries}
85. {if  logged_in}            <h2>Bar  One</h2>            {if  'n'  ==  'y'}                This  bar  is  awesome!            {/if}            <h2>Bar  Two</h2>            {if  'y'  ==  'y'}                This  bar  is  awesome!            {/if} {/if}        <h3>Foo  One</h3>        <h3>Foo  Two</h3>        <h3>Foo  Three</h3>
86. Advanced conditionals {if  logged_in}            <h2>Bar  One</h2>            {if  'n'  ==  'y'}                This  bar  is  awesome!            {/if}            <h2>Bar  Two</h2>            {if  'y'  ==  'y'}                This  bar  is  awesome!            {/if} {/if}        <h3>Foo  One</h3>        <h3>Foo  Two</h3>        <h3>Foo  Three</h3>
87.            <h2>Bar  One</h2>            <h2>Bar  Two</h2>                This  bar  is  awesome!        <h3>Foo  One</h3>        <h3>Foo  Two</h3>        <h3>Foo  Three</h3>
88. Tags
89. Tag Types •Module or Plugin •Single or Pair
90. NOT SURE IF THAT'S A MODULE TAG OR A PLUGIN TAG
91. Module Tags •Parsed from the document root inwards •Repeated until no tags are left
92. Plugin Tags •Look inside for other tags first •If found, that tag is parsed first •Except if it's a plugin tag, then see previous •Cancel this behaviour with parse="inward"
93. Tags Example 1
94. {exp:channel:entries  channel="feeds"  limit="3"}    <h2>{title}</h2>    {exp:magpie  url="{feed_url}"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie} {/exp:channel:entries}
95. {exp:channel:entries  channel="feeds"  limit="3"}    <h2>{title}</h2>    {exp:magpie  url="{feed_url}"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie} {/exp:channel:entries}
96.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}
97.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}
98.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}
99.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"}        {items}            <h3>{magpie:title}</h3>            {magpie:content}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"}        {items}            <h3>{magpie:title}</h3>            {magpie:content}        {/items}    {/exp:magpie}
100.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"}        {items}            <h3>{magpie:title}</h3>            {magpie:content}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"}        {items}            <h3>{magpie:title}</h3>            {magpie:content}        {/items}    {/exp:magpie}
101.    <h2>First  title</h2>            <h3>Title  1.1</h3>            <p>Lorem  ipsum  <a  href="#">dolor</a>  sit  amet</p>            <h3>Title  1.2</h3>            <p>The  lazy  dog  jumped  over  the  <em>fox</em></p>    <h2>Second  title</h2>            <h3>Title  2.1</h3>            <embeds  and  malicious  code>            <h3>Title  2.2</h3>            <blinks  and  marquees>
102. Tags Example 2
103. {exp:channel:entries  channel="feeds"  limit="3"}    <h2>{title}</h2>    {exp:magpie  url="{feed_url}"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie} {/exp:channel:entries}
104. {exp:channel:entries  channel="feeds"  limit="3"}    <h2>{title}</h2>    {exp:magpie  url="{feed_url}"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie} {/exp:channel:entries}
105.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}
106.    <h2>First  title</h2>    {exp:magpie  url="http://one.com/rss"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}    <h2>Second  title</h2>    {exp:magpie  url="http://two.com/rss"  parse="inward"}        {items}            <h3>{magpie:title}</h3>            {exp:strip_html}{magpie:content}{/exp:strip_html}        {/items}    {/exp:magpie}
107.    <h2>First  title</h2>            <h3>Title  1.1</h3>            {exp:strip_html}<p>Lorem  ipsum  <a  href="#">            dolor</a>  sit  amet</p>{/exp:strip_html}            <h3>Title  1.2</h3>            {exp:strip_html}<p>The  lazy  dog  jumped  over            the  <em>fox</em></p>{/exp:strip_html}    <h2>Second  title</h2>            <h3>Title  2.1</h3>            {exp:strip_html}<embeds>{/exp:strip_html}            <h3>Title  2.2</h3>            {exp:strip_html}<marquees>{/exp:strip_html}
108.    <h2>First  title</h2>            <h3>Title  1.1</h3>            {exp:strip_html}<p>Lorem  ipsum  <a  href="#">            dolor</a>  sit  amet</p>{/exp:strip_html}            <h3>Title  1.2</h3>            {exp:strip_html}<p>The  lazy  dog  jumped  over            the  <em>fox</em></p>{/exp:strip_html}    <h2>Second  title</h2>            <h3>Title  2.1</h3>            {exp:strip_html}<embeds>{/exp:strip_html}            <h3>Title  2.2</h3>            {exp:strip_html}<marquees>{/exp:strip_html}
109.    <h2>First  title</h2>            <h3>Title  1.1</h3>            Lorem  ipsum  dolor  sit  amet            <h3>Title  1.2</h3>            The  lazy  dog  jumped  over  the  fox    <h2>Second  title</h2>            <h3>Title  2.1</h3>            ...            <h3>Title  2.2</h3>            ...
110. A Parse Order Pro •...can identify markers •...knows when they are parsed •...knows how to nest them •...and will always...
111. PARSE ALL THE THINGS! gotolow.com/parse-order
112. Questions?
113. Thank You! gotolow.com @low