WebSVN – wimsdev – Diff – /trunk/wims/public_html/modules/help/wimsdoc.en/variables.phtml



<p>
A variable may be defined or modified in a variable processing file, or by
the commands
$(ref1)cmdlist_let_&+cmd_choose=all$(ref2)cmdlist_let_">!let</a> and
$(ref1)cmdlist_default_&+cmd_choose=all$(ref2)cmdlist_default_">!default</a>.
</p><p>
Variable names can contain any alphanumeric character, as well as the
underscore character $(emph)_$emphend. There is a limit to the length of
variable names, and a limit to the length of values. (Limits depending on
server configuration.)
</p><p>
Variable substitution can be done anywhere in a variable processing file or
a phtml file (even in the name field of a variable definition
line). A word preceeded by the character $emph$$$emphend
is considered to be a variable name, and will be replaced by its value when
the line containing it is processed.
</p><p>
Special rules of variable substitution:
</p>
<ul>
 <li>If the character $emph$$$emphend is followed by a space, it will be
  discarded.
 </li><li>The string $emph$$$$$emphend is replaced by a single $emph$$$emphend.
 </li><li>If the character $emph$$$emphend is followed by the left parenthesis
  $emph($emphend, the matching $emph)$emphend will be located, the content
  of the pair of parentheses substituted. The result of the substitution
  will then be used as the name of variable, and finally the whole thing
  will be replaced by the value of the last variable. This allows nested
  substitutions, as well as substitution of a variable which is followed

  <p>
  Array addressing: if the variable $(emph)l$emphend contains a
  comma-separated list $(emph)a,b,c,d,e$emphend, then the string
  <tt>$$(i[3])</tt> gives <tt>c</tt> after substitution, and
  <tt>$$(i[2 to 4])</tt> tives <tt>b,c,d</tt>, etc.
  </p><p>
  Two-dimensional array addressing is also available: if
  <pre>$$M=x,y,z;a,b,c</pre>
  (a 2x3 matrix), then
  <pre>$$(M[1;3,2])=z,y</pre>
  </li><li>If the character $emph$$$emphend is followed by the left bracket
  $emph[$emphend, the matching $emph]$emphend will be located, the content
  of the pair of brackets substituted then evaluated to a real number value whose
  precision depends on the value of $emph print_precision$emphend.
  This value will replace the whole thing
  together with the leading $emph$$$emphend. <br/>

  $(emph)a1$emphend has value $(emph)3$emphend and <br/>
  $(emph)a2$emphend has value $(emph)pi$emphend, <br/>
  then the string<pre>
  $$(a$$[$$i-1])*x+$$(a$$[$$i-2])</pre>will become<pre>
  pi*x+3</pre>after substitution.
 </li><li>If the value of a variable being substituted contains the character
  $emph$$$emphend, this value will again be substituted, until no more
  substitution is needed. The server has a built-in limit of nested
  substitutions; infinite nested substitions will violate this limit and
  generate an error message.
  </li>
</ul>
 
<p><hr/></p>
<h4>Reserved variable names</h4>
 
The following names are reserved for their special meanings. They should not be
used for internal needs of any module.
 
<ul>
 <li>Do not use variables with names consisting only of numbers. They are
  reserved for future enhancements of the language.
 </li><li>Variables named
  !for i in cmd,module,session,lang,special_parm,user,useropts,worksheet
   $emph$i$emphend,
  !next i
  are reserved for special parameter passing by the user. A module's variable
  processing files or phtml files can read but cannot set them. <br/>
  Refer to the section $emph$title_structure$emphend for the meaning of
  these variables.
 </li><li>The variable $emph no_name$emphend has a special use: <br/>
  Parameters in the user query string with no name (for example when the
  coordinate of a mappable image is passed this way to the http server) will
  be registered under this variable. For this reason, it should not be used
  for other purposes.
 </li><li>All variable names starting with $emph wims_$emphend will have special
  meanings for wims server. A module should read or write them only for the
  special meanings they are designed for.
 </li><li>Variable names starting with $emph m_$emphend are reserved for inline
  mathematical fonts. The module programmer may redefine them, but then their
  original meaning will be lost.
 </li><li>The variable $emph module_dir$emphend has a value preset to the directory
  of the current module (with respect to the public home directory of the
  server). This value is usually $emph $$module_dir=module/$$module $emphend
  (but may vary with the config of the installation).
 </li><li>Variable names starting with $emph module_$emphend will have special
  meanings: they are used to hold variables defined in the module's INDEX
  file. Currently implemented variables:
 
  $table_header
  $table_tr<th> Variables</th><th>Meaning</th></tr>

   $table_tr<td>$emph module_domain$emphend<td>algebra, analysis, geometry, ...
   $table_tr<td>$emph module_keywords$emphend<td>keywords, to be placed in the html header
   $table_tr<td>$emph module_scoring$emphend<td>= yes if the module gives scores according to wims standard
   $table_tr<td>$emph module_data$emphend<td>address of datamodule
 
  </table>
  Also, variables $emph module_has_intro$emphend,
  $emph module_has_help$emphend and
  $emph module_has_about$emphend
  have value "yes" if the module's directory contains the respective
  .phtml file. These variables are used in the command <tt>!homeref</tt>.
 </li><li>Certain environment variables setup by httpd are readable by wims
  modules under names starting with $emph httpd_$emphend. For example, the
  environment variable $emph REMOTE_HOST$emphend becomes
  $emph httpd_REMOTE_HOST$emphend under wims. <br/>
  Please refer to httpd protocol specifications for details of such variables.
 </li><li>All variable names starting with $emph ins_$emphend, $emph
  insplot_$emphend, $emph instex_$emphend will have special meanings for the
  corresponding dynamic insertion engines. A module should read or write them
  only for the special meanings they are designed for.
 </li><li>If your module uses an external package (e.g. $emph pari$emphend),
  variable names starting with the name of the interface to that external
  package followed by $emph _$emphend will have special meanings for that
  interface, and should be reserved for that purpose.
  </li>
</ul>
 

Subversion Repositories wimsdev

(root)/trunk/wims/public_html/modules/help/wimsdoc.en/variables.phtml – Rev 5766 → 5798

Rev 5766		Rev 5798
Line 7...		Line 7...
7	<p>	7	<p>
8	A variable may be defined or modified in a variable processing file, or by	8	A variable may be defined or modified in a variable processing file, or by
9	the commands	9	the commands
10	$(ref1)cmdlist_let_&+cmd_choose=all$(ref2)cmdlist_let_">!let</a> and	10	$(ref1)cmdlist_let_&+cmd_choose=all$(ref2)cmdlist_let_">!let</a> and
11	$(ref1)cmdlist_default_&+cmd_choose=all$(ref2)cmdlist_default_">!default</a>.	11	$(ref1)cmdlist_default_&+cmd_choose=all$(ref2)cmdlist_default_">!default</a>.
12	<p>	12	</p><p>
13	Variable names can contain any alphanumeric character, as well as the	13	Variable names can contain any alphanumeric character, as well as the
14	underscore character $(emph)_$emphend. There is a limit to the length of	14	underscore character $(emph)_$emphend. There is a limit to the length of
15	variable names, and a limit to the length of values. (Limits depending on	15	variable names, and a limit to the length of values. (Limits depending on
16	server configuration.)	16	server configuration.)
17	<p>	17	</p><p>
18	Variable substitution can be done anywhere in a variable processing file or	18	Variable substitution can be done anywhere in a variable processing file or
19	a phtml file (even in the name field of a variable definition	19	a phtml file (even in the name field of a variable definition
20	line). A word preceeded by the character $emph$$$emphend	20	line). A word preceeded by the character $emph$$$emphend
21	is considered to be a variable name, and will be replaced by its value when	21	is considered to be a variable name, and will be replaced by its value when
22	the line containing it is processed.	22	the line containing it is processed.
23	<p>	23	</p><p>
24	Special rules of variable substitution:	24	Special rules of variable substitution:
-		25	</p>
25	<ul>	26	<ul>
26	<li>If the character $emph$$$emphend is followed by a space, it will be	27	<li>If the character $emph$$$emphend is followed by a space, it will be
27	discarded.	28	discarded.
28	<li>The string $emph$$$$$emphend is replaced by a single $emph$$$emphend.	29	</li><li>The string $emph$$$$$emphend is replaced by a single $emph$$$emphend.
29	<li>If the character $emph$$$emphend is followed by the left parenthesis	30	</li><li>If the character $emph$$$emphend is followed by the left parenthesis
30	$emph($emphend, the matching $emph)$emphend will be located, the content	31	$emph($emphend, the matching $emph)$emphend will be located, the content
31	of the pair of parentheses substituted. The result of the substitution	32	of the pair of parentheses substituted. The result of the substitution
32	will then be used as the name of variable, and finally the whole thing	33	will then be used as the name of variable, and finally the whole thing
33	will be replaced by the value of the last variable. This allows nested	34	will be replaced by the value of the last variable. This allows nested
34	substitutions, as well as substitution of a variable which is followed	35	substitutions, as well as substitution of a variable which is followed
Line 41...		Line 42...
41	<p>	42	<p>
42	Array addressing: if the variable $(emph)l$emphend contains a	43	Array addressing: if the variable $(emph)l$emphend contains a
43	comma-separated list $(emph)a,b,c,d,e$emphend, then the string	44	comma-separated list $(emph)a,b,c,d,e$emphend, then the string
44	<tt>$$(i[3])</tt> gives <tt>c</tt> after substitution, and	45	<tt>$$(i[3])</tt> gives <tt>c</tt> after substitution, and
45	<tt>$$(i[2 to 4])</tt> tives <tt>b,c,d</tt>, etc.	46	<tt>$$(i[2 to 4])</tt> tives <tt>b,c,d</tt>, etc.
46	<p>	47	</p><p>
47	Two-dimensional array addressing is also available: if	48	Two-dimensional array addressing is also available: if
48	<pre>$$M=x,y,z;a,b,c</pre>	49	<pre>$$M=x,y,z;a,b,c</pre>
49	(a 2x3 matrix), then	50	(a 2x3 matrix), then
50	<pre>$$(M[1;3,2])=z,y</pre>	51	<pre>$$(M[1;3,2])=z,y</pre>
51	<li>If the character $emph$$$emphend is followed by the left bracket	52	</li><li>If the character $emph$$$emphend is followed by the left bracket
52	$emph[$emphend, the matching $emph]$emphend will be located, the content	53	$emph[$emphend, the matching $emph]$emphend will be located, the content
53	of the pair of brackets substituted then evaluated to a real number value whose	54	of the pair of brackets substituted then evaluated to a real number value whose
54	precision depends on the value of $emph print_precision$emphend.	55	precision depends on the value of $emph print_precision$emphend.
55	This value will replace the whole thing	56	This value will replace the whole thing
56	together with the leading $emph$$$emphend. <br/>	57	together with the leading $emph$$$emphend. <br/>
Line 60...		Line 61...
60	$(emph)a1$emphend has value $(emph)3$emphend and <br/>	61	$(emph)a1$emphend has value $(emph)3$emphend and <br/>
61	$(emph)a2$emphend has value $(emph)pi$emphend, <br/>	62	$(emph)a2$emphend has value $(emph)pi$emphend, <br/>
62	then the string<pre>	63	then the string<pre>
63	$$(a$$[$$i-1])*x+$$(a$$[$$i-2])</pre>will become<pre>	64	$$(a$$[$$i-1])*x+$$(a$$[$$i-2])</pre>will become<pre>
64	pi*x+3</pre>after substitution.	65	pi*x+3</pre>after substitution.
65	<li>If the value of a variable being substituted contains the character	66	</li><li>If the value of a variable being substituted contains the character
66	$emph$$$emphend, this value will again be substituted, until no more	67	$emph$$$emphend, this value will again be substituted, until no more
67	substitution is needed. The server has a built-in limit of nested	68	substitution is needed. The server has a built-in limit of nested
68	substitutions; infinite nested substitions will violate this limit and	69	substitutions; infinite nested substitions will violate this limit and
69	generate an error message.	70	generate an error message.
-		71	</li>
70	</ul>	72	</ul>
71		73
-		74	<p><hr/></p>
72	~~<hr/>~~<h4>Reserved variable names</h4>	75	<h4>Reserved variable names</h4>
73		76
74	The following names are reserved for their special meanings. They should not be	77	The following names are reserved for their special meanings. They should not be
75	used for internal needs of any module.	78	used for internal needs of any module.
76		79
77	<ul>	80	<ul>
78	<li>Do not use variables with names consisting only of numbers. They are	81	<li>Do not use variables with names consisting only of numbers. They are
79	reserved for future enhancements of the language.	82	reserved for future enhancements of the language.
80	<li>Variables named	83	</li><li>Variables named
81	!for i in cmd,module,session,lang,special_parm,user,useropts,worksheet	84	!for i in cmd,module,session,lang,special_parm,user,useropts,worksheet
82	$emph$i$emphend,	85	$emph$i$emphend,
83	!next i	86	!next i
84	are reserved for special parameter passing by the user. A module's variable	87	are reserved for special parameter passing by the user. A module's variable
85	processing files or phtml files can read but cannot set them. <br/>	88	processing files or phtml files can read but cannot set them. <br/>
86	Refer to the section $emph$title_structure$emphend for the meaning of	89	Refer to the section $emph$title_structure$emphend for the meaning of
87	these variables.	90	these variables.
88	<li>The variable $emph no_name$emphend has a special use: <br/>	91	</li><li>The variable $emph no_name$emphend has a special use: <br/>
89	Parameters in the user query string with no name (for example when the	92	Parameters in the user query string with no name (for example when the
90	coordinate of a mappable image is passed this way to the http server) will	93	coordinate of a mappable image is passed this way to the http server) will
91	be registered under this variable. For this reason, it should not be used	94	be registered under this variable. For this reason, it should not be used
92	for other purposes.	95	for other purposes.
93	<li>All variable names starting with $emph wims_$emphend will have special	96	</li><li>All variable names starting with $emph wims_$emphend will have special
94	meanings for wims server. A module should read or write them only for the	97	meanings for wims server. A module should read or write them only for the
95	special meanings they are designed for.	98	special meanings they are designed for.
96	<li>Variable names starting with $emph m_$emphend are reserved for inline	99	</li><li>Variable names starting with $emph m_$emphend are reserved for inline
97	mathematical fonts. The module programmer may redefine them, but then their	100	mathematical fonts. The module programmer may redefine them, but then their
98	original meaning will be lost.	101	original meaning will be lost.
99	<li>The variable $emph module_dir$emphend has a value preset to the directory	102	</li><li>The variable $emph module_dir$emphend has a value preset to the directory
100	of the current module (with respect to the public home directory of the	103	of the current module (with respect to the public home directory of the
101	server). This value is usually $emph $$module_dir=module/$$module $emphend	104	server). This value is usually $emph $$module_dir=module/$$module $emphend
102	(but may vary with the config of the installation).	105	(but may vary with the config of the installation).
103	<li>Variable names starting with $emph module_$emphend will have special	106	</li><li>Variable names starting with $emph module_$emphend will have special
104	meanings: they are used to hold variables defined in the module's INDEX	107	meanings: they are used to hold variables defined in the module's INDEX
105	file. Currently implemented variables:	108	file. Currently implemented variables:
106		109
107	$table_header	110	$table_header
108	$table_tr<th> Variables</th><th>Meaning</th></tr>	111	$table_tr<th> Variables</th><th>Meaning</th></tr>
Line 123...		Line 126...
123	$table_tr<td>$emph module_domain$emphend<td>algebra, analysis, geometry, ...	126	$table_tr<td>$emph module_domain$emphend<td>algebra, analysis, geometry, ...
124	$table_tr<td>$emph module_keywords$emphend<td>keywords, to be placed in the html header	127	$table_tr<td>$emph module_keywords$emphend<td>keywords, to be placed in the html header
125	$table_tr<td>$emph module_scoring$emphend<td>= yes if the module gives scores according to wims standard	128	$table_tr<td>$emph module_scoring$emphend<td>= yes if the module gives scores according to wims standard
126	$table_tr<td>$emph module_data$emphend<td>address of datamodule	129	$table_tr<td>$emph module_data$emphend<td>address of datamodule
127		130
128	</table~~></center~~>	131	</table>
129	Also, variables $emph module_has_intro$emphend,	132	Also, variables $emph module_has_intro$emphend,
130	$emph module_has_help$emphend and	133	$emph module_has_help$emphend and
131	$emph module_has_about$emphend	134	$emph module_has_about$emphend
132	have value "yes" if the module's directory contains the respective	135	have value "yes" if the module's directory contains the respective
133	.phtml file. These variables are used in the command <tt>!homeref</tt>.	136	.phtml file. These variables are used in the command <tt>!homeref</tt>.
134	<li>Certain environment variables setup by httpd are readable by wims	137	</li><li>Certain environment variables setup by httpd are readable by wims
135	modules under names starting with $emph httpd_$emphend. For example, the	138	modules under names starting with $emph httpd_$emphend. For example, the
136	environment variable $emph REMOTE_HOST$emphend becomes	139	environment variable $emph REMOTE_HOST$emphend becomes
137	$emph httpd_REMOTE_HOST$emphend under wims. <br/>	140	$emph httpd_REMOTE_HOST$emphend under wims. <br/>
138	Please refer to httpd protocol specifications for details of such variables.	141	Please refer to httpd protocol specifications for details of such variables.
139	<li>All variable names starting with $emph ins_$emphend, $emph	142	</li><li>All variable names starting with $emph ins_$emphend, $emph
140	insplot_$emphend, $emph instex_$emphend will have special meanings for the	143	insplot_$emphend, $emph instex_$emphend will have special meanings for the
141	corresponding dynamic insertion engines. A module should read or write them	144	corresponding dynamic insertion engines. A module should read or write them
142	only for the special meanings they are designed for.	145	only for the special meanings they are designed for.
143	<li>If your module uses an external package (e.g. $emph pari$emphend),	146	</li><li>If your module uses an external package (e.g. $emph pari$emphend),
144	variable names starting with the name of the interface to that external	147	variable names starting with the name of the interface to that external
145	package followed by $emph _$emphend will have special meanings for that	148	package followed by $emph _$emphend will have special meanings for that
146	interface, and should be reserved for that purpose.	149	interface, and should be reserved for that purpose.
-		150	</li>
147	</ul>	151	</ul>
148		152