3 # Copyright (C) 2008,2009 Joshua Grams <josh@qualdan.com>
5 # This program is free software: you can redistribute it and/or modify
6 # it under the terms of the GNU General Public License as published by
7 # the Free Software Foundation, either version 3 of the License, or
8 # (at your option) any later version.
10 # This program is distributed in the hope that it will be useful,
11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 # GNU General Public License for more details.
15 # You should have received a copy of the GNU General Public License
16 # along with this program. If not, see <http://www.gnu.org/licenses/>.
19 # This is a simple template-handling system. You pass it a big data
20 # structure with key/value pairs, and a template string to fill out.
22 # Within a template, it recognizes tags of the form ~name [arg...]~,
23 # optionally wrapped in HTML comments (which will be removed along with
24 # the tag markers when the template is filled out).
26 # { and } as the final argument mark those tags as being the start and
27 # end of a sub-template (for optional or repeated sections). All other
28 # tags represent slots to be directly filled by data values. On a }
29 # tag, the name is optional, but must match the corresponding { tag if
32 # For a value tag, arguments represent encodings to be applied
33 # successively. For instance, ~foo html~ will encode it to be safe in
34 # HTML ('&' to '&', '<' to '<', and so on).
36 # { tags can take one argument, which will call the corresponding
37 # tem_auto_* function to munge the data, automating certain common use
38 # cases. See the comments on the tem_auto functions for more details.
40 require_once('code/wfpl/encode.php');
41 require_once('code/wfpl/file.php');
42 require_once('code/wfpl/misc.php');
48 function template($template, $data) {
49 return fill_template(parse_template($template), $data);
52 function template_file($filename, $data) {
53 return fill_template(parse_template_file($filename), $data);
56 function &parse_template_file($filename) {
57 return parse_template(file_get_contents($filename));
60 # We parse the template string into a tree of strings and sub-templates.
61 # A template is a hash with a name string, a pieces array, and possibly
64 function &parse_template($string) {
66 $tem['pieces'] = array();
67 $matches = preg_split('/(<!--)?(~[^~]*~)(?(1)-->)/', preg_replace('/<!--(~[^~]*~)-->/', '$1', $string), -1, PREG_SPLIT_DELIM_CAPTURE | PREG_SPLIT_NO_EMPTY);
68 foreach($matches as $match) {
69 if($match == '~~') $match = '~';
70 if(substr($match,0,1) == '~' and strlen($match) > 2) {
71 $args = explode(' ', substr($match,1,-1));
73 if(count($args) == 1 and $args[0] == '}') $name = '';
74 else $name = array_shift($args);
76 if(last($args) == '{') { # open block
77 array_pop($args); # drop '{'
78 $tem =& tem_push($tem); # create a new sub-template
79 $tem['parent']['pieces'][] =& $tem; # as a piece of the parent
81 $tem['pieces'] = array();
83 } elseif(last($args) == '}') { # close block
84 array_pop($args); # drop '}'
86 if($name && $name != $cur) {
87 die("Invalid template: tried to close '$name', but '$cur' is current.");
89 $tem =& $tem['parent'];
91 $tem['pieces'][] = array('name' => $name, 'args' => $args);
93 } else { # static string
94 $tem['pieces'][] = $match;
100 function fill_template($template, &$data, &$context = NULL) {
101 $context =& tem_push($context);
102 $context['data'] =& $data;
104 foreach($template['pieces'] as $tem) {
105 if(is_string($tem)) $output .= $tem;
106 elseif($tem['pieces']) { # sub-template
107 $rows =& tem_row_data($tem, $context);
108 $context['rows'] =& $rows;
109 foreach($rows as $key => &$row) {
110 $context['cur'] = $key;
111 $output .= fill_template($tem, $row, $context);
114 $output .= tem_encoded_data($tem, $context);
117 $context =& $context['parent'];
126 # To track our position in the template and in the data, we use a linked
127 # stack structure. Each node is a hash with a reference to the parent
128 # node along with whatever other data you want to add. For each stack,
129 # you simply keep a variable with a reference to the top element. Then
130 # the push and pop operations are:
132 # $top =& tem_push($top);
133 # $top =& $top['parent'];
135 function &tem_push(&$stack = NULL) {
136 static $refs = array();
138 # Since a PHP reference is *not* a pointer to data, but a pointer to
139 # a variable (or array slot), we *have* to first put the new node in
140 # $refs, and then reference it from $new.
143 $new =& $refs[count($refs)-1];
144 if($stack) $new['parent'] =& $stack;
148 # To fill out a template, we do a depth-first traversal of the template
149 # tree, replacing all tags with the data values.
151 # The data starts out as a nested set of key/value pairs, where the
154 # a string to fill a value slot
155 # a hash to fill one instance of a sub-template
156 # an array of hashes to fill multiple instances of a sub-template
158 # The middle form will be converted to the last form as we use it.
160 function tem_data_as_rows($value, $key) {
161 if(is_array($value)) {
163 if(array_key_exists(0, $value)) {
164 if(is_array($value[0])) return $value; # already array of hashes.
165 else return columnize($value, $key);
166 # key/value pairs -- expand sub-template once.
167 } else return array($value);
168 } elseif($value || $value === 0 || $value === '0' || $value === '') {
169 # value -- expand sub-template once using only parent values
170 return array(array());
172 # empty value -- don't expand sub-template
177 # To look up a key, we check each namespace (starting with the
178 # innermost one) until a value is found.
180 function tem_data_scope($key, $context) {
181 static $refs = array();
185 if(array_key_exists($key, $scope['data'])) {
188 } while($scope = $scope['parent']);
190 # not found; return empty scope.
193 $ret['parent'] =& $context;
194 $ret['data'] =& last($refs);
198 function tem_get_data($key, $context) {
199 $scope = tem_data_scope($key, $context);
200 if($scope) return $scope['data'][$key];
203 # Return the value for a tag as a set of rows to fill a sub-template.
204 # If $tag has an arg, call the tem_auto function to munge the data.
205 function &tem_row_data($tem, $context)
208 $scope = tem_data_scope($key, $context);
210 if(count($tem['args'])) {
211 $auto_func = "tem_auto_" . $tem['args'][0];
212 function_exists($auto_func)
213 or die("ERROR: template auto function '$auto_func' not found.<br>\n");
215 if($auto_func) $value = $auto_func($scope['data'][$key], $key, $scope);
216 else $value = $scope['data'][$key];
218 $rows = tem_data_as_rows($value, $key);
219 if(is_array($value)) $scope['data'][$key] = $rows;
224 # Return the value for a tag as an encoded string.
225 function tem_encoded_data($tag, $context)
228 $value = tem_get_data($key, $context);
229 foreach($tag['args'] as $encoding) {
230 $func = "enc_$encoding";
231 if(function_exists($func)) $value = $func($value, $key);
232 else die("ERROR: encoder function '$func' not found.<br>\n");
238 function is_sub_template(&$piece) {
239 return is_array($piece) and $piece['pieces'];
242 function is_value_slot(&$piece) {
243 return is_array($piece) and !$piece['pieces'];
246 # Return a hash containing the top-level sub-templates of tem.
247 function top_sub_templates($tem, $is_sub = 'is_sub_template') {
248 function_exists($is_sub) or die("no such function '$is_sub'.");
250 foreach($tem['pieces'] as $piece) {
251 if($is_sub($piece)) {
252 $subs[$piece['name']] = $piece;
258 # merge $subs (sub_templates) into variables in $main (template)
259 function merge_sub_templates(&$main, &$subs) {
260 foreach($main['pieces'] as &$piece) {
261 if(is_array($piece)) { # not just text
262 if($piece['pieces']) {
263 # a sub-template in main
264 merge_sub_templates($piece, $subs);
266 # a value-slot in main
267 $sub = $subs[$piece['name']];
268 if($sub and $sub['args'][0] != 'hide') {
269 $piece = $subs[$piece['name']];
270 $piece['parent'] =& $main;
278 # Replace values in $main with top-level templates from $tem.
279 function merge_templates(&$main, &$tem) {
280 $subs = top_sub_templates($tem);
282 merge_sub_templates($main, $subs);
290 # If a { tag has an argument, the corresponding tem_auto function is called.
291 # This allows it to mangle the data to automate some common cases.
293 # 'sep' (separator) sections will be shown for all but the last parent row.
298 # <!--~separator sep {~--><hr><!--~}~-->
302 function tem_auto_sep(&$value, $key, $context) {
303 $rows =& $context['parent']['parent'];
304 if($rows['cur'] != count($rows['rows'])-1) # last row?
305 return true; # show once
308 # auto-show once, only when this is the first row of the parent
309 function tem_auto_last(&$value, $key, $context) {
310 $rows =& $context['parent']['parent'];
311 if($rows['cur'] == count($rows['rows'])-1) # last row?
312 return true; # show once
315 # auto-show once, only when this is the last row of the parent
316 function tem_auto_first(&$value, $key, $context) {
317 $rows =& $context['parent']['parent'];
318 if($rows['cur'] == 0) # first row?
319 return true; # show once
322 # 'show' sections will be shown unless the corresponding data
324 function tem_auto_show(&$value) {
325 if($value === null) return true;
329 # 'empty' sections will be shown only if the corresponding data value is the
331 function tem_auto_empty(&$value) {
332 if($value === '') return true;
336 # 'nonempty' sections will not be shown if the corresponding data
337 # value is the empty string
338 function tem_auto_nonempty(&$value) {
339 if($value === '') return null;
343 # 'unset' sections will not be shown if the corresponding data
344 # value is not set (opposite of default)
345 function tem_auto_unset(&$value) {
346 if($value === null) {
353 # 'evenodd' sections are given an 'evenodd' attribute whose value
354 # alternates between 'even' and 'odd'.
355 function tem_auto_evenodd(&$values) {
357 if($values) foreach($values as &$value) {
358 $value['evenodd'] = $even ? 'even' : 'odd';
364 # 'once' sections are shown exactly once if the value is set (and not at all
365 # otherwise.) This is useful when an array value would otherwise cause the
366 # section to be displayed multiple times.
367 function tem_auto_once(&$value) {
368 if($value === null) return null;
372 function tem_auto_once_if(&$value) {
373 if($value) return true;
377 # 'once' sections are shown exactly once if php evaluates the value to false
378 # (and not at all otherwise.) This is useful when an array value would
379 # otherwise cause the section to be displayed multiple times.
380 function tem_auto_once_else(&$value) {
381 if($value) return null;
389 # Backward Compatibility
390 # ----------------------
392 function is_shown($piece) {
393 return $piece['args'][0] == 'hide';
396 function is_shown_sub_template($piece) {
397 return is_sub_template($piece) and is_shown($piece);
400 # Old-style templates don't show unless explicitly requested.
401 function tem_auto_hide(&$value, $key, $context) {
402 unset($context['data'][$key]);
406 # The old API is being used with the named sub-template,
407 # so hide it and insert a value slot for its expansion(s).
408 function &tem_is_old_sub($name, &$template) {
409 foreach($template['pieces'] as $key => &$piece) {
410 if(is_sub_template($piece)) {
411 if($piece['name'] == $name) {
412 if(!is_shown($piece)) {
413 # hide template unless explicitly show()n.
414 $piece['args'] = array('hide');
415 # insert a value slot with the same name (for the expansion).
416 $var = array('name' => $name, 'args' => array());
417 array_splice($template['pieces'], $key, 0, array($var));
421 $tem = tem_is_old_sub($name, $piece);
422 if($tem) return $tem;
433 $this->template = array('pieces' => array());
434 $this->data = array();
437 function set($key, $value = true) {
438 $this->data[$key] = $value;
441 function sets($hash) {
442 foreach($hash as $key => $value) {
443 $this->set($key, $value);
447 function append($key, $value) {
448 $this->data[$key] .= $value;
451 function prepend($key, $value) {
452 $this->data[$key] = $value . $this->data[$key];
455 function clear($key) {
456 unset($this->data[$key]);
460 return $this->data[$key];
463 function show($name) {
464 $tem = tem_is_old_sub($name, $this->template);
466 $this->data[$name] .= fill_template($tem, $this->data);
470 function show_separated($name) {
471 if($this->get($name)) {
472 $this->show($name . '_sep');
477 function load_str($str) {
478 $this->template =& parse_template($str);
481 function load($filename) {
482 $this->template =& parse_template_file($filename);
485 function run($tem = false) {
487 if(strlen($tem < 150 && file_exists($tem))) $this->load($tem);
488 else $this->load_str($tem);
491 return fill_template($this->template, $this->data);
494 function output($tem = false) {
495 print($this->run($tem));
498 # merge top-level sub-templates of $tem (object) into $this,
499 # supporting both new and old semantics.
500 function merge($tem) {
501 # append expansions to $this->data (old style)
503 $subs = $tem->top_subs('is_shown_sub_template');
504 if($subs) foreach($subs as $name => $val) {
505 $this->append($name, $val);
506 unset($tem->data[$name]); # so array_merge() won't overwrite things
509 # merge the data arrays and template trees (new style)
510 $this->data = array_merge($this->data, $tem->data);
511 merge_templates($this->template, $tem->template);
515 function merge_file($filename) {
516 $other_tem = new tem();
517 $other_tem->load($filename);
518 $this->merge($other_tem);
521 function top_sub_names($is_sub = 'is_sub_template') {
522 return array_keys(top_sub_templates($this->template, $is_sub));
525 function top_subs($is_sub = 'is_sub_template') {
527 $names = $this->top_sub_names($is_sub);
528 foreach($names as $name) {
529 $ret[$name] = $this->get($name);
534 # old name for show (deprecated)
535 function sub($name) {
540 function tem_init() {
541 if(!$GLOBALS['wfpl_template']) {
542 $GLOBALS['wfpl_template'] = new tem();
546 function tem_append($key, $value) {
548 $GLOBALS['wfpl_template']->append($key, $value);
551 function tem_prepend($key, $value) {
553 $GLOBALS['wfpl_template']->prepend($key, $value);
556 function tem_set($key, $value = true) {
558 $GLOBALS['wfpl_template']->set($key, $value);
561 function tem_sets($hash) {
563 $GLOBALS['wfpl_template']->sets($hash);
566 function tem_get($key) {
568 return $GLOBALS['wfpl_template']->get($key);
571 function tem_run($tem = false) {
573 return $GLOBALS['wfpl_template']->run($tem);
576 function tem_show($name) {
578 return $GLOBALS['wfpl_template']->show($name);
581 function tem_show_separated($name) {
583 $GLOBALS['wfpl_template']->show_separated($name);
586 function tem_load($filename) {
588 $GLOBALS['wfpl_template']->load($filename);
591 function tem_merge($tem) {
593 $GLOBALS['wfpl_template']->merge($tem);
596 function tem_merge_file($filename) {
598 $GLOBALS['wfpl_template']->merge_file($filename);
601 function tem_output($filename = false) {
603 $GLOBALS['wfpl_template']->output($filename);
606 function tem_top_subs() {
608 return $GLOBALS['wfpl_template']->top_subs();
611 function tem_top_sub_names() {
613 return $GLOBALS['wfpl_template']->top_sub_names();
616 function tem_load_new($filename) {
617 $old = $GLOBALS['wfpl_template'];
618 $GLOBALS['wfpl_template'] = new tem();
619 $GLOBALS['wfpl_template']->load($filename);
623 # deprecated (old name for show)
624 function tem_sub($name) {