Annotation of doc/homework/newtag.html, revision 1.1
1.1 ! albertel 1: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
! 2: <html>
! 3: <head>
! 4: <title>Making a New Tag Handler</title>
! 5: </head>
! 6:
! 7: <body>
! 8: <h1>Making a New Tag Handler</h1>
! 9:
! 10: <h2>Required Actions</h2>
! 11: <ul>
! 12: <li>
! 13: you will need to call <i>&Apache::lonxml::register()</i>
! 14: to register the tag name and the namespace it is in, most of
! 15: the time this is in the BEGIN block of the handler
! 16: </li>
! 17: <li>
! 18: you will need to create both <i>&start_newtag()</i> and
! 19: <i>&end_newtag()</i> functions.
! 20: </li>
! 21: <li>
! 22: these function will need to do one of:
! 23: <ol>
! 24: <li>
! 25: return a non-null string
! 26: </li>
! 27: <li>
! 28: return a null string (and expect that for some targets a
! 29: default output may be generated for it)
! 30: </li>
! 31: <li>
! 32: return a list containing a null string for the first
! 33: element and the string 'no' for the second element., this
! 34: will make sure that the result is a null string and any
! 35: default action normally taken will be skipped
! 36: </li>
! 37: </ol>
! 38: <li>
! 39: These functions will have six arguments passed to them
! 40: <ol>
! 41: <li>
! 42: <i>$target</i> a scalar cotaing the string of the target
! 43: that is being parsed for. The current possibilities
! 44: include web, tex, grade, answer, modified, edit, meta,
! 45: analyze. Although more may be added in the future, you
! 46: must guarentee that you return a blank string for any
! 47: target you don't specifically handle.
! 48: </li>
! 49: <li>
! 50: <i>$token</i> a HTML::LCParser token object,You probably
! 51: want to avoid using the parameter information inside of
! 52: this, you most likely want to use <i>$paramstack</i> and
! 53: <i>&Apache::lonxml::get_param()</i>
! 54: </li>
! 55: <li>
! 56: <i>$tagstack</i> a stack pointer of the names of the tags
! 57: that are currently open, don't modify
! 58: </li>
! 59: <li>
! 60: <i>$paramstack</i> a stack pointer of the parameters
! 61: passed to the currently open tags, don't modify, and you
! 62: probably should use this only as a parameter to
! 63: <i>&Apache::lonxml::get_param</i>
! 64: </li>
! 65: <li>
! 66: <i>$parser</i> a stack pointer of the current stack of
! 67: HTML::LCParser objects. You probably only want to use the
! 68: top one. Also your functions may manipulate this object
! 69: and grab more tokens from it but be carefule about
! 70: unbalancing it, also avoid calling the ->get_text()
! 71: routine unless you really not what you are doing
! 72: (<i>&Apache::lonxml::get_all_text()</i> is probably
! 73: what you want to use.
! 74: </li>
! 75: <li>
! 76: <i>$safeeval</i> a pointer to the safe space interpreter,
! 77: You probably don't what to do anything with this directly,
! 78: <i>&Apache::run::run</i> and other functions need this
! 79: argument and will use it correctly.
! 80: </li>
! 81: <li>
! 82: <i>$style</i> a Hash reference, it contains mappings
! 83: between tags and style file definitions. Few functions
! 84: will need to use this.
! 85: </li>
! 86: </ol>
! 87: </li>
! 88: <li>
! 89: if it is a new response tag it needs to
! 90: <ul>
! 91: <li>
! 92: call <i>&Apache::response::start_response()</i> in the
! 93: start_newtag function and
! 94: <i>&Apache::response::end_response()</i> at the end of
! 95: the end_newtag function
! 96: </li>
! 97: <li>
! 98: set the required data for a responseid from the
! 99: datastorage document
! 100: </li>
! 101: <li>
! 102: use the functions
! 103: <i>&Apache::response::check_for_previous()</i> and
! 104: <i>&Apache::response::handle_previous()</i> to check
! 105: if a student's reponse has been submitted before.
! 106: </li>
! 107: <li>
! 108: call <i>&Apache::response::setup_params()</i> if it is
! 109: expecting external parameters to be set for it.
! 110: </li>
! 111: </ul>
! 112: </li>
! 113: </ul>
! 114: <h2>Things to not do</h2>
! 115: <ul>
! 116: <li>
! 117: there is no direct access to the Apache Request object. It is
! 118: <b>very</b> unlikely that you need it, any data you want is
! 119: either in %ENV, a global variable listed below or in the xml
! 120: documentation, or should be gotten through an Apache::lonnet
! 121: function
! 122: </li>
! 123: <li>
! 124: print, either return it in the result, or use the
! 125: debug/warning/error facility of Apache::lonxml
! 126: </li>
! 127: <li>
! 128: use the <i>get_text()</i> procedure of the $parser
! 129: HTML::LCParser object
! 130: </li>
! 131: <li>
! 132: access the paramater attributes of the $token HTML::LCParser
! 133: object
! 134: </li>
! 135: </ul>
! 136: <h2>Interesting Globals</h2>
! 137: <ul>
! 138: <li> lonhomework globals
! 139: <ul>
! 140: <li>
! 141: <i>%Apache::lonhomework::history</i> the data from a restore
! 142: call for the current symb
! 143: </li>
! 144: <li>
! 145: <i>%Apache::lonhomework::results</i> the hash that will be
! 146: cstored at the end of the current execution
! 147: </li>
! 148: <li>
! 149: <i>$Apache::lonhomework::browse</i> the result of an allowed
! 150: request for the bre priviledge on the current file
! 151: </li>
! 152: <li>
! 153: <i>$Apache::lonhomework::viewgrades</i> the result of an
! 154: allowed request on the vgr priviledge for the current course
! 155: </li>
! 156: <li>
! 157: <i>$Apache::lonhomework::type</i> the current type of the
! 158: resource, either '', exam, homework, quiz, form, or survey
! 159: </li>
! 160: <li>
! 161: <i>%Apache::lonhomework::analyze</i> in analyze mode all data
! 162: to be returned is sotred in here.
! 163: </li>
! 164: </ul>
! 165: </li>
! 166: <li>
! 167: inputtag globals
! 168: <ul>
! 169: <li>
! 170: <i>@Apache::inputtags::input</i> list of current input ids
! 171: </li>
! 172: <li>
! 173: <i>@Apache::inputtags::inputlist</i> list of all input ids
! 174: seen in this problem
! 175: </li>
! 176: <li>
! 177: <i>@Apache::inputtags::response</i> list of all current
! 178: response ids
! 179: </li>
! 180: <li>
! 181: <i>@Apache::inputtags::responselist</i> list of all
! 182: response ids seen in this problem
! 183: </li>
! 184: <li>
! 185: <i>@Apache::inputtags::previous</i> list of whether or not
! 186: a specific response was previously used
! 187: </li>
! 188: <li>
! 189: <i>$Apache::inputtags::part</i> id of current part, 0
! 190: means that no part is current (inside <problem>
! 191: only)
! 192: </li>
! 193: <li>
! 194: <i>@Apache::inputtags::status</i> list of problem date
! 195: statuses, the first element is for <problem> if
! 196: there is a second element it is for the current
! 197: <part> possible values are CLOSED, CAN_ANSWER,
! 198: SHOW_ANSWER, UNCHECKEDOUT
! 199: </li>
! 200: <li>
! 201: <i>%Apache::inputtags::params</i> hash of defined params
! 202: for the current response
! 203: </li>
! 204: <li>
! 205: <i>@Apache::inputtags::import</i> list of all ids, from
! 206: <import>s, these get join()ed and prepended to the
! 207: ids in the @Apache::inputtags::response and
! 208: @Apache::inputtags::responselist variables
! 209: </li>
! 210: </ul>
! 211: </li>
! 212: </ul>
! 213: <h2>Interesting Function</h2>
! 214:
! 215:
! 216: <hr>
! 217: <address><a href="mailto:albertel@msu.edu"></a></address>
! 218: <!-- Created: Thu Jun 6 03:47:04 EDT 2002 -->
! 219: <!-- hhmts start -->
! 220: Last modified: Thu Jun 6 04:46:00 EDT 2002
! 221: <!-- hhmts end -->
! 222: </body>
! 223: </html>
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