lib.php

<?php

/* FPU EDIT (bkt) 1/2010
* These functions are used for course sorting and for course grouping.
* Used in the function below (print_my_courses()).
*/

/**
 * This function is used to sort an array of course objects
 * by chronological order based on the FPU naming scheme.
 */
function fpu_course_sort_compare($course_a, $course_b)
{
    // We want to sort by our FPU course naming standard.
    // Courses that are EARLIER in time are less than courses that are LATER in time.
    // Thus 09 < 10, SP < FA
    // Five parts: year, term, subject, course, and section.
    // YEAR: Consecutive order. 08, 09, 10, 11, 12, etc.
    // TERM: First letter, then SP < SS < FA
    // COURSE: Alphabetical
    // COURSE: Numeric/Alphabetical
    // SECTION: Albpabetical

    // If the two courses are identical, they are of course... well, identical.
    // That means we have other issues, but that is not this function's concern.
    if($course_a->shortname == $course_b->shortname)
        return 0;

    // If one is blank... well, it shouldn't be, but make it first.
    if(empty($course_a->shortname) && !empty($course_b->shortname)) {
      return -1;
    } elseif(!empty($course_a->shortname) && empty($course_b->shortname)) {
      return 1;
    }

    // Get the various parts of a standard or almost standard course name.
    $parts_a = fpu_course_parts($course_a->shortname);
    $parts_b = fpu_course_parts($course_b->shortname);
    
    // If a course doesn't look like a standard course,
    // and the other course does, the non-standard one comes first.
    // If they're both non-standard, just do a string compare.
    if($parts_a == false && $parts_b != false) {
      return -1;
    } elseif($parts_b == false && $parts_a != false) {
      return 1;
    } elseif($parts_a == false && $parts_b == false) {
      if(strtolower($course_a->shortname) > strtolower($course_b->shortname))
        return 1;
      elseif(strtolower($course_a->shortname) < strtolower($course_b->shortname))
        return -1;
      else
        return 0;
    }

    // Years that start with letters come before years that are numbers.
    $year_a = $parts_a[1];
    $year_b = $parts_b[1];
    if(is_numeric($year_a) && !is_numeric($year_b)) {
      return 1;
    } elseif(!is_numeric($year_a) && is_numeric($year_b)) {
      return -1;
    }

    // Lower years come before higher years.
    $i_year_a = (int) $year_a;
    $i_year_b = (int) $year_b;
    if($i_year_a < $i_year_b) {
      return 1;
    } elseif($i_year_b < $i_year_a) {
      return -1;
    }

    // The last two letters of the term part indicate the term.
    // TODO: IMPLEMENT FIRST LETTER DEALIO
    $term_a = substr($parts_a[2], -2);
    $term_b = substr($parts_b[2], -2);
    $compare = fpu_term_compare($term_a, $term_b);
    if($compare != 0) {
      return $compare * -1; // * -1 cause we're sorting in reverse here
    }

    // Within the year and term, hidden courses come last.
    if($course_a->visible == 0 && $course_b->visible == 1) {
      return 1;
    } elseif($course_a->visible == 1 && $course_b->visible == 0) {
      return -1;
    }

    // Coures part
    $course_a = $parts_a[3];
    $course_b = $parts_b[3];
    if($course_a < $course_b) {
      return -1;
    } elseif($course_a > $course_b) {
      return 1;
    }

    // And finally section
    $sect_a = $parts_a[4];
    $sect_b = $parts_b[4];
    if($sect_a < $sect_b) {
      return -1;
    } elseif($sect_a > $sect_b) {
      return 1;
    }

    // End of the line. Do a string compare.
    if(strtolower($course_a->shortname) > strtolower($course_b->shortname))
      return 1;
    elseif(strtolower($course_a->shortname) < strtolower($course_b->shortname))
      return -1;
    else
      return 0;
}

/**
 * Compare one term (SS, FA, SP) to another.
 */
function fpu_term_compare($term1, $term2) {
  if($term1 == "SP") {
    if($term2 == "SS" || $term2 == "FA") {
      return -1;
    } else {
      return 0;
    }
  } elseif($term1 == "SS") {
    if($term2 == "SP") {
      return 1;
    } elseif($term2 == "SS") {
      return 0;
    } else {
      return -1;
    }
  } elseif($term1 == "FA") {
    if($term2 == "SP" || $term2 == "SS") {
      return 1;
    } else {
      return 0;
    }
  }

  return 0; // shouldn't happen :(
}

/**
 * Returns the parts of the course name, if found.
 * If not, returns false.
 *
 * Array
 * (
 *     [0] => 10/GFA-PACS-710/PS-372-ALL
 *     [1] => 10
 *     [2] => GFA
 *     [3] => PACS-710/PS-372
 *     [4] => ALL
 * )
 */
function fpu_course_parts($course) {
  $regex = "/^([A-Z0-9]{2,3})\/([A-Z0-9]+)-(.*)-(.*)$/i";
  $matches = array();
  $matched = preg_match($regex, $course, $matches);

  if($matched == false || $matched == 0) {
    return false;
  } else {
    return $matches;
  }
}

/* END FPU EDIT */