265 

   266 def render_HTML_tree(tree, selected_node=None, render_node=None, caption=None):

   267     """

   268     Generate a pure HTML representation of a tree given as an instance

   269     of a logilab.common.tree.Node

   270 

   271     selected_node is the currently selected node (if any) which will

   272     have its surrounding <div> have id="selected" (which default

   273     to a bold border libe with the default CSS).

   274 

   275     render_node is a function that should take a Node content (Node.id)

   276     as parameter and should return a string (what will be displayed

   277     in the cell).

   278 

   279     Warning: proper rendering of the generated html code depends on html_tree.css

   280     """

   281     tree_depth = tree.depth_down()

   282     if render_node is None:

   283         render_node = str

   284 

   285     # helper function that build a matrix from the tree, like:

   286     # +------+-----------+-----------+

   287     # | root | child_1_1 | child_2_1 |

   288     # | root | child_1_1 | child_2_2 |

   289     # | root | child_1_2 |           |

   290     # | root | child_1_3 | child_2_3 |

   291     # | root | child_1_3 | child_2_4 |

   292     # +------+-----------+-----------+

   293     # from:

   294     # root -+- child_1_1 -+- child_2_1

   295     #       |             |

   296     #       |             +- child_2_2

   297     #       +- child_1_2

   298     #       |

   299     #       +- child1_3 -+- child_2_3

   300     #                    |

   301     #                    +- child_2_2

   302     def build_matrix(path, matrix):

   303         if path[-1].is_leaf():

   304             matrix.append(path[:])

   305         else:

   306             for child in path[-1].children:

   307                 build_matrix(path[:] + [child], matrix)

   308 

   309     matrix = []

   310     build_matrix([tree], matrix)

   311 

   312     # make all lines in the matrix have the same number of columns

   313     for line in matrix:

   314         line.extend([None]*(tree_depth-len(line)))

   315     for i in range(len(matrix)-1, 0, -1):

   316         prev_line, line = matrix[i-1:i+1]

   317         for j in range(len(line)):

   318             if line[j] == prev_line[j]:

   319                 line[j] = None

   320 

   321     # We build the matrix of link types (between 2 cells on a line of the matrix)

   322     # link types are :

   323     link_types = {(True,  True,  True ): 1, # T

   324                   (False, False, True ): 2, # |

   325                   (False, True,  True ): 3, # + (actually, vert. bar with horiz. bar on the right)

   326                   (False, True,  False): 4, # L

   327                   (True,  True,  False): 5, # -

   328                   }

   329     links = []

   330     for i, line in enumerate(matrix):

   331         links.append([])

   332         for j in range(tree_depth-1):

   333             cell_11 = line[j] is not None

   334             cell_12 = line[j+1] is not None

   335             cell_21 = line[j+1] is not None and line[j+1].next_sibling() is not None

   336             link_type = link_types.get((cell_11, cell_12, cell_21), 0)

   337             if link_type == 0 and i > 0 and links[i-1][j] in (1, 2, 3):

   338                 link_type = 2

   339             links[-1].append(link_type)

   340 

   341 

   342     # We can now generate the HTML code for the <table>

   343     s = u'<table class="tree">\n'

   344     if caption:

   345         s += '<caption>%s</caption>\n' % caption

   346 

   347     for i, link_line in enumerate(links):

   348         line = matrix[i]

   349 

   350         s += '<tr>'

   351         for j, link_cell in enumerate(link_line):

   352             cell = line[j]

   353             if cell:

   354                 if cell.id == selected_node:

   355                     s += '<td class="tree_cell" rowspan="2"><div id="selected" class="tree_cell">%s</div></td>' % (render_node(cell.id))

   356                 else:

   357                     s += '<td class="tree_cell" rowspan="2"><div class="tree_cell">%s</div></td>' % (render_node(cell.id))

   358             else:

   359                 s += '<td rowspan="2">&nbsp;</td>'

   360             s += '<td class="tree_cell_%d_1">&nbsp;</td>' % link_cell

   361             s += '<td class="tree_cell_%d_2">&nbsp;</td>' % link_cell

   362 

   363         cell = line[-1]

   364         if cell:

   365             if cell.id == selected_node:

   366                 s += '<td class="tree_cell" rowspan="2"><div id="selected" class="tree_cell">%s</div></td>' % (render_node(cell.id))

   367             else:

   368                 s += '<td class="tree_cell" rowspan="2"><div class="tree_cell">%s</div></td>' % (render_node(cell.id))

   369         else:

   370             s += '<td rowspan="2">&nbsp;</td>'

   371 

   372         s += '</tr>\n'

   373         if link_line:

   374             s += '<tr>'

   375             for j, link_cell in enumerate(link_line):

   376                 s += '<td class="tree_cell_%d_3">&nbsp;</td>' % link_cell

   377                 s += '<td class="tree_cell_%d_4">&nbsp;</td>' % link_cell

   378             s += '</tr>\n'

   379 

   380     s += '</table>'

   381     return s

   382