ejnnr / chessboard Goto Github PK

function loadFen should throw an exception if the kings of one or both colors are missing in the FEN. Otherwise errors could occur in other functions.

To read a PGN file, we need a function which converts move like "Nf3" in array("g1", "f3").
In this example it has to check for every knight on the board if it can reach f3. It should throw an exception if the move isn't clear (if there are to knights, which could move on f3). And of course it also has to understand moves like "Ngf3" or "N1f3" and "0-0", "0-0-0". It should remove + (check) at the end of a move.

We also need a function, which splits the PGN up into single moves and loads the meta data.

In its first move a pawn is able to move two squares forward. This has to be implemented in the isPossibleMove function.

There should be a function, which creates a PGN from the $moves list.

In the current isPossibleMove function a pawn can take pieces, which are in front of him.

At the moment the doMove function does absolutely nothing.
We need it for version 1.0.

Version 1.0 should have a function, which returns the FEN from the current position saved in $board.

In PGN files there can be variations in parantheses. Of course they need to be parsed seomhow, but they also need to be stored in $moves.

En passant and castling aren't supported yet by the isValidMove function.
(The isValidMove function does not have to be changed, we only need to change the isPossibleMove function).

Why is there a semicolon after the closing bracket in line 3?

The doMove function should also add the move to the $moves array.

isPossibleMove should do the check if there's a piece of the same color on the target square for all pieces together. Then it could also do the check for pieces of different colors together.

For managing PGNs, the class needs a variable, in which the complete game (all moves) is saved.
This could be an array like this:

array(
   array("e2", "e4"),
   array("c7", "c5"),
   array("g1", "f3")
)

or like this:

array(
    "e4",
    "c5",
    "Nf3"
)

I think the first one is much better, because the moves like "Nf3" must be converted only once, when loading the PGN file and not every time they shall be used.