Shapefile index file: JavaScript parsing library

File extension

shx

KS implementation details

License: CC0-1.0

References

This page hosts a formal specification of Shapefile index file using Kaitai Struct. This specification can be automatically translated into a variety of programming languages to get a parsing library.

Usage

Runtime library

All parsing code for JavaScript generated by Kaitai Struct depends on the JavaScript runtime library. You have to install it before you can parse data.

The JavaScript runtime library is available at npm:

npm install kaitai-struct

Code

See the usage examples in the JavaScript notes.

Parse structure from an ArrayBuffer:

var arrayBuffer = ...;
var data = new ShapefileIndex(new KaitaiStream(arrayBuffer));

After that, one can get various attributes from the structure by accessing fields or properties like:

data.records // => the size of this section of the file in bytes must equal (header.file_length * 2) - 100

JavaScript source code to parse Shapefile index file

ShapefileIndex.js

// This is a generated file! Please edit source .ksy file and use kaitai-struct-compiler to rebuild

(function (root, factory) {
  if (typeof define === 'function' && define.amd) {
    define(['kaitai-struct/KaitaiStream'], factory);
  } else if (typeof module === 'object' && module.exports) {
    module.exports = factory(require('kaitai-struct/KaitaiStream'));
  } else {
    root.ShapefileIndex = factory(root.KaitaiStream);
  }
}(this, function (KaitaiStream) {
var ShapefileIndex = (function() {
  ShapefileIndex.ShapeType = Object.freeze({
    NULL_SHAPE: 0,
    POINT: 1,
    POLY_LINE: 3,
    POLYGON: 5,
    MULTI_POINT: 8,
    POINT_Z: 11,
    POLY_LINE_Z: 13,
    POLYGON_Z: 15,
    MULTI_POINT_Z: 18,
    POINT_M: 21,
    POLY_LINE_M: 23,
    POLYGON_M: 25,
    MULTI_POINT_M: 28,
    MULTI_PATCH: 31,

    0: "NULL_SHAPE",
    1: "POINT",
    3: "POLY_LINE",
    5: "POLYGON",
    8: "MULTI_POINT",
    11: "POINT_Z",
    13: "POLY_LINE_Z",
    15: "POLYGON_Z",
    18: "MULTI_POINT_Z",
    21: "POINT_M",
    23: "POLY_LINE_M",
    25: "POLYGON_M",
    28: "MULTI_POINT_M",
    31: "MULTI_PATCH",
  });

  function ShapefileIndex(_io, _parent, _root) {
    this._io = _io;
    this._parent = _parent;
    this._root = _root || this;

    this._read();
  }
  ShapefileIndex.prototype._read = function() {
    this.header = new FileHeader(this._io, this, this._root);
    this.records = [];
    var i = 0;
    while (!this._io.isEof()) {
      this.records.push(new Record(this._io, this, this._root));
      i++;
    }
  }

  var FileHeader = ShapefileIndex.FileHeader = (function() {
    function FileHeader(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    FileHeader.prototype._read = function() {
      this.fileCode = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.fileCode, [0, 0, 39, 10]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 39, 10], this.fileCode, this._io, "/types/file_header/seq/0");
      }
      this.unusedField1 = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.unusedField1, [0, 0, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 0, 0], this.unusedField1, this._io, "/types/file_header/seq/1");
      }
      this.unusedField2 = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.unusedField2, [0, 0, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 0, 0], this.unusedField2, this._io, "/types/file_header/seq/2");
      }
      this.unusedField3 = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.unusedField3, [0, 0, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 0, 0], this.unusedField3, this._io, "/types/file_header/seq/3");
      }
      this.unusedField4 = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.unusedField4, [0, 0, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 0, 0], this.unusedField4, this._io, "/types/file_header/seq/4");
      }
      this.unusedField5 = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.unusedField5, [0, 0, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([0, 0, 0, 0], this.unusedField5, this._io, "/types/file_header/seq/5");
      }
      this.fileLength = this._io.readS4be();
      this.version = this._io.readBytes(4);
      if (!((KaitaiStream.byteArrayCompare(this.version, [232, 3, 0, 0]) == 0))) {
        throw new KaitaiStream.ValidationNotEqualError([232, 3, 0, 0], this.version, this._io, "/types/file_header/seq/7");
      }
      this.shapeType = this._io.readS4le();
      this.boundingBox = new BoundingBoxXYZM(this._io, this, this._root);
    }

    /**
     * corresponds to s4be value of 9994
     */

    /**
     * corresponds to s4le value of 1000
     */

    return FileHeader;
  })();

  var Record = ShapefileIndex.Record = (function() {
    function Record(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    Record.prototype._read = function() {
      this.offset = this._io.readS4be();
      this.contentLength = this._io.readS4be();
    }

    return Record;
  })();

  var BoundingBoxXYZM = ShapefileIndex.BoundingBoxXYZM = (function() {
    function BoundingBoxXYZM(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    BoundingBoxXYZM.prototype._read = function() {
      this.x = new BoundsMinMax(this._io, this, this._root);
      this.y = new BoundsMinMax(this._io, this, this._root);
      this.z = new BoundsMinMax(this._io, this, this._root);
      this.m = new BoundsMinMax(this._io, this, this._root);
    }

    return BoundingBoxXYZM;
  })();

  var BoundsMinMax = ShapefileIndex.BoundsMinMax = (function() {
    function BoundsMinMax(_io, _parent, _root) {
      this._io = _io;
      this._parent = _parent;
      this._root = _root || this;

      this._read();
    }
    BoundsMinMax.prototype._read = function() {
      this.min = this._io.readF8be();
      this.max = this._io.readF8be();
    }

    return BoundsMinMax;
  })();

  /**
   * the size of this section of the file in bytes must equal (header.file_length * 2) - 100
   */

  return ShapefileIndex;
})();
return ShapefileIndex;
}));