Flattening and unflattening objects to spreadsheets

In Flattening an object with dot syntax I showed how to take an object of more than 1 level deep and flatten it so it could be represented in a two-dimensional object like a spreadsheet. Now here’s the opposite, unflattening an object created that way. I also provide a library you can use for flattening and unflattening, as well as processing objects to and from spreadsheets

Here’s the library reference

MqxKdBrlw18FDd-X5zQLd7yz3TLx7pV4j

Consider this object,

{a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3})

1	{a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3})

which has been flattened from this original object

{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}

1	{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}

Note how an array is handled using the index number as a part of the flattened property

Here’s how to use.

flatten an object

var f = new cFlatten.Flattener();
 Logger.log( f.flatten({a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}));

1 2	var f = new cFlatten.Flattener(); Logger.log( f.flatten({a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}));

result

{g.2=3.0, b=2.0, g.1=2.0, c.d=3.0, g.0=1.0, a=1.0, c.e.f=25.0}

1	{g.2=3.0, b=2.0, g.1=2.0, c.d=3.0, g.0=1.0, a=1.0, c.e.f=25.0}

unflatten an object

var f = new cFlatten.Flattener();
 Logger.log( f.unFlatten(  {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}));

1 2	var f = new cFlatten.Flattener(); Logger.log( f.unFlatten( {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}));

result

{g=[1.0, 2.0, 3.0], b=2.0, c={d=3.0, e={f=25.0}}, a=1.0}

1	{g=[1.0, 2.0, 3.0], b=2.0, c={d=3.0, e={f=25.0}}, a=1.0}

create spreadsheet representation of values from an object

 var f = new cFlatten.Flattener();
  var obs = [{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2]}, {a:3,b:2,c:{d:2,e:{f:5}},g:[11,12,13]}];
  values = f.getValues ( obs);
  Logger.log(JSON.stringify(values));

var f = new cFlatten.Flattener();

var obs = [{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2]}, {a:3,b:2,c:{d:2,e:{f:5}},g:[11,12,13]}];

values = f.getValues ( obs);

Logger.log(JSON.stringify(values));

result

 [["a","b","c.d","c.e.f","g.0","g.1","g.2"],[1,2,3,25,1,2,""],[3,2,2,5,11,12,13]]

1	[["a","b","c.d","c.e.f","g.0","g.1","g.2"],[1,2,3,25,1,2,""],[3,2,2,5,11,12,13]]

create an unflattened object from spreadsheet values

var f = new cFlatten.Flattener();
 var v = [["a","b","c.d","c.e.f","g.0","g.1","g.2"],[1,2,3,25,1,2,""],[3,2,2,5,11,12,13]];
 Logger.log(JSON.stringify(f.getObjectsFromValues(v)));

var f = new cFlatten.Flattener();

var v = [["a","b","c.d","c.e.f","g.0","g.1","g.2"],[1,2,3,25,1,2,""],[3,2,2,5,11,12,13]];

Logger.log(JSON.stringify(f.getObjectsFromValues(v)));

result

 [{"a":1,"b":2,"c":{"d":3,"e":{"f":25}},"g":[1,2,""]},{"a":3,"b":2,"c":{"d":2,"e":{"f":5}},"g":[11,12,13]}]

1	[{"a":1,"b":2,"c":{"d":3,"e":{"f":25}},"g":[1,2,""]},{"a":3,"b":2,"c":{"d":2,"e":{"f":5}},"g":[11,12,13]}]

Putting it all together, start with an object, write it to a sheet

  var f = new cFlatten.Flattener();
  var obs = [{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2]}, {a:3,b:2,c:{d:2,e:{f:5}},g:[11,12,13]}];
  var ss = SpreadsheetApp.openById("12pTwh5Wzg0W4ZnGBiUI3yZY8QFoNI8NNx_oCPynjGYY");
  var sheet = ss.getSheetByName("flatten");
  var values = f.getValues(obs);
  sheet.getRange(1,1,values.length,values[0].length).setValues(values);

var f = new cFlatten.Flattener();

var obs = [{a:1,b:2,c:{d:3,e:{f:25}},g:[1,2]}, {a:3,b:2,c:{d:2,e:{f:5}},g:[11,12,13]}];

var ss = SpreadsheetApp.openById("12pTwh5Wzg0W4ZnGBiUI3yZY8QFoNI8NNx_oCPynjGYY");

var sheet = ss.getSheetByName("flatten");

var values = f.getValues(obs);

sheet.getRange(1,1,values.length,values[0].length).setValues(values);

result

a	b	c.d	c.e.f	g.0	g.1	g.2
1	2	3	25	1	2
3	2	2	5	11	12	13

Page Content hide

1 create an unflattened object from a sheet

2 The code

create an unflattened object from a sheet

var ss = SpreadsheetApp.openById("12pTwh5Wzg0W4ZnGBiUI3yZY8QFoNI8NNx_oCPynjGYY");
  var f = new cFlatten.Flattener();
  var sheet = ss.getSheetByName("flatten");
  var obs = f.getObjectsFromValues(sheet.getDataRange().getValues());
  Logger.log(JSON.stringify(obs));

var ss = SpreadsheetApp.openById("12pTwh5Wzg0W4ZnGBiUI3yZY8QFoNI8NNx_oCPynjGYY");

var f = new cFlatten.Flattener();

var sheet = ss.getSheetByName("flatten");

var obs = f.getObjectsFromValues(sheet.getDataRange().getValues());

Logger.log(JSON.stringify(obs));

result

  [{"a":1,"b":2,"c":{"d":3,"e":{"f":25}},"g":[1,2,""]},{"a":3,"b":2,"c":{"d":2,"e":{"f":5}},"g":[11,12,13]}]

1	[{"a":1,"b":2,"c":{"d":3,"e":{"f":25}},"g":[1,2,""]},{"a":3,"b":2,"c":{"d":2,"e":{"f":5}},"g":[11,12,13]}]

The code

Here’s the library reference

MqxKdBrlw18FDd-X5zQLd7yz3TLx7pV4j

/**
 * @param {string} optObKeep if specified,objects of this key wont be flattened
 * @return {Flattener} self
 */
function getLibraryInfo () {

  return { 
    info: {
      name:'cFlatten',
      version:'2.2.1',
      key:'MqxKdBrlw18FDd-X5zQLd7yz3TLx7pV4j',
    },
    dependencies:[
    ]
  }; 
} 
var Flattener = function(optObKeep) {
  var self = this;
  self.obKeep = optObKeep || null;
  self.keepDates = false;
  self.setKeepDates = function (keep) {
    self.keepDates = keep;
    return self;
  };
  
  return self;          
};

  
/** get an array of objects from sheetvalues and unflatten them
 * @parameter {Array.object} values a 2 dim array of values return by spreadsheet.getValues()
 * @return {object} an unflatten object
 **/
Flattener.prototype.getObjectsFromValues = function (values) {
  var self = this;
  var obs = [];
  for (var i=1 ; i < values.length ; i++){
    var k = 0;
    obs.push(self.unFlatten(values[i].reduce (function (p,c) {
      p[values[0][k++]] = c;
      return p;
    } , {})));
  }
  return obs;
  
};

/** get values from an array of objects by flattening and sorting all the keys found
 * @parameter {Array.object} obs an array of objects
 * @return {Array.object} a two dim array of values
 **/ 
Flattener.prototype.getValues = function(obs) {
  var self = this;
  var headings = self.getHeadingMap(obs);
  var headingValues = Object.keys(headings);
  var width = headingValues.length;
  
  return [headingValues].concat(obs.map ( function (row) {
    var v =[];
    for (var i=0;i<width;i++)v.push('');
    var o = self.flatten(row);
    Object.keys(o).forEach( function (k) {
      v[headings[k]] = o[k];
    });
    return v;
  }));
  
};
  
/** get headings from an array of objects by flattening and sorting all the keys found
 * @parameter {Array.object} obs an array of objects
 * @return {object} a flattened object with a property for each key and its position
 **/ 
Flattener.prototype.getHeadingMap = function(obs) {
  var self = this;
  var headings = {},n=0;
  obs.forEach ( function (row) {
    headings = Object.keys(self.flatten(row)).reduce(function(p,c) {
      if (!p.hasOwnProperty(c)) {
        p[c] = 0;
      }
      return p;
    },headings );
  });
  // sort the keys
  return Object.keys(headings).sort ( function (a,b) {
    return a > b ? 1 : ( a===b ? 0 : -1);
  })
  .reduce(function (p,c) {
    p[c] = n++;
    return p;
  },{});
};
  
/** unFlatten an ob
 * creates this {a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}
 * from this {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}
 * @parameter {object} ob the object to be unflattened
 * @return {object} the unflattened object
 **/
Flattener.prototype.unFlatten = function (ob) {
  var self = this;
  return Object.keys(ob).reduce(function (p,c) {
    var pk=p, keys = c.split(".");
    for (var i=0; i < keys.length-1 ;i++) {
      if (!pk.hasOwnProperty(keys[i])) { 
        pk[keys[i]] = self.isNumber(keys[i+1]) ? [] : {};
      }
      pk = pk[keys[i]];
    }
    var k = keys[keys.length-1];
    pk[k] = ob[c];
    return p;
  },Array.isArray(ob) ? [] : {});
  
};

/** flatten an ob
 * turns this {a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}
 * into this {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}
 * @parameter {object} ob the object to be flattened
 * @return {object} the flattened object
 **/
Flattener.prototype.flatten = function(ob) {
  var self = this;
  return  self.objectDot (ob).reduce(function(p,c){
    p[c.key] = c.value;
    return p;
  },{});
};

Flattener.prototype.objectSplitKeys  = function (ob,obArray,keyArray) {
  obArray = obArray || [];
  var self = this;
  //turns this {a:1,b:2,c:{d:3,e:{f:25}}}
  // into this, so that the keys can be joined to make dot syntax
  //[{key:[a], value:1},{key:[b], value:2} , {key:[c,d], value:3}, {key:[c,e,f], value:25}]
  
  if (self.isObject(ob)) {

    Object.keys(ob).forEach ( function (k) {
      var ka = keyArray ? keyArray.slice(0) : [];
      ka.push(k);

      if(self.isObject(ob[k])  && (!self.obKeep || !ob[k][self.obKeep]) && ( !self.keepDates || !self.isDateObject(ob[k]))) {
        self.objectSplitKeys (ob[k],obArray,ka);
      }
      else {
        obArray.push ( {key:ka, value:ob[k]} );
      }
      
    });
  }
  else {
    obArray.push(ob);
  }
  
  return obArray;
};

  
Flattener.prototype.objectDot = function (ob) {
  var self = this;
  return self.objectSplitKeys (ob).map ( function (o) {
    return {key:o.key.join("."), value:o.value};
  });
};

Flattener.prototype.isObject  = function (obj) {
  return obj === Object(obj);
}; 

Flattener.prototype.isNumber = function (s) {
  return !isNaN(parseInt(s,10)) ;
};

Flattener.prototype.isDateObject = function (ob) {
  return this.isObject(ob) && ob.constructor && ob.constructor.name === "Date";
};

/** get headings from an array of objects by flattening and sorting all the keys found
 * @parameter {Array.object} obs an array of objects
 * @return {Array.object} an array of heading values
 **/ 
Flattener.prototype.getHeadings = function(obs) {
  return Object.keys(self.getHeadingMap(obs));
};

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/**

* @param {string} optObKeep if specified,objects of this key wont be flattened

* @return {Flattener} self

function getLibraryInfo () {

return {

info: {

name:'cFlatten',

version:'2.2.1',

key:'MqxKdBrlw18FDd-X5zQLd7yz3TLx7pV4j',

dependencies:[

]

};

}

var Flattener = function(optObKeep) {

var self = this;

self.obKeep = optObKeep || null;

self.keepDates = false;

self.setKeepDates = function (keep) {

self.keepDates = keep;

return self;

};

return self;

};

/** get an array of objects from sheetvalues and unflatten them

* @parameter {Array.object} values a 2 dim array of values return by spreadsheet.getValues()

* @return {object} an unflatten object

**/

Flattener.prototype.getObjectsFromValues = function (values) {

var self = this;

var obs = [];

for (var i=1 ; i < values.length ; i++){

var k = 0;

obs.push(self.unFlatten(values[i].reduce (function (p,c) {

p[values[0][k++]] = c;

return p;

} , {})));

}

return obs;

};

/** get values from an array of objects by flattening and sorting all the keys found

* @parameter {Array.object} obs an array of objects

* @return {Array.object} a two dim array of values

**/

Flattener.prototype.getValues = function(obs) {

var self = this;

var headings = self.getHeadingMap(obs);

var headingValues = Object.keys(headings);

var width = headingValues.length;

return [headingValues].concat(obs.map ( function (row) {

var v =[];

for (var i=0;i<width;i++)v.push('');

var o = self.flatten(row);

Object.keys(o).forEach( function (k) {

v[headings[k]] = o[k];

});

return v;

}));

};

/** get headings from an array of objects by flattening and sorting all the keys found

* @parameter {Array.object} obs an array of objects

* @return {object} a flattened object with a property for each key and its position

**/

Flattener.prototype.getHeadingMap = function(obs) {

var self = this;

var headings = {},n=0;

obs.forEach ( function (row) {

headings = Object.keys(self.flatten(row)).reduce(function(p,c) {

if (!p.hasOwnProperty(c)) {

p[c] = 0;

}

return p;

},headings );

});

// sort the keys

return Object.keys(headings).sort ( function (a,b) {

return a > b ? 1 : ( a===b ? 0 : -1);

})

.reduce(function (p,c) {

p[c] = n++;

return p;

},{});

};

/** unFlatten an ob

* creates this {a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}

* from this {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}

* @parameter {object} ob the object to be unflattened

* @return {object} the unflattened object

**/

Flattener.prototype.unFlatten = function (ob) {

var self = this;

return Object.keys(ob).reduce(function (p,c) {

var pk=p, keys = c.split(".");

for (var i=0; i < keys.length-1 ;i++) {

if (!pk.hasOwnProperty(keys[i])) {

pk[keys[i]] = self.isNumber(keys[i+1]) ? [] : {};

}

pk = pk[keys[i]];

}

var k = keys[keys.length-1];

pk[k] = ob[c];

return p;

},Array.isArray(ob) ? [] : {});

};

/** flatten an ob

* turns this {a:1,b:2,c:{d:3,e:{f:25}},g:[1,2,3]}

* into this {a:1,b:2,"c.d":3,"c.e.f":25,"g.0":1,"g.1":2,"g.2":3}

* @parameter {object} ob the object to be flattened

* @return {object} the flattened object

**/

Flattener.prototype.flatten = function(ob) {

var self = this;

return self.objectDot (ob).reduce(function(p,c){

p[c.key] = c.value;

return p;

},{});

};

Flattener.prototype.objectSplitKeys = function (ob,obArray,keyArray) {

obArray = obArray || [];

var self = this;

//turns this {a:1,b:2,c:{d:3,e:{f:25}}}

// into this, so that the keys can be joined to make dot syntax

//[{key:[a], value:1},{key:[b], value:2} , {key:[c,d], value:3}, {key:[c,e,f], value:25}]

if (self.isObject(ob)) {

Object.keys(ob).forEach ( function (k) {

var ka = keyArray ? keyArray.slice(0) : [];

ka.push(k);

if(self.isObject(ob[k]) && (!self.obKeep || !ob[k][self.obKeep]) && ( !self.keepDates || !self.isDateObject(ob[k]))) {

self.objectSplitKeys (ob[k],obArray,ka);

}

else {

obArray.push ( {key:ka, value:ob[k]} );

}

});

}

else {

obArray.push(ob);

}

return obArray;

};

Flattener.prototype.objectDot = function (ob) {

var self = this;

return self.objectSplitKeys (ob).map ( function (o) {

return {key:o.key.join("."), value:o.value};

});

};

Flattener.prototype.isObject = function (obj) {

return obj === Object(obj);

};

Flattener.prototype.isNumber = function (s) {

return !isNaN(parseInt(s,10)) ;

};

Flattener.prototype.isDateObject = function (ob) {

return this.isObject(ob) && ob.constructor && ob.constructor.name === "Date";

};

/** get headings from an array of objects by flattening and sorting all the keys found

* @parameter {Array.object} obs an array of objects

* @return {Array.object} an array of heading values

**/

Flattener.prototype.getHeadings = function(obs) {

return Object.keys(self.getHeadingMap(obs));

};

For more snippets topics, see:

Desktop Liberation

The definitive resource for Google Apps Script and Microsoft Office automation

Flattening and unflattening objects to spreadsheets

create an unflattened object from a sheet

The code