We Keep Coding

Pymongo MapReduce as sum of subarray element

I'm trying to perform MapReduce on this kind of data set:
{
"_id": "599861ce7ce78cd973746906",
"name": "Macias Rosario",
"col": [
{
"date": "15/03/2016",
"name": "MAGNEATO",
"amount": 313.86
},
{
"date": "08/08/2016",
"name": "FORTEAN",
"amount": 151.06
},
{
"date": "05/11/2014",
"name": "ECRATIC",
"amount": 291.68
}
]
}
Goal is to sum up all amount for name Macias Rosario. Currently I did with my code to group all by subelements this.col.name on this way:
mapper = Code("""
function() {
for (var index = 0; index < this.col.length; ++index) {
var col = this.col[index];
emit(col.name, col.amount );
}
}
""")
reducer = Code("""
function(key, values) {
var total = 0;
for( var i = 0; i < values.length; ++i){
total += values[i];
}
return value.price;
}
""")
result = collection.map_reduce(mapper, reducer, "myresult")
Has anyone have some idea how to reference, or group by this.name and not this.col.name because I don't know anymore and I'm driving nuts?
PS don't suggest me to use aggregate, did that way, want to try on this way also :)
Kind regards,

I hope the following code helps (works in pymongo as well)
This is my map function:
var mapFunction = function() {
for (var idx = 0; idx < this.col.length; idx++) {
var key = this.name;
var value = { amount : this.col[idx].amount };
emit(key, value);
}
};
And the following is my reduce function:
var reduceFunction = function(key, amountVl) {
reduceVal = { amount : 0 };
for (var idx = 0; idx < amountVl.length; idx++) {
reduceVal.amount += amountVl[idx].amount;
}
return reduceVal;
}
With your sample data it produces:
{ "_id" : "Macias Rosario", "value" : { "amount" : 756.6 } }

JSHint won't allow forEach in a for loop

I keep getting EsLint errors for having forEach in my loop. How can I fix the following code:
for (var i = 0; i < this.m_V.length; ++i) {
var o = this.m_V[i];
var node = o.m_Data.GetCurr(this.m_C);
if (node && node.m_datae.length) {
for (var j = 0; j < node.m_datae.length; ++j)
var dataelement = node.m_datae[j].m_dataat
AreaId.forEach(function(area) {
dataelement.forEach(function(value) {
if (area === value.m_V) {
if (vo.m_p) {
var a = v.m_p.map;
....
}
}
}
}, this);
}, this);
}
}
}
How can I move the forEach out of the code? I tried to move the forEach out but then it didn't know what my variables node and 'o' were.

Javascript- how do you convert this foreach loop to a regular for-loop?

This nested loop is running really slow in my app so I'm trying to change it to use regular for-loops instead of foreach. I'm a little confused on the find() part. Can someone help me convert this nested loop so that it doesn't use any foreach loops? thanks.
var filters = [];
if (selectionTagFilters.length > 0) {
for (var i = 0; i < selectionTagFilters.length; i++) {
filterTree.forEach(function find(tag) {
if (tag.tagCategoryId == selectionTagFilters[i].tag.tagCategoryId) {
tag.tags.forEach(function find(tag) {
if (tag.tagId == selectionTagFilters[i].tag.tagId) {
filters.push({ tagHeader: tag.tagHeader, tagId: tag.tagId, tagCategoryId: tag.tagCategoryId });
}
});
}
});
}
}

var filters = [],
selectionTagFilterItem = null,
filterTreeItem = null,
tagItem = null;
for(var i = 0, ii = selectionTagFilters.length; i < ii; i++) {
selectionTagFilterItem = selectionTagFilters[i];
for(var fti, ftii = filterTree.length; fti < ftii; fti++) {
filterTreeItem = filterTree[fti];
if (filterTreeItem.tagCategoryId != selectionTagFilterItem.tag.tagCategoryId) continue;
for(var ti = 0, tii = filterTreeItem.tags.length; ti < tii; ti++) {
tagItem = filterTreeItem.tags[ti];
if (tagItem.tagId != selectionTagFilterItem.tag.tagId) continue;
filters.push({ tagHeader: tagItem.tagHeader, tagId: tagItem.tagId, tagCategoryId: tagItem.tagCategoryId });
}
}
}

Repeat function in javascript

Could you please tell me how to make from this 4 functions just 1. Cause they all do one thing, with just one parameter changing all the time.
Also, I need to take the value of each time the function is running and put it into a new variable so I can after calculate it.
function getValue(age)
{
for (var i = 0; i < document.getElementsByName('age').length; i++)
{
if (document.getElementsByName('age')[i].checked)
{
return document.getElementsByName('age')[i].value;
}
}
}
function getBmiValue()
{
for (var i = 0; i < document.getElementsByName('bmi').length; i++)
{
if (document.getElementsByName('bmi')[i].checked)
{
return document.getElementsByName('bmi')[i].value;
}
}
}
function getFamValue()
{
for (var i = 0; i < document.getElementsByName('fam').length; i++)
{
if (document.getElementsByName('fam')[i].checked)
{
return document.getElementsByName('fam')[i].value;
}
}
}
function getDietValue()
{
for (var i = 0; i < document.getElementsByName('diet').length; i++)
{
if (document.getElementsByName('diet')[i].checked)
{
return document.getElementsByName('diet')[i].value;
}
}
}

function getValueByElementName(element_name)
{
for (var i = 0; i < document.getElementsByName(element_name).length; i++)
{
if (document.getElementsByName(element_name)[i].checked)
{
return document.getElementsByName(element_name)[i].value;
}
}
}
Or a little bit optimization:
function getValueByElementName(element_name)
{
var elements = document.getElementsByName(element_name);
for (var i = 0; i < elements.length; i++)
{
if (elements[i].checked)
return elements[i].value;
}
}

function getValue(tagname)
{
for (var i = 0; i < document.getElementsByName(tagname).length; i++)
{
if (document.getElementsByName(tagname)[i].checked)
{
return document.getElementsByName(tagname)[i].value;
}
}
}
Pass your element name as a variable in this function and call it.

Here is an example of what you can do:
function getValue(key) {
// get this once, not on each loop iteration
var elem = document.getElementsByName(key);
// cache the length too, so not to calculate it on each loop iteration
for (var i = 0, len = elem.length; i < len; i++) {
if (elem[i].checked) {
return elem[i].value;
// this will exit the function when it finds the FIRST one.
// Is that what you want?
}
}
}
// you can call above function like this:
getValue('age');
getValue('bmi');
getValue('fam');
getValue('diet');

Transform a JSON file?

I have a generated JSON file that I would like to transform. Is there an easy way to transform the "id"/"value" form of this JSON to a proper key/value JSON object, without using any frameworks?
These lines:
"value":"chrome",
"id":"foo"
would convert to:
"foo": "chrome"
Input JSON:
{"row":[
{
"column":[
{
"value":"chrome",
"id":"foo"
},
{
"value":0,
"id":"bar"
},
{
"value":"baz1",
"id":"baz"
},
{
"value":0,
"id":"legacy"
}
]
},
{
"column":[
{
"value":"firefox",
"id":"foo"
},
{
"value":0,
"id":"bar"
},
{
"value":"baz2",
"id":"baz"
},
{
"value":0,
"id":"legacy"
}
]
}
]
}
Desired JSON:
{"row":[
{
"foo":"chrome",
"bar":0,
"baz":"baz1",
"legacy":0
},
{
"foo":"firefox",
"bar":0,
"baz":"baz2",
"legacy":0
}
]
}

Here is the solution:
var result = {"row": []}
for (var i = 0; i < input["row"].length; i++) {
var object = {};
var column = input["row"][i]["column"];
for (var j = 0; j < column.length; j++) {
object[column[j]["id"]] = column[j]["value"];
}
result.row.push(object);
}
console.log(result);
input variable refers to your initial JSON object.
var input = {"row":[
{
"column":[
...

here is my function, i was typing it out allready before ioseb posted his answer so i figured it post it as well, it's linted and everything
function transform(data) {
"use strict";
var x, i, row, column, colNumb, out = {rows : []}, rownum = data.row.length;
for (x = 0; x < rownum; x += 1) {
row = {};
column = data.row[x].column;
colNumb = column.length;
for (i = 0; i < colNumb; i += 1) {
row[column[i].id] = column[i].value;
}
out.rows.push(row);
}
return out;
}