I've done some searching around the web and nothing seems to solve my problem. I have the following jQuery code:
function youtube_data_parser(data) {
//---> parse video data - start
var qsToJson = function(qs) {
var res = {};
var pars = qs.split('&');
var kv, k, v;
for (i in pars) {
kv = pars[i].split('=');
k = kv[0];
v = kv[1];
res[k] = decodeURIComponent(v);
}
return res;
}
//---> parse video data - end
var get_video_info = qsToJson(data);
if (get_video_info.status == 'fail') {
return {
status: "error",
code: "invalid_url",
msg: "check your url or video id"
};
} else {
// remapping urls into an array of objects
//--->parse > url_encoded_fmt_stream_map > start
//will get the video urls
var tmp = get_video_info["url_encoded_fmt_stream_map"];
if (tmp) {
tmp = tmp.split(',');
for (i in tmp) {
tmp[i] = qsToJson(tmp[i]);
}
get_video_info["url_encoded_fmt_stream_map"] = tmp;
}
//--->parse > url_encoded_fmt_stream_map > end
//--->parse > player_response > start
var tmp1 = get_video_info["player_response"];
if (tmp1) {
get_video_info["player_response"] = JSON.parse(tmp1);
}
//--->parse > player_response > end
//--->parse > keywords > start
var keywords = get_video_info["keywords"];
if (keywords) {
key_words = keywords.replace(/\+/g, ' ').split(',');
for (i in key_words) {
keywords[i] = qsToJson(key_words[i]);
}
get_video_info["keywords"] = {
all: keywords.replace(/\+/g, ' '),
arr: key_words
};
}
//--->parse > keywords > end
//return data
return {
status: 'success',
raw_data: qsToJson(data),
video_info: get_video_info
};
}
}
function getVideoInfo() {
var get_video_url = $('#ytdlUrl').val();
var get_video_id = getUrlVars(get_video_url)['v'];
var video_arr_final = [];
var ajax_url = "video_info.php?id=" + get_video_id;
$.get(ajax_url, function(d1) {
var data = youtube_data_parser(d1);
var video_data = data.video_info;
var player_info = data.video_info.player_response;
var video_title = player_info.videoDetails.title.replace(/\+/g, ' ');
var fmt_list = video_data.fmt_list.split(',');
var video_thumbnail_url = video_data.thumbnail_url;
var video_arr = video_data.url_encoded_fmt_stream_map;
//create video file array
$.each(video_arr, function(i1, v1) {
var valueToPush = {};
valueToPush.video_url = v1.url;
valueToPush.video_thumbnail_url = video_thumbnail_url;
valueToPush.video_title = video_title;
$.each(fmt_list, function(i2, v2) {
var fmt = v2.split('/');
var fmt_id = fmt[0];
var fmt_quality = fmt[1];
if (fmt_id == v1.itag) {
valueToPush.fmt_id = fmt_id;
valueToPush.fmt_quality = fmt_quality;
}
});
video_arr_final.push(valueToPush);
});
});
return video_arr_final;
}
function getUrlVars(url) {
var vars = {};
var parts = url.replace(/[?&]+([^=&]+)=([^&]*)/gi, function(m, key, value) {
vars[key] = value;
});
return vars;
}
function fillInOptions(ytOptions) {
//console.log(ytOptions);
//alert(ytOptions[0]);
var ytFill = ytOptions;
console.log(ytFill);
//ytFill.forEach(function(i,v) {
var ytdlOptions = $('#ytdlOptions');
ytFill.forEach(function(i,v) {
console.log(i);
ytdlOptions.append(new Option(v.fmt_quality, v.fmt_id));
});
return true;
}
function showYTDLLoader() {
$('#ytdlInput').fadeOut(1000, function() {
$('#ytdlLoader').fadeIn(500);
});
var options = getVideoInfo();
//console.log(options);
if (fillInOptions(options) == true) {
//do rest
}
}
function showYTDLOptions() {
return true;
}
function startDownload() {
showYTDLLoader();
}
function hideYTDLLoader() {
$('#ytdlLoader').fadeOut(500);
}
function animateCSS(element, animationName, callback) {
const node = $(element);
node.addClass(animationName);
function handleAnimationEnd() {
node.removeClass(animationName);
node.animationend = null;
if (typeof callback === 'function') callback();
}
node.animationend = handleAnimationEnd();
}
When my button is clicked, I call showYTDLLoader() which gets an array of objects from the YouTube API that looks like this:
[
{
"video_url": "https://r7---sn-uxanug5-cox6.googlevideo.com/videoplayback?expire=1572496003&ei=Iw66Xa24H8PL3LUPiN25mAs&ip=2001%3A8003%3A749b%3Aa01%3A5cd8%3Ac610%3A6402%3Ad0fe&id=o-ADsVnoOoBQ6-SWzYZU7gHES06s7xQptJG6hn9WcakITY&itag=22&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-uxanug5-cox6%2Csn-ntqe6n7r&ms=au%2Crdu&mv=m&mvi=6&pl=39&initcwndbps=1655000&mime=video%2Fmp4&ratebypass=yes&dur=917.768&lmt=1572418007364260&mt=1572474311&fvip=4&fexp=23842630&c=WEB&txp=5535432&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cratebypass%2Cdur%2Clmt&sig=ALgxI2wwRgIhAIp-4gyUTLoXFetbY0ha_YnR7DJqsp_MNjjIxqDdfPZJAiEA_WPd21jgX9broBcigf8rcSEVoJb2_NX7t3XZQqytsSM%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgacvP3zjEq-rVEZFrX7a_hC6TR-Zab7Ii-Fbaupjs_PcCIHdZht4l4ioYL3ERz7WNiSbnOnhm5iYxEECaQXPP2hUp",
"video_title": "Arnold Schwarzenegger on Son-in-law Chris Pratt, Pranking Sylvester Stallone & Terminator’s Return",
"fmt_id": "22",
"fmt_quality": "1280x720"
},
{
"video_url": "https://r7---sn-uxanug5-cox6.googlevideo.com/videoplayback?expire=1572496003&ei=Iw66Xa24H8PL3LUPiN25mAs&ip=2001%3A8003%3A749b%3Aa01%3A5cd8%3Ac610%3A6402%3Ad0fe&id=o-ADsVnoOoBQ6-SWzYZU7gHES06s7xQptJG6hn9WcakITY&itag=18&source=youtube&requiressl=yes&mm=31%2C29&mn=sn-uxanug5-cox6%2Csn-ntqe6n7r&ms=au%2Crdu&mv=m&mvi=6&pl=39&initcwndbps=1655000&mime=video%2Fmp4&gir=yes&clen=44248820&ratebypass=yes&dur=917.768&lmt=1572416976690256&mt=1572474311&fvip=4&fexp=23842630&c=WEB&txp=5531432&sparams=expire%2Cei%2Cip%2Cid%2Citag%2Csource%2Crequiressl%2Cmime%2Cgir%2Cclen%2Cratebypass%2Cdur%2Clmt&sig=ALgxI2wwRQIhANTZJlBHFWQWCnfK11yvLiPUV26c6NzvqIMKjDwmsByMAiBUSy0ZJMo4GdHSiRU4xBDDLxLtzwKZAqAKCiB-1aViDQ%3D%3D&lsparams=mm%2Cmn%2Cms%2Cmv%2Cmvi%2Cpl%2Cinitcwndbps&lsig=AHylml4wRAIgacvP3zjEq-rVEZFrX7a_hC6TR-Zab7Ii-Fbaupjs_PcCIHdZht4l4ioYL3ERz7WNiSbnOnhm5iYxEECaQXPP2hUp",
"video_title": "Arnold Schwarzenegger on Son-in-law Chris Pratt, Pranking Sylvester Stallone & Terminator’s Return",
"fmt_id": "18",
"fmt_quality": "640x360"
}
]
But when I try and loop through each entry with fillInOptions(), my loop is never completed because the length is apparently zero. However, when I dump the array using console.log() it tells me the length is 2, and displays the above. I need to be able to add each option to my dropdown.
Thankyou!
UPDATE: Added full code, sorry!
It looks like your .forEach() is the root of the problem. The parameters of a forEach are currentValue, index like this: array.forEach(function(currentValue, index) {}); but it looks like you're using them in the opposite way
Try rewriting that iteration to this:
ytFill.forEach(function(v, i) {
console.log(i);
ytdlOptions.append(new Option(v.fmt_quality, v.fmt_id));
});
Notice the difference in the order of v and i in the parameters.
I have an array of objects and want to create another array of objects based on.
I want to check if an object is repeated just want to show the count, otherwise show the object itself with count = 1.
<!-- I have an array-->
var arr =[{name:"coke",price:20},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250}];
// I want to create another array based on "arr" like the one below
var test =[{name:"coke",price:20,count:3},{name:"kabab",price:20,count:1}];
//Any hint please
This may help you. This answer considers name or some identifier will be unique for each object.
counter = {}
var arr = [{
name: "coke",
price: 20
}, {
name: "coke",
price: 20
}, {
name: "coke",
price: 20
}, {
name: "kabab",
price: 250
}];
var obj = {};
var counter = {}
for (var i = 0, len = arr.length; i < len; i++) {
obj[arr[i]['name']] = arr[i];
counter[arr[i]['name']] = (counter[arr[i]['name']] || 0) + 1
}
newArr = new Array();
for (var key in obj){
newArr.push(extend( obj[key], {count:counter[key]}));
}
function extend(a, b){
for(var key in b)
if(b.hasOwnProperty(key))
a[key] = b[key];
return a;
}
console.log(newArr)
var arr =[{name:"coke",price:20},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250}];
var countNameMapping = {}, finalArr = [];
var arrLength = arr.length;
for(i=0; i<arrLength; i++){
var tempObj = {name:arr[i], price:arr[i].price, occurance:1};
var productName = arr[i].name;
if(countNameMapping[productName] === undefined){
countNameMapping[productName] = tempObj;
}else{
countNameMapping[productName].occurance += 1;
}
}
for(var k in countNameMapping){
finalArr.push(countNameMapping[k])
}
console.log(finalArr );
You can try this one:
var arr =[{name:"coke",price:20},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250}];
var result = [];
arr.map(function(arrObject) {
if (result.length > 0) {
result.map(function(resultObject) {
if (resultObject.name != arrObject.name) {
arrObject.count = 1;
result.push(arrObject);
} else {
resultObject.count++;
}
})
} else {
arrObject.count = 1;
result.push(arrObject);
}
})
console.log(result);
This will provide the result you are looking for:
var arr =[{name:"coke",price:20},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250}];
var map = arr.reduce((accum, item) => {
var obj = accum.get(item.name) || Object.assign({}, item, {count:0});
obj.count++;
return accum.set(item.name, obj);
}, new Map());
var res = [...map.values()];
More or less...
var arr = [{
name: "coke",
price: 20
}, {
name: "coke",
price: 20
}, {
name: "coke",
price: 20
}, {
name: "kabab",
price: 250
}];
// I want to create another array based on "arr" like the one below
// var test =[{name:"coke",price:20,count:3},{name:"kabab",price:20,count:1}];
var count = {};
var test = [];
for (var i = 0, len = arr.length; i < len; i++) {
var id = JSON.stringify(arr[i]);
if (count.hasOwnProperty(id)) {
count[id].count++;
} else {
test.push(arr[i]); // Data contamination. Too lazy to copy object
count[id] = test[test.length - 1]; // Could be better.
count[id].count = 1;
}
}
console.log(test);
This is probably what are you looking for:
How does it work?
First, your array arr will use a forEach loop to find each object and if if new you will add it to the results array. The method isNew() will return true if the object is new.
For each new object founded you will count the number of occurrences using findOccurrences() To reduce the number of "loops" you will slice the array according to the index. So you don't need to search again over the already processed data.
So now you can build an new object, using the name, price and count.
Finally, you can push() the new object to the results array.
var arr =[{name:"coke",price:20},{price:20,name:"coke"},{name:"coke",price:20},{name:"kabab",price:250}];
var results = [];
var index = 0;
var originalDiv = document.getElementById('original');
var resultsDiv = document.getElementById('results');
arr.forEach(function(obj) {
if (isNew(obj)) {
var counter = findOccurrences(obj, arr.slice(index, arr.length));
var newObj = {
name: obj.name,
price: obj.price,
count: counter
}
results.push(newObj);
}
index++;
});
printArray(arr, originalDiv);
printArray(results, resultsDiv);
function isNew(newObj) {
var wasFound = true;
if (typeof results != "undefined" && results != null && results.length > 0) {
results.forEach(function(obj) {
if (newObj.name === obj.name && newObj.price === obj.price) {
return false;
} else {
wasFound = false;
}
});
return !wasFound;
} else {
return true;
}
}
function findOccurrences(newObj, objects) {
var count = 0;
if (typeof objects != "undefined" && objects != null && objects.length > 0) {
objects.forEach(function(obj) {
if (newObj.name === obj.name && newObj.price === obj.price) {
count++;
}
});
}
return count;
}
function printArray(objects, div) {
var count = 0;
if (typeof objects != "undefined" && objects != null && objects.length > 0) {
objects.forEach(function(obj) {
var newElement = document.createElement('p');
newElement.innerHTML = 'item ' + count + ': ';
Object.keys(obj).forEach(function(key) {
newElement.innerHTML += key + ': ' + obj[key] + ', ';
});
newElement.innerHTML = newElement.innerHTML.slice(0, -2);
div.appendChild(newElement);
count++;
});
}
}
<div id="original"><p>Original Array</p></div>
<div id="results"><p>Results Array</p></div>
Update:
More optimization.
var arr =[{name:"coke",price:20},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250},{name:"coke",price:20},{name:"coke",price:20},{name:"kabab",price:250}];
var accumulator = {};
var results = [];
var index = 0;
var originalDiv = document.getElementById('original');
var resultsDiv = document.getElementById('results');
String.prototype.hashCode = function() {
var hash = 0;
if (this.length == 0) return hash;
for (i = 0; i < this.length; i++) {
var char = this.charCodeAt(i);
hash = ((hash << 5) - hash) + char;
hash |= 0; // Convert to 32bit integer
}
var c = (hash & 0x0FFFFFFF)
.toString(16)
.toUpperCase();
return '0000000'.substring(0, 7 - c.length) + c;
};
arr.forEach(function(obj) {
var id = JSON.stringify(obj).hashCode();
console.log(id);
if (accumulator.hasOwnProperty(id)) {
accumulator[id].count++;
} else {
results.push(obj);
accumulator[id] = results[results.length - 1];
accumulator[id].count = 1;
}
});
printArray(arr, originalDiv);
printArray(results, resultsDiv);
function printArray(objects, div) {
var count = 0;
if (typeof objects != "undefined" && objects != null && objects.length > 0) {
objects.forEach(function(obj) {
var newElement = document.createElement('p');
newElement.innerHTML = 'item ' + count + ': ';
Object.keys(obj).forEach(function(key) {
newElement.innerHTML += key + ': ' + obj[key] + ', ';
});
newElement.innerHTML = newElement.innerHTML.slice(0, -2);
div.appendChild(newElement);
count++;
});
}
}
<div id="original">
<p>Original Array</p>
</div>
<div id="results">
<p>Results Array</p>
</div>
Going to do my best at explaining what I am trying to do.
I have two models, mine and an api response I am receiving. When the items api response comes in, I need to map it to my model and inserts all the items. This is simple of course. Heres the issue, I need to do so without really knowing what I am dealing with. My code will be passed in two strings, one of my models mapping path and one of the api response mapping path.
Here are the two paths
var myPath = "outputModel.items[].uniqueName"
var apiPath = "items[].name"
Basically FOR all items in apiPath, push into items in myPath and set to uniqueName
What it comes down to is that my code has NO idea when two items need to be mapped, or even if they contain an array or simple field to field paths. They could even contain multiple arrays, like this:
******************** EXAMPLE *************************
var items = [
{
name: "Hammer",
skus:[
{num:"12345qwert"}
]
},
{
name: "Bike",
skus:[
{num:"asdfghhj"},
{num:"zxcvbn"}
]
},
{
name: "Fork",
skus:[
{num:"0987dfgh"}
]
}
]
var outputModel = {
storeName: "",
items: [
{
name: "",
sku:""
}
]
};
outputModel.items[].name = items[].name;
outputModel.items[].sku = items[].skus[].num;
************************ Here is the expected result of above
var result = {
storeName: "",
items: [
{
name: "Hammer",
sku:"12345qwert"
},
{
name: "Bike",
sku:"asdfghhj"
},
{
name: "Bike",
sku:"zxcvbn"
},
{
name: "Fork",
sku:"0987dfgh" }
]
};
I will be given a set of paths for EACH value to be mapped. In the case above, I was handed two sets of paths because I am mapping two values. It would have to traverse both sets of arrays to create the single array in my model.
Question - How can I dynamically detect arrays and move the data around properly no matter what the two model paths look like? Possible?
So you have defined a little language to define some data addressing and manipulation rules. Let's think about an approach which will allow you to say
access(apiPath, function(value) { insert(myPath, value); }
The access function finds all the required items in apiPath, then calls back to insert, which inserts them into myPath. Our job is to write functions which create the access and insert functions; or, you could say, "compile" your little language into functions we can execute.
We will write "compilers" called make_accessor and make_inserter, as follows:
function make_accessor(program) {
return function(obj, callback) {
return function do_segment(obj, segments) {
var start = segments.shift() // Get first segment
var pieces = start.match(/(\w+)(\[\])?/); // Get name and [] pieces
var property = pieces[1];
var isArray = pieces[2]; // [] on end
obj = obj[property]; // drill down
if (!segments.length) { // last segment; callback
if (isArray) {
return obj.forEach(callback);
} else {
return callback(obj);
}
} else { // more segments; recurse
if (isArray) { // array--loop over elts
obj.forEach(function(elt) { do_segment(elt, segments.slice()); });
} else {
do_segment(obj, segments.slice()); // scalar--continue
}
}
}(obj, program.split('.'));
};
}
We can now make an accessor by calling make_accessor('items[].name').
Next, let's write the inserter:
function make_inserter(program) {
return function(obj, value) {
return function do_segment(obj, segments) {
var start = segments.shift() // Get first segment
var pieces = start.match(/(\w+)(\[\])?/); // Get name and [] pieces
var property = pieces[1];
var isArray = pieces[2]; // [] on end
if (segments.length) { // more segments
if (!obj[property]) {
obj[property] = isArray ? [] : {};
}
do_segment(obj, segments.slice());
} else { // last segment
obj[property] = value;
}
}(obj, program.split('.'));
};
}
Now, you can express your whole logic as
access = make_accessor('items[].name');
insert = make_inserter('outputModel.items[].uniqueName');
access(apiPath, function(val) { insert(myPath, val); });
As mentioned in the comments, there is no strict definition of the input format, it is hard to do it with perfect error handling and handle all corner cases.
Here is my lengthy implementation that works on your sample, but might fail for some other cases:
function merge_objects(a, b) {
var c = {}, attr;
for (attr in a) { c[attr] = a[attr]; }
for (attr in b) { c[attr] = b[attr]; }
return c;
}
var id = {
inner: null,
name: "id",
repr: "id",
type: "map",
exec: function (input) { return input; }
};
// set output field
function f(outp, mapper) {
mapper = typeof mapper !== "undefined" ? mapper : id;
var repr = "f("+outp+","+mapper.repr+")";
var name = "f("+outp;
return {
inner: mapper,
name: name,
repr: repr,
type: "map",
clone: function(mapper) { return f(outp, mapper); },
exec:
function (input) {
var out = {};
out[outp] = mapper.exec(input);
return out;
}
};
}
// set input field
function p(inp, mapper) {
var repr = "p("+inp+","+mapper.repr+")";
var name = "p("+inp;
return {
inner: mapper,
name: name,
repr: repr,
type: mapper.type,
clone: function(mapper) { return p(inp, mapper); },
exec: function (input) {
return mapper.exec(input[inp]);
}
};
}
// process array
function arr(mapper) {
var repr = "arr("+mapper.repr+")";
return {
inner: mapper,
name: "arr",
repr: repr,
type: mapper.type,
clone: function(mapper) { return arr(mapper); },
exec: function (input) {
var out = [];
for (var i=0; i<input.length; i++) {
out.push(mapper.exec(input[i]));
}
return out;
}
};
}
function combine(m1, m2) {
var type = (m1.type == "flatmap" || m2.type == "flatmap") ? "flatmap" : "map";
var repr = "combine("+m1.repr+","+m2.repr+")";
return {
inner: null,
repr: repr,
type: type,
name: "combine",
exec:
function (input) {
var out1 = m1.exec(input);
var out2 = m2.exec(input);
var out, i, j;
if (m1.type == "flatmap" && m2.type == "flatmap") {
out = [];
for (i=0; i<out1.length; i++) {
for (j=0; j<out2.length; j++) {
out.push(merge_objects(out1[i], out2[j]));
}
}
return out;
}
if (m1.type == "flatmap" && m2.type != "flatmap") {
out = [];
for (i=0; i<out1.length; i++) {
out.push(merge_objects(out1[i], out2));
}
return out;
}
if (m1.type != "flatmap" && m2.type == "flatmap") {
out = [];
for (i=0; i<out2.length; i++) {
out.push(merge_objects(out2[i], out1));
}
return out;
}
return merge_objects(out1, out2);
}
};
}
function flatmap(mapper) {
var repr = "flatmap("+mapper.repr+")";
return {
inner: mapper,
repr: repr,
type: "flatmap",
name: "flatmap",
clone: function(mapper) { return flatmap(mapper); },
exec:
function (input) {
var out = [];
for (var i=0; i<input.length; i++) {
out.push(mapper.exec(input[i]));
}
return out;
}
};
}
function split(s, t) {
var i = s.indexOf(t);
if (i == -1) return null;
else {
return [s.slice(0, i), s.slice(i+2, s.length)];
}
}
function compile_one(inr, outr) {
inr = (inr.charAt(0) == ".") ? inr.slice(1, inr.length) : inr;
outr = (outr.charAt(0) == ".") ? outr.slice(1, outr.length) : outr;
var box = split(inr, "[]");
var box2 = split(outr, "[]");
var m, ps, fs, i, j;
if (box == null && box2 == null) { // no array!
m = id;
ps = inr.split(".");
fs = outr.split(".");
for (i=0; i<fs.length; i++) { m = f(fs[i], m); }
for (j=0; j<ps.length; j++) { m = p(ps[j], m); }
return m;
}
if (box != null && box2 != null) { // array on both sides
m = arr(compile_one(box[1], box2[1]));
ps = box[0].split(".");
fs = box[0].split(".");
for (i=0; i<fs.length; i++) { m = f(fs[i], m); }
for (j=0; j<ps.length; j++) { m = p(ps[j], m); }
return m;
}
if (box != null && box2 == null) { // flatmap
m = flatmap(compile_one(box[1], outr));
ps = box[0].split(".");
for (j=0; j<ps.length; j++) { m = p(ps[j], m); }
return m;
}
return null;
}
function merge_rules(m1, m2) {
if (m1 == null) return m2;
if (m2 == null) return m1;
if (m1.name == m2.name && m1.inner != null) {
return m1.clone(merge_rules(m1.inner, m2.inner));
} else {
return combine(m1, m2);
}
}
var input = {
store: "myStore",
items: [
{name: "Hammer", skus:[{num:"12345qwert"}]},
{name: "Bike", skus:[{num:"asdfghhj"}, {num:"zxcvbn"}]},
{name: "Fork", skus:[{num:"0987dfgh"}]}
]
};
var m1 = compile_one("items[].name", "items[].name");
var m2 = compile_one("items[].skus[].num", "items[].sku");
var m3 = compile_one("store", "storeName");
var m4 = merge_rules(m3,merge_rules(m1, m2));
var out = m4.exec(input);
alert(JSON.stringify(out));
I have borrowed earlier answer and made improvements so as to solve both your examples and this should be generic. Though if you plan to run this sequencially with 2 sets of inputs, then the behavior will be as I have outlined in my comments to your original question.
var apiObj = {
items: [{
name: "Hammer",
skus: [{
num: "12345qwert"
}]
}, {
name: "Bike",
skus: [{
num: "asdfghhj"
}, {
num: "zxcvbn"
}]
}, {
name: "Fork",
skus: [{
num: "0987dfgh"
}]
}]
};
var myObj = { //Previously has values
storeName: "",
items: [{
uniqueName: ""
}],
outputModel: {
items: [{
name: "Hammer"
}]
}
};
/** Also works with this **
var myPath = "outputModel.items[].uniqueName";
var apiPath = "items[].name";
*/
var myPath = "outputModel.items[].sku";
var apiPath = "items[].skus[].num";
function make_accessor(program) {
return function (obj, callback) {
(function do_segment(obj, segments) {
var start = segments.shift() // Get first segment
var pieces = start.match(/(\w+)(\[\])?/); // Get name and [] pieces
var property = pieces[1];
var isArray = pieces[2]; // [] on end
obj = obj[property]; // drill down
if (!segments.length) { // last segment; callback
if (isArray) {
return obj.forEach(callback);
} else {
return callback(obj);
}
} else { // more segments; recurse
if (isArray) { // array--loop over elts
obj.forEach(function (elt) {
do_segment(elt, segments.slice());
});
} else {
do_segment(obj, segments.slice()); // scalar--continue
}
}
})(obj, program.split('.'));
};
}
function make_inserter(program) {
return function (obj, value) {
(function do_segment(obj, segments) {
var start = segments.shift() // Get first segment
var pieces = start.match(/(\w+)(\[\])?/); // Get name and [] pieces
var property = pieces[1];
var isArray = pieces[2]; // [] on end
if (segments.length) { // more segments
if (!obj[property]) {
obj[property] = isArray ? [] : {};
}
do_segment(obj[property], segments.slice());
} else { // last segment
if (Array.isArray(obj)) {
var addedInFor = false;
for (var i = 0; i < obj.length; i++) {
if (!(property in obj[i])) {
obj[i][property] = value;
addedInFor = true;
break;
}
}
if (!addedInFor) {
var entry = {};
entry[property] = value;
obj.push(entry);
}
} else obj[property] = value;
}
})(obj, program.split('.'));
};
}
access = make_accessor(apiPath);
insert = make_inserter(myPath);
access(apiObj, function (val) {
insert(myObj, val);
});
console.log(myObj);
(old solution: https://jsfiddle.net/d7by0ywy/):
Here is my new generalized solution when you know the two objects to process in advance (called inp and out here). If you don't know them in advance you can use the trick in the old solution to assign the objects on both sides of = to inp and out (https://jsfiddle.net/uxdney3L/3/).
Restrictions: There has to be the same amount of arrays on both sides and an array has to contain objects. Othewise it would be ambiguous, you would have to come up with a better grammar to express rules (or why don't you have functions instead of rules?) if you want it to be more sophisticated.
Example of ambiguity: out.items[].sku=inp[].skus[].num Do you assign an array of the values of num to sku or do you assign an array of objects with the num property?
Data:
rules = [
'out.items[].name=inp[].name',
'out.items[].sku[].num=inp[].skus[].num'
];
inp = [{
'name': 'Hammer',
'skus':[{'num':'12345qwert','test':'ignore'}]
},{
'name': 'Bike',
'skus':[{'num':'asdfghhj'},{'num':'zxcvbn'}]
},{
'name': 'Fork',
'skus':[{'num':'0987dfgh'}]
}];
Program:
function process() {
if (typeof out == 'undefined') {
out = {};
}
var j, r;
for (j = 0; j < rules.length; j++) {
r = rules[j].split('=');
if (r.length != 2) {
console.log('invalid rule: symbol "=" is expected exactly once');
} else if (r[0].substr(0, 3) != 'out' || r[1].substr(0, 3) != 'inp') {
console.log('invalid rule: expected "inp...=out..."');
} else {
processRule(r[0].substr(3).split('[]'), r[1].substr(3).split('[]'), 0, inp, out);
}
}
}
function processRule(l, r, n, i, o) { // left, right, index, in, out
var t = r[n].split('.');
for (var j = 0; j < t.length; j++) {
if (t[j] != '') {
i = i[t[j]];
}
}
t = l[n].split('.');
if (n < l.length - 1) {
for (j = 0; j < t.length - 1; j++) {
if (t[j] != '') {
if (typeof o[t[j]] == 'undefined') {
o[t[j]] = {};
}
o = o[t[j]];
}
}
if (typeof o[t[j]] == 'undefined') {
o[t[j]] = [];
}
o = o[t[j]];
for (j = 0; j < i.length; j++) {
if (typeof o[j] == 'undefined') {
o[j] = {};
}
processRule(l, r, n + 1, i[j], o[j]);
}
} else {
for (j = 0; j < t.length - 1; j++) {
if (t[j] != '') {
if (typeof o[t[j]] == 'undefined') {
o[t[j]] = {};
}
o = o[t[j]];
}
}
o[t[j]] = i;
}
}
process();
console.log(out);
Well, an interesting problem. Programmatically constructing nested objects from a property accessor string (or the reverse) isn't much of a problem, even doing so with multiple descriptors in parallel. Where it does get complicated are arrays, which require iteration; and that isn't as funny any more when it gets to different levels on setter and getter sides and multiple descriptor strings in parallel.
So first we need to distinguish the array levels of each accessor description in the script, and parse the text:
function parse(script) {
return script.split(/\s*[;\r\n]+\s*/g).map(function(line) {
var assignment = line.split(/\s*=\s*/);
return assignment.length == 2 ? assignment : null; // console.warn ???
}).filter(Boolean).map(function(as) {
as = as.map(function(accessor) {
var parts = accessor.split("[]").map(function(part) {
return part.split(".");
});
for (var i=1; i<parts.length; i++) {
// assert(parts[i][0] == "")
var prev = parts[i-1][parts[i-1].length-1];
parts[i][0] = prev.replace(/s$/, ""); // singular :-)
}
return parts;
});
if (as[0].length == 1 && as[1].length > 1) // getter contains array but setter does not
as[0].unshift(["output"]); // implicitly return array (but better throw an error)
return {setter:as[0], getter:as[1]};
});
}
With that, the textual input can be made into a usable data structure, and now looks like this:
[{"setter":[["outputModel","items"],["item","name"]],
"getter":[["items"],["item","name"]]},
{"setter":[["outputModel","items"],["item","sku"]],
"getter":[["items"],["item","skus"],["sku","num"]]}]
The getters already transform nicely into nested loops like
for (item of items)
for (sku of item.skus)
… sku.num …;
and that's exactly where we are going to. Each of those rules is relatively easy to process, copying properties on objects and iterating array for array, but here comes our most crucial issue: We have multiple rules. The basic solution when we deal with iterating multiple arrays is to create their cartesian product and this is indeed what we will need. However, we want to restrict this a lot - instead of creating every combination of all names and all nums in the input, we want to group them by the item that they come from.
To do so, we'll build some kind of prefix tree for our output structure that'll contain generators of objects, each of those recursivley being a tree for the respective output substructure again.
function multiGroupBy(arr, by) {
return arr.reduce(function(res, x) {
var p = by(x);
(res[p] || (res[p] = [])).push(x);
return res;
}, {});
}
function group(rules) {
var paths = multiGroupBy(rules, function(rule) {
return rule.setter[0].slice(1).join(".");
});
var res = [];
for (var path in paths) {
var pathrules = paths[path],
array = [];
for (var i=0; i<pathrules.length; i++) {
var rule = pathrules[i];
var comb = 1 + rule.getter.length - rule.setter.length;
if (rule.setter.length > 1) // its an array
array.push({
generator: rule.getter.slice(0, comb),
next: {
setter: rule.setter.slice(1),
getter: rule.getter.slice(comb)
}
})
else if (rule.getter.length == 1 && i==0)
res.push({
set: rule.setter[0],
get: rule.getter[0]
});
else
console.error("invalid:", rule);
}
if (array.length)
res.push({
set: pathrules[0].setter[0],
cross: product(array)
});
}
return res;
}
function product(pathsetters) {
var groups = multiGroupBy(pathsetters, function(pathsetter) {
return pathsetter.generator[0].slice(1).join(".");
});
var res = [];
for (var genstart in groups) {
var creators = groups[genstart],
nexts = [],
nests = [];
for (var i=0; i<creators.length; i++) {
if (creators[i].generator.length == 1)
nexts.push(creators[i].next);
else
nests.push({path:creators[i].path, generator: creators[i].generator.slice(1), next:creators[i].next});
}
res.push({
get: creators[0].generator[0],
cross: group(nexts).concat(product(nests))
});
}
return res;
}
Now, our ruleset group(parse(script)) looks like this:
[{
"set": ["outputModel","items"],
"cross": [{
"get": ["items"],
"cross": [{
"set": ["item","name"],
"get": ["item","name"]
}, {
"get": ["item","skus"],
"cross": [{
"set": ["item","sku"],
"get": ["sku","num"]
}]
}]
}]
}]
and that is a structure we can actually work with, as it now clearly conveys the intention on how to match together all those nested arrays and the objects within them.
Let's dynamically interpret this, building an output for a given input:
function transform(structure, input, output) {
for (var i=0; i<structure.length; i++) {
output = assign(output, structure[i].set.slice(1), getValue(structure[i], input));
}
return output;
}
function retrieve(val, props) {
return props.reduce(function(o, p) { return o[p]; }, val);
}
function assign(obj, props, val) {
if (!obj)
if (!props.length) return val;
else obj = {};
for (var j=0, o=obj; j<props.length-1 && o!=null && o[props[j]]; o=o[props[j++]]);
obj[props[j]] = props.slice(j+1).reduceRight(function(val, p) {
var o = {};
o[p] = val;
return o;
}, val);
return obj;
}
function getValue(descriptor, input) {
if (descriptor.get) // && !cross
return retrieve(input, descriptor.get.slice(1));
var arr = [];
descriptor.cross.reduce(function horror(next, d) {
if (descriptor.set)
return function (inp, cb) {
next(inp, function(res){
cb(assign(res, d.set.slice(1), getValue(d, inp)));
});
};
else // its a crosser
return function(inp, cb) {
var g = retrieve(inp, d.get.slice(1)),
e = d.cross.reduce(horror, next)
for (var i=0; i<g.length; i++)
e(g[i], cb);
};
}, function innermost(inp, cb) {
cb(); // start to create an item
})(input, function(res) {
arr.push(res); // store the item
});
return arr;
}
And this does indeed work with
var result = transform(group(parse(script)), items); // your expected result
But we can do better, and much more performant:
function compile(structure) {
function make(descriptor) {
if (descriptor.get)
return {inputName: descriptor.get[0], output: descriptor.get.join(".") };
var outputName = descriptor.set[descriptor.set.length-1];
var loops = descriptor.cross.reduce(function horror(next, descriptor) {
if (descriptor.set)
return function(it, cb) {
return next(it, function(res){
res.push(descriptor)
return cb(res);
});
};
else // its a crosser
return function(it, cb) {
var arrName = descriptor.get[descriptor.get.length-1],
itName = String.fromCharCode(it);
var inner = descriptor.cross.reduce(horror, next)(it+1, cb);
return {
inputName: descriptor.get[0],
statement: (descriptor.get.length>1 ? "var "+arrName+" = "+descriptor.get.join(".")+";\n" : "")+
"for (var "+itName+" = 0; "+itName+" < "+arrName+".length; "+itName+"++) {\n"+
"var "+inner.inputName+" = "+arrName+"["+itName+"];\n"+
inner.statement+
"}\n"
};
};
}, function(_, cb) {
return cb([]);
})(105, function(res) {
var item = joinSetters(res);
return {
inputName: item.inputName,
statement: (item.statement||"")+outputName+".push("+item.output+");\n"
};
});
return {
statement: "var "+outputName+" = [];\n"+loops.statement,
output: outputName,
inputName: loops.inputName
};
}
function joinSetters(descriptors) {
if (descriptors.length == 1 && descriptors[0].set.length == 1)
return make(descriptors[0]);
var paths = multiGroupBy(descriptors, function(d){ return d.set[1] || console.error("multiple assignments on "+d.set[0], d); });
var statements = [],
inputName;
var props = Object.keys(paths).map(function(p) {
var d = joinSetters(paths[p].map(function(d) {
var names = d.set.slice(1);
names[0] = d.set[0]+"_"+names[0];
return {set:names, get:d.get, cross:d.cross};
}));
inputName = d.inputName;
if (d.statement)
statements.push(d.statement)
return JSON.stringify(p) + ": " + d.output;
});
return {
inputName: inputName,
statement: statements.join(""),
output: "{"+props.join(",")+"}"
};
}
var code = joinSetters(structure);
return new Function(code.inputName, code.statement+"return "+code.output+";");
}
So here is what you will get in the end:
> var example = compile(group(parse("outputModel.items[].name = items[].name;outputModel.items[].sku = items[].skus[].num;")))
function(items) {
var outputModel_items = [];
for (var i = 0; i < items.length; i++) {
var item = items[i];
var skus = item.skus;
for (var j = 0; j < skus.length; j++) {
var sku = skus[j];
outputModel_items.push({"name": item.name,"sku": sku.num});
}
}
return {"items": outputModel_items};
}
> var flatten = compile(group(parse("as[]=bss[][]")))
function(bss) {
var as = [];
for (var i = 0; i < bss.length; i++) {
var bs = bss[i];
for (var j = 0; j < bs.length; j++) {
var b = bs[j];
as.push(b);
}
}
return as;
}
> var parallelRecords = compile(group(parse("x.as[]=y[].a; x.bs[]=y[].b")))
function(y) {
var x_as = [];
for (var i = 0; i < y.length; i++) {
var y = y[i];
x_as.push(y.a);
}
var x_bs = [];
for (var i = 0; i < y.length; i++) {
var y = y[i];
x_bs.push(y.b);
}
return {"as": x_as,"bs": x_bs};
}
And now you can easily pass your input data to that dynamically created function and it will be transformed quite fast :-)
i have a bunch of options in this select, each with values like:
context|cow
context|test
thing|1
thing|5
thing|27
context|beans
while looping through the options, I want to build an array that checks to see if keys exist, and if they don't they make the key then append the value. then the next loop through, if the key exists, add the next value, comma separated.
the ideal output would be:
arr['context'] = 'cow,test,beans';
arr['thing'] = '1,5,27';
here's what i have so far, but this isn't a good strategy to build the values..
function sift(select) {
vals = [];
$.each(select.options, function() {
var valArr = this.value.split('|');
var key = valArr[0];
var val = valArr[1];
if (typeof vals[key] === 'undefined') {
vals[key] = [];
}
vals[key].push(val);
});
console.log(vals);
}
Existing code works by changing
vals=[];
To
vals={};
http://jsfiddle.net/BrxuM/
function sift(select) {
var vals = {};//notice I made an object, not an array, this is to create an associative array
$.each(select.options, function() {
var valArr = this.value.split('|');
if (typeof vals[valArr[0]] === 'undefined') {
vals[valArr[0]] = '';
} else {
vals[valArr[0]] += ',';
}
vals[valArr[0]] += valArr[1];
});
}
Here is a demo: http://jsfiddle.net/jasper/xtfm2/1/
How about an extensible, reusable, encapsulated solution:
function MyOptions()
{
var _optionNames = [];
var _optionValues = [];
function _add(name, value)
{
var nameIndex = _optionNames.indexOf(name);
if (nameIndex < 0)
{
_optionNames.push(name);
var newValues = [];
newValues.push(value);
_optionValues.push(newValues);
}
else
{
var values = _optionValues[nameIndex];
values.push(value);
_optionValues[nameIndex] = values;
}
};
function _values(name)
{
var nameIndex = _optionNames.indexOf(name);
if (nameIndex < 0)
{
return [];
}
else
{
return _optionValues[nameIndex];
}
};
var public =
{
add: _add,
values: _values
};
return public;
}
usage:
var myOptions = MyOptions();
myOptions.add("context", "cow");
myOptions.add("context","test");
myOptions.add("thing","1");
myOptions.add("thing","5");
myOptions.add("thing","27");
myOptions.add("context","beans");
console.log(myOptions.values("context").join(","));
console.log(myOptions.values("thing").join(","));
working example: http://jsfiddle.net/Zjamy/
I guess this works, but if someone could optimize it, I'd love to see.
function updateSiftUrl(select) { var
vals = {};
$.each(select.options, function() {
var valArr = this.value.split('|');
var key = valArr[0];
var val = valArr[1];
if (typeof vals[key] === 'undefined') {
vals[key] = val;
return;
}
vals[key] = vals[key] +','+ val;
});
console.log(vals);
}
Would something like this work for you?
$("select#yourselect").change(function(){
var optionArray =
$(":selected", $(this)).map(function(){
return $(this).val();
}).get().join(", ");
});
If you've selected 3 options, optionArray should contain something like option1, option2, option3.
Well, you don't want vals[key] to be an array - you want it to be a string. so try doing
if (typeof vals[key] === 'undefined') {
vals[key] = ';
}
vals[key] = vals[key] + ',' + val;