i have a really big collection of objects that i want to search through.
The array have > 60.000 items and the search performance can be really slow from time to time.
One object in that array looks like this:
{
"title": "title"
"company": "abc company"
"rating": 13 // internal rating based on comments and interaction
...
}
I want to search for the title and the company info and order that by the rating of the items.
This is what my search currently look like:
onSearchInput(searchTerm) {
(<any>window).clearTimeout(this.searchInputTimeout);
this.searchInputTimeout = window.setTimeout(() => {
this.searchForFood(searchTerm);
}, 500);
}
searchForFood(searchTerm) {
if (searchTerm.length > 1) {
this.searchResults = [];
this.foodList.map(item => {
searchTerm.split(' ').map(searchTermPart => {
if (item.title.toLowerCase().includes(searchTermPart.toLowerCase())
|| item.company.toLowerCase().includes(searchTermPart.toLowerCase())) {
this.searchResults.push(item);
}
});
});
this.searchResults = this.searchResults.sort(function(a, b) {
return a.rating - b.rating;
}).reverse();
} else {
this.searchResults = [];
}
}
Question: Is there any way to improve the search logic and performance wise?
A bunch of hints:
It's a bit excessive to put searching through 60,000 items on the front-end. Any way you can perform part of the search on the back-end? If you really must do it on the front-end considering searching in chunks of e.g. 10,000 and then using a setImmediate() to perform the next part of the search so the user's browser won't completely freeze during processing time.
Do the splitting and lowercasing of the search term outside of the loop.
map() like you're using it is weird as you don't use the return value. Better to use forEach(). Better still, is use filter() to get the items that match.
When iterating over the search terms, use some() (as pointed out in the comments) as it's an opportunity to early return.
sort() mutates the original array so you don't need to re-assign it.
sort() with reverse() is usually a smell. Instead, swap the sides of your condition to be b - a.
At this scale, it may make sense to do performance tests with includes(), indexOf(), roll-your-own-for-loop, match() (can almost guarantee it will be slower though)
Alex's suggestions are good. My only suggestion would be, if you could afford to pre-process the data during idle time (preferably don't hold up first render or interaction) you could process the data into a modified prefix trie. That would let you search for the items in O(k) time where k is the length of the search term (right now you are searching in O(kn) time because you look at every item and then do an includes which takes k time (it's actually a little worse because of the toLowerCase's but I don't want to get into the weeds of it).
If you aren't familiar with what a trie is, hopefully the code below gives you the idea or you can search for information with your search engine of choice. It's basically a mapping of characters in a string in nested hash maps.
Here's some sample code of how you might construct the trie:
function makeTries(data){
let companyTrie = {};
let titleTrie = {};
data.forEach(item => {
addToTrie(companyTrie, item.company, item, 0);
addToTrie(titleTrie, item.title, item, 0);
});
return {
companyTrie,
titleTrie
}
}
function addToTrie(trie, str, item, i){
trie.data = trie.data || [];
trie.data.push(item);
if(i >= str.length)
return;
if(! trie[str[i]]){
trie[str[i]] = {};
}
addToTrie(trie[str[i]], str, item, ++i);
}
function searchTrie(trie, term){
if(trie == undefined)
return [];
if(term == "")
return trie.data;
return searchTrie(trie[term[0]], term.substring(1));
}
var testData = [
{
company: "abc",
title: "def",
rank: 5
},{
company: "abd",
title: "deg",
rank: 5
},{
company: "afg",
title: "efg",
rank: 5
},{
company: "afgh",
title: "efh",
rank: 5
},
];
const tries = makeTries(testData);
console.log(searchTrie(tries.companyTrie, "afg"));
Related
I'm using vuetify's combobox to search for users and build a list.
<v-combobox
v-model="event.user"
:items="usersData"
label="Search speaker list"
:search-input.sync="searchUser"
return-object
item-value="id"
item-text="name"
>
</v-combobox>
I have an addSpeaker method. My question is what is the best way to check if a user has already been added and ideally prevent them from being added again?
addSpeaker () {
const newSpeaker = {
id: Date.now(),
name: this.event.user.name,
company: this.event.user.company,
jobTitle: this.event.user.jobTitle
}
this.speakers.push(newSpeaker)
this.event.user = ''
}
If this.speakers is an Array, as is implied by your use of this.speakers.push, the only way to check if a user is already in the array is to iterate over the whole array and compare the "nominated" speaker with each element.
On average, you will make n/2 comparisons for an array with n elements, and at worst n comparisons. This may be acceptable if your array never gets too large. How many speakers will there be? 10? 100? 10,000? The cost of 10 comparisons is probably fine.
With an Array you can use the Array.find() method to check:
var speakers = [];
speakers.push({id: "speakerId-17", last: "Smith", first: "John", jobTitle: "Guru", company: "Acme Corp"});
speakers.push({id: "speakerId-8", last: "Jones", first: "Laura", jobTitle: "Guru", company: "Ajax Corp"});
if (speakers.find(o => o.id==='speakerId-8')) {
console.log("speakerId-8 is already in speakers list, Don't add");
}
else {
console.log("Add speakerId-8");
}
if (speakers.find(o => o.id==='speakerId-11')) {
console.log("speakerId-11 is already in speakers list, Don't add");
}
else {
console.log("Add speakerId-11");
}
This would make your code something like this:
if (! this.speakers.find(o => o.id === newSpeaker.id)) {
this.speakers.push(newSpeaker)
}
The alternative is to somehow index the speakers already added, and a Map would be useful for this.
You would make this.speakers a Map instead of an Array, and add a speaker to the map when chosen using the .set() method, and can check if they are already in the map with .has().
A simple example, using hard-coded elements — you would of course be using your variables:
var /*this.*/speakers = new Map();
// ...
if (! speakers.has('speakerId-17')) {
speakers.set('speakerId-17',
{ 'last':'Smith',
'first':'John',
'jobTitle':'Guru',
'company':'Acme Corp' }
);
}
I'm a backend dev moved recently onto js side. I was going through a tutorial and came across the below piece of code.
clickCreate: function(component, event, helper) {
var validExpense = component.find('expenseform').reduce(function (validSoFar, inputCmp) {
// Displays error messages for invalid fields
inputCmp.showHelpMessageIfInvalid();
return validSoFar && inputCmp.get('v.validity').valid;
}, true);
// If we pass error checking, do some real work
if(validExpense){
// Create the new expense
var newExpense = component.get("v.newExpense");
console.log("Create expense: " + JSON.stringify(newExpense));
helper.createExpense(component, newExpense);
}
}
Here I tried to understand a lot on what's happening, there is something called reduce and another thing named validSoFar. I'm unable to understand what's happening under the hood. :-(
I do get the regular loops stuff as done in Java.
Can someone please shower some light on what's happening here. I should be using this a lot in my regular work.
Thanks
The reduce function here is iterating through each input component of the expense form and incrementally mapping to a boolean. If you have say three inputs each with a true validity, the reduce function would return:
true && true where the first true is the initial value passed into reduce.
true && true and where the first true here is the result of the previous result.
true && true
At the end of the reduction, you're left with a single boolean representing the validity of the entire, where by that if just a single input component's validity is false, the entire reduction will amount to false. This is because validSoFar keeps track of the overall validity and is mutated by returning the compound of the whether the form is valid so far and the validity of the current input in iteration.
This is a reasonable equivalent:
var validExpense = true;
var inputCmps = component.find('expenseform')
for (var i = 0; i < inputCmps.length; i++) {
// Displays error messages for invalid fields
inputCmp.showHelpMessageIfInvalid();
if (!inputCmp.get('v.validity').valid) {
validExpense = false;
}
}
// Now we can use validExpense
This is a somewhat strange use of reduce, to be honest, because it does more than simply reducing a list to a single value. It also produces side effects (presumably) in the call to showHelpMessageIfInvalid().
The idea of reduce is simple. Given a list of values that you want to fold down one at a time into a single value (of the same or any other type), you supply a function that takes the current folded value and the next list value and returns a new folded value, and you supply an initial folded value, and reduce combines them by calling the function with each successive list value and the current folded value.
So, for instance,
var items = [
{name: 'foo', price: 7, quantity: 3},
{name: 'bar', price: 5, quantity: 5},
{name: 'baz', price: 19, quantity: 1}
]
const totalPrice = items.reduce(
(total, item) => total + item.price * item.quantity, // folding function
0 // initial value
); //=> 65
It does not make sense to use reduce there and have side effects in the reduce. Better use Array.prototype.filter to get all invalid expense items.
Then use Array.prototype.forEach to produce side effect(s) for each invalid item. You can then check the length of invalid expense items array to see it your input was valid:
function(component, event, helper) {
var invalidExpenses = component.find('expenseform').filter(
function(ex){
//return not valid (!valid)
return !ex.get('v.validity').valid
}
);
invalidExpenses.forEach(
//use forEach if you need a side effect for each thing
function(ex){
ex.showHelpMessageIfInvalid();
}
);
// If we pass error checking, do some real work
if(invalidExpenses.length===0){//no invalid expense items
// Create the new expense
var newExpense = component.get("v.newExpense");
console.log("Create expense: " + JSON.stringify(newExpense));
helper.createExpense(component, newExpense);
}
}
The mdn documentation for Array.prototype.reduce has a good description and examples on how to use it.
It should take an array of things and return one other thing (can be different type of thing). But you won't find any examples there where side effects are initiated in the reducer function.
Quick question following up my response from this post:
dc.js Box plot reducer using two groups
Just trying to fully get my head around reducers and how to filter and collect data so I'll step through my understanding first.
Data Format:
{
"SSID": "eduroam",
"identifier": "Client",
"latitude": 52.4505,
"longitude": -1.9361,
"mac": "dc:d9:16:##:##:##",
"packet": "PR-REQ",
"timestamp": "2018-07-10 12:25:26",
"vendor": "Huawei Technologies Co.Ltd"
}
(1) Using the following should result in an output array of key value pairs (Key MAC Address & Value Count of networks connected to):
var MacCountsGroup = mac.group().reduce(
function (p, v) {
p[v.mac] = (p[v.mac] || 0) + v.counter;
return p;
},
function (p, v) {
p[v.mac] -= v.counter;
return p;
},
function () {
return {}; // KV Pair of MAC -> Count
}
);
(2) Then in order to use the object this must be passed flattened so it can be passed to a chart as follows:
function flatten_object_group(group) {
return {
all: function () {
return group.all().map(function (kv) {
return {
key: kv.key,
value: Object.values(kv.value).filter(function (v) {
return v > 0;
})
};
});
}
};
}
var connectionsGroup = flatten_object_group(MacCountsGroup);
(3) Then I pass mac as a piechart dimension & connectionsGroup as the group. This gives a chart back a chart with roughly 50,000 slices based on my dataset.
var packetPie = dc.pieChart("#packetPie");
packetPie
.height(495)
.width(350)
.radius(180)
.renderLabel(true)
.transitionDuration(1000)
.dimension(mac)
.ordinalColors(['#07453E', '#145C54', '#36847B'])
.group(connectionsGroup);
This works A'OK and I follow up to this point.
(4) Now I want to group by the values given out by the first reducer, i.e I want to combine all of the mac addresses with 1 network connection, 2 network connections and so on as slices.
How would this be done as a dimension of "Network connections"? How can I produce this summarized data which doesn't exist in my source data and is generated from mac?
Or would this require an intermediate function between the first reducer and flattening to combine all of the values from the first reducer?
You don't need to do all of that to get a pie chart of mac addresses.
There are a few faulty understandings in points 1-3, which I guess I'll address first. It looks like you copy and pasted code from the previous question, so I'm not really sure if this helps.
(1) If you have a dimension of mac addresses, reducing it like this won't have any further effect. The original idea was to dimension/group by vendor and then reduce counts for each mac address. This reduction will group by mac address and then further count instances of each mac address within each bin, so it's just an object with one key. It will produce a map of key value pairs like
{key: 'MAC-123', value: {'MAC-123': 12}}
(2) This will flatten the object within the values, dropping the keys and producing just an array of counts
{key: 'MAC-123', value: [12]}
(3) Since the pie chart is expecting simple key/value pairs with the value being a number, it is probably unhappy with getting values like the array [12]. The values are probably coerced to NaN.
(4) Okay, here's the real question, and it's actually not as easy as your previous question. We got off easy with the box plot because the "dimension" (in crossfilter terms, the keys you filter and group on) existed in your data.
Let's forget the false lead in points 1-3 above, and start from first principles.
There is no way to look at an individual row of your data and determine, without looking at anything else, if it belongs to the category "has 1 connection", "has 2 connections", etc. Assuming you want to be able to click on slices in the pie chart and filter all the data, we'll have to find another way to implement that.
But first let's look at how to produce a pie chart of "number of network connections". That's a little bit easier, but as far as I know, it does require a true "double reduce".
If we use the default reduction on the mac dimension, we'll get an array of key/value pairs, where the key is a mac address, and the value is the number of connections for that address:
[
{
"key": "1c:b7:2c:48",
"value": 8
},
{
"key": "1c:b7:be:ef",
"value": 3
},
{
"key": "6c:17:79:03",
"value": 2
},
...
How do we now produce a key/value array where the key is number of connections, and the value is the array of mac addresses for that number of connections?
Sounds like a job for the lesser-known Array.reduce. This function is the likely inspiration for crossfilter's group.reduce(), but it's a bit simpler: it just walks through an array, combining each value with the result of the last. It's great for producing an object from an array:
var value_keys = macPacketGroup.all().reduce(function(p, kv) {
if(!p[kv.value])
p[kv.value] = [];
p[kv.value].push(kv.key);
return p;
}, {});
Great:
{
"1": [
"b8:1d:ab:d1",
"dc:d9:16:3a",
"dc:d9:16:3b"
],
"2": [
"6c:17:79:03",
"6c:27:79:04",
"b8:1d:aa:d1",
"b8:1d:aa:d2",
"dc:da:16:3d"
],
But we wanted an array of key/value pairs, not an object!
var key_count_value_macs = Object.keys(value_keys)
.map(k => ({key: k, value: value_keys[k]}));
Great, that looks just like what a "real group" would produce:
[
{
"key": "1",
"value": [
"b8:1d:ab:d1",
"dc:d9:16:3a",
"dc:d9:16:3b"
]
},
{
"key": "2",
"value": [
"6c:17:79:03",
"6c:27:79:04",
"b8:1d:aa:d1",
"b8:1d:aa:d2",
"dc:da:16:3d"
]
},
...
Wrapping all that in a "fake group", which when asked to produce .all(), queries the original group and does the above transformations:
function value_keys_group(group) {
return {
all: function() {
var value_keys = group.all().reduce(function(p, kv) {
if(!p[kv.value])
p[kv.value] = [];
p[kv.value].push(kv.key);
return p;
}, {});
return Object.keys(value_keys)
.map(k => ({key: k, value: value_keys[k]}));
}
}
}
Now we can plot the pie chart! The only fancy thing here is that the value accessor should look at the length of the array for each value (instead of assuming the value is just a number):
packetPie
// ...
.group(value_keys_group(macPacketGroup))
.valueAccessor(kv => kv.value.length);
Demo fiddle.
However, clicking on slices won't work. I'll return to that in a minute - just want to hit "save" first!
Part 2: Filtering based on counts
As I remarked at the start, it's not possible to create a crossfilter dimension which will filter based on the count of connections. This is because crossfilter always needs to look at each row and determine, based only on the information in that row, whether it belongs in a group or filter.
If you add another chart at this point and try clicking on a slice, everything in the other charts will disappear. This is because the keys are now counts, and counts are invalid mac addresses, so we're telling it to filter to a key which doesn't exist.
However, we can obviously filter by mac address, and we also know the mac addresses for each count! So this isn't so bad. It just requires a filterHandler.
Although, hmmm, in producing the fake group, we seem to have forgotten value_keys. It's hidden away inside the function, and then let go.
It's a little ugly, but we can fix that:
function value_keys_group(group) {
var saved_value_keys;
return {
all: function() {
var value_keys = group.all().reduce(function(p, kv) {
if(!p[kv.value])
p[kv.value] = [];
p[kv.value].push(kv.key);
return p;
}, {});
saved_value_keys = value_keys;
return Object.keys(value_keys)
.map(k => ({key: k, value: value_keys[k]}));
},
value_keys: function() {
return saved_value_keys;
}
}
}
Now, every time .all() is called (every time the pie chart is drawn), the fake group will stash away the value_keys object. Not a great practice (.value_keys() would return undefined if you called it before .all()), but safe based on the way dc.js works.
With that out of the way, the filterHandler for the pie chart is relatively simple:
packetPie.filterHandler(function(dimension, filters) {
if(filters.length === 0)
dimension.filter(null);
else {
var value_keys = packetPie.group().value_keys();
var all_macs = filters.reduce(
(p, v) => p.concat(value_keys[v]), []);
dimension.filterFunction(k => all_macs.indexOf(k) !== -1);
}
return filters;
});
The interesting line here is another call to Array.reduce. This function is also useful for producing an array from another array, and here we use it just to concatenate all of the values (mac addresses) from all of the selected slices (connection counts).
Now we have a working filter. It doesn't make too much sense to combine it with the box plot from the last question, but the new fiddle demonstrates that filtering based on number of connections does work.
Part 3: what about zeroes?
As commonly comes up, crossfilter considers a bin with value zero to still exist, so we need to "remove the empty bins". However, in this case, we've added a non-standard method to the first fake group, in order to allow filtering. (We could have just used a global there, but globals are messy.)
So, we need to "pass through" the value_keys method:
function remove_empty_bins_pt(source_group) {
return {
all:function () {
return source_group.all().filter(function(d) {
return d.key !== '0';
});
},
value_keys: function() {
return source_group.value_keys();
}
};
}
packetPie
.group(remove_empty_bins_pt(value_keys_group(macPacketGroup)))
Another oddity here is we are filtering out the key zero, and that's a string here!
Demo fiddle!
Alternately, here's a better solution! Do the bin filtering before passing to value_keys_group, and then we can use the ordinary remove_empty_bins!
function remove_empty_bins(source_group) {
return {
all:function () {
return source_group.all().filter(function(d) {
//return Math.abs(d.value) > 0.00001; // if using floating-point numbers
return d.value !== 0; // if integers only
});
}
};
}
packetPie
.group(value_keys_group(remove_empty_bins(macPacketGroup)))
Yet another demo fiddle!!
I'm trying to use map-reduce to understand when this can be helpful.
So I have a collection named "actions" with 100k docs like this:
{
"profile_id":1111,
"action_id":2222
}
Now I'm trying to do map-reduce examples. I'm trying to get a list of "all users and total actions each one has". Is this possible? My code:
db.fbooklikes.mapReduce(
function(){
emit(this.profile_id, this.action_id);
},
function(keyProfile, valueAction){
return Array.sum(valueAction);
},
{
out:"example"
}
)
.. This is not working. The result is:
"counts" : {
"input" : 100000,
"emit" : 100000,
"reduce" : 1146,
"output" : 13
},
"ok" : 1,
"_o" : {
"result" : "map_reduce_example",
"timeMillis" : 2539,
"counts" : {
"input" : 100000,
"emit" : 100000,
"reduce" : 1146,
"output" : 13
},
"ok" : 1
},
What I'm trying to do is something possible with map-reduce?
Well yes you can use it, but the more refined response is that there are likely better tools for doing what you want.
MapReduce is handy for some tasks, but usually best suited when something else does not apply. The inclusion of mapReduce in MongoDB pre-dates the introduction of the aggregation framework, which is generally what you should be using when you can:
db.fbooklikes.aggregate([
{ "$group": {
"_id": "$profile_id",
"count": { "$sum": 1 }
}}
])
Which will simply return the counts for the all documents in the collection grouped by each value of "profile_id".
MapReduce requires JavaScript evaluation and therefore runs much slower than the native code functions implemented by the aggregation framework. Sometimes you have to use it, but in simple cases it is best not to, and there are some quirks that you need to understand:
db.fbooklikes.mapReduce(
function(){
emit(this.profile_id, 1);
},
function(key,values){
return Array.sum(values);
},
{
out: { "inline": 1 }
}
)
The biggest thing people miss with mapReduce is the fact that the reducer is almost never called just once per emitted key. In fact it will process output in "chunks", thus "reducing" down part of that output and placing it back to be "reduced" again against other output until there is only a single value for that key.
For this reason it is important to emit the same type of data from the reduce function as is sent from the "map" function. It's a sticky point that can lead to weird results when you don't understand that part of the function. It is in fact the underlying way that mapReduce can deal with large values of results for a single key value and reduce them.
But generally speaking, you should be using the aggregation framework where possible, and where a problem requires some special calculations that would not be possible there, or otherwise has some complex document traversal where you need to inspect with JavaScript, then that is where you use mapReduce.
You don't want to sum the action ids, you want to count them. So you want something like the following
var map = function () {
emit(this.profile_id, { action_ids : [this.action_id], count : 1 });
}
var reduce = function(profile_id, values) {
var value = { action_ids: [], count: 0 };
for (var i = 0; i < values.length; i++) {
value.count += values[i].count;
value.action_ids.push.apply(value.action_ids, values[i].action_ids);
}
return value;
}
db.fbooklikes.mapReduce(map, reduce, { out:"example" });
This will give you an array of action ids and a count for each profile id. The count could be obtained by accessing the length of the action_ids array, but I thought I would keep it separate to make the example clearer.
I'd like to come up with a good way to have a "suggested" order for how to sort an array in javascript.
So say my first array looks something like this:
['bob','david','steve','darrel','jim']
Now all I care about, is that the sorted results starts out in this order:
['jim','steve','david']
After that, I Want the remaining values to be presented in their original order.
So I would expect the result to be:
['jim','steve','david','bob','darrel']
I have an API that I am communicating with, and I want to present the results important to me in the list at the top. After that, I'd prefer they are just returned in their original order.
If this can be easily accomplished with a javascript framework like jQuery, I'd like to hear about that too. Thanks!
Edit for clarity:
I'd like to assume that the values provided in the array that I want to sort are not guaranteed.
So in the original example, if the provided was:
['bob','steve','darrel','jim']
And I wanted to sort it by:
['jim','steve','david']
Since 'david' isn't in the provided array, I'd like the result to exclude it.
Edit2 for more clarity:
A practical example of what I'm trying to accomplish:
The API will return something looking like:
['Load Average','Memory Usage','Disk Space']
I'd like to present the user with the most important results first, but each of these fields may not always be returned. So I'd like the most important (as determined by the user in some other code), to be displayed first if they are available.
Something like this should work:
var presetOrder = ['jim','steve','david']; // needn't be hardcoded
function sortSpecial(arr) {
var result = [],
i, j;
for (i = 0; i < presetOrder.length; i++)
while (-1 != (j = $.inArray(presetOrder[i], arr)))
result.push(arr.splice(j, 1)[0]);
return result.concat(arr);
}
var sorted = sortSpecial( ['bob','david','steve','darrel','jim'] );
I've allowed for the "special" values appearing more than once in the array being processed, and assumed that duplicates should be kept as long as they're shuffled up to the front in the order defined in presetOrder.
Note: I've used jQuery's $.inArray() rather than Array.indexOf() only because that latter isn't supported by IE until IE9 and you've tagged your question with "jQuery". You could of course use .indexOf() if you don't care about old IE, or if you use a shim.
var important_results = {
// object keys are the important results, values is their order
jim: 1,
steve: 2,
david: 3
};
// results is the orig array from the api
results.sort(function(a,b) {
// If compareFunction(a, b) is less than 0, sort a to a lower index than b.
// See https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Array/sort
var important_a = important_results[a],
important_b = important_results[b],
ret;
if (important_a && !important_b) {ret = -1}
else if (important_b && !important_a) {ret = 1}
else if (important_a && important_b) {ret = important_a - important_b}
else {ret = 0}; // keep original order if neither a or b is important
return(ret);
}
)
Use a sorting function that treats the previously known important results specially--sorts them to the head of the results if present in results.
items in important_results don't have to be in the results
Here's a simple test page:
<html>
<head>
<script language="javascript">
function test()
{
var items = ['bob', 'david', 'steve', 'darrel', 'jim'];
items.sort(function(a,b)
{
var map = {'jim':-3,'steve':-2,'david':-1};
return map[a] - map[b];
});
alert(items.join(','));
}
</script>
</head>
<body>
<button onclick="javascript:test()">Click Me</button>
</body>
</html>
It works in most browsers because javascript typically uses what is called a stable sort algorithm, the defining feature of which is that it preserves the original order of equivalent items. However, I know there have been exceptions. You guarantee stability by using the array index of each remaining item as it's a1/b1 value.
http://tinysort.sjeiti.com/
I think this might help. The $('#yrDiv').tsort({place:'start'}); will add your important list in the start.
You can also sort using this function the way you like.
Live demo ( jsfiddle seems to be down)
http://jsbin.com/eteniz/edit#javascript,html
var priorities=['jim','steve','david'];
var liveData=['bob','david','steve','darrel','jim'];
var output=[],temp=[];
for ( i=0; i<liveData.length; i++){
if( $.inArray( liveData[i], priorities) ==-1){
output.push( liveData[i]);
}else{
temp.push( liveData[i]);
}
}
var temp2=$.grep( priorities, function(name,i){
return $.inArray( name, temp) >-1;
});
output=$.merge( temp2, output);
there can be another way of sorting on order base, also values can be objects to work with
const inputs = ["bob", "david", "steve", "darrel", "jim"].map((val) => ({
val,
}));
const order = ["jim", "steve", "david"];
const vMap = new Map(inputs.map((v) => [v.val, v]));
const sorted = [];
order.forEach((o) => {
if (vMap.has(o)) {
sorted.push(vMap.get(o));
vMap.delete(o);
}
});
const result = sorted.concat(Array.from(vMap.values()));
const plainResult = result.map(({ val }) => val);
Have you considered using Underscore.js? It contains several utilities for manipulating lists like this.
In your case, you could:
Filter the results you want using filter() and store them in a collection.
var priorities = _.filter(['bob','david','steve','darrel','jim'],
function(pName){
if (pName == 'jim' || pName == 'steve' || pName == 'david') return true;
});
Get a copy of the other results using without()
var leftovers = _.without(['bob','david','steve','darrel','jim'], 'jim', 'steve', 'david');
Union the arrays from the previous steps using union()
var finalList = _.union(priorities, leftovers);