covert large array of objects into smaller array objects using javascript - javascript

I have an list of values like this from a sql database.
UserName Email ComputerName DateIssued
jjsmith jjsmith#example.com JTComputer 9/14/2013
ltjoseph ltjoseph#example.com LTComputer1 10/21/2013
KTsmith KevinTem#example.com KTComputer1 01/25/2012
ltjoseph ltjoseph#example.com LTComputer2 01/11/2013
KTsmith KevinTem#example.com KTComputer2 01/25/2012
I transform my list into an array of objects.
var user_array = [
{"username":"jjsmith", "email":"jjsmith#example.com", "computerName":"JTComputer", "dateissued":"10/21/2013"}
{"username":"ltjoseph", "email":"ltjoseph#example.com", "computerName":"LTComputer1", "dateissued":"10/21/2013"}
{"username":"KTsmith", "email":"KevinTem#example.com", "computerName":"KTComputer1", "dateissued":"01/25/2012"}
{"username":"ltjoseph", "email":"ltjoseph#example.com", "computerName":"LTComputer2", "dateissued":"01/11/2013"}
{"username":"KTsmith", "email":"KevinTem#example.com", "computerName":"KTComputer2", "dateissued":"01/25/2012"}]
A function has been created by someone else that sends emails to users, it only accepts two parameters which are strings.
So I don't want to send more than 1 email per user. So I am trying to figure out how to combine the items together so that my an example set of strings look like this.
var str1 = "ltjoseph#example.com";
var str2 = "ltjoseph, LTComputer1-10/21/2013, LTComputer2-01/11/2013";
and then fire the other user function to send emails for each of the items in the list.
function sendEmails(str1, str2);
If anyone has any ideas how i can do this. Please advise..

var by_user = {};
for (var i = 0; i < user_array.length; i++) {
if (by_user[user_array[i].username]) {
// Found user, add another computer
by_user[user_array[i].username].str2 += ', ' + user_array[i].computerName + '-' + user_array[i].dateissued;
} else {
// First entry for user, create initial object
by_user[user_array[i].username] = {
str1: user_array[i].email,
str2: user_array[i].username + ', ' + user_array[i].computerName + '-' + user_array[i].dateissued
};
}
}
Now you have the by_user object, which has a single sub-object for each user, whose str1 and str2 properties are the variables you want.
by_user['ltjoseph'].str1 => ltjoseph#example.com
by_user['ltjoseph'].str2 => ltjoseph, LTComputer1-10/21/2013, LTComputer2-01/11/2013

something like this:
var str1=array[0].email
var str2=array[0].username+", "+array[0].computerName+array[0].dateissued
or use a loop and iterate through the array

I strongly recommend bringing in a library like lodash for this sort of thing and using uniq (sample here: http://jsfiddle.net/MwYtU/):
var uniqs = lodash(user_array).pluck('email').uniq().value();
If you're doing javascript and aren't acquainted with lodash or underscore, go do that because it'll save you a lot of time. Using tried and true code is a good idea. Added bonus: if you want to see how the pros are doing something like uniq you can just look at the source code.

Related

How to properly read array from a data table on Code.Org AppLab?

I created a table called "morning" in AppLab, and one column stores data as an array (or list as it calls it). I'm able to properly add data to this array, but my problem is reading the data back (as I want to display it as a label/normal text on another page) If the numbers 1234 and 5678 are the values in the array, when I try to do
console.log(records[i].id + ': ' + records[i].buses);
The second value (buses) is the name of the column I'm trying to read back, which will result in "," rather than "1234,5678" and I'm not really sure what to do. This is the code I have so far, any help would be greatly appreciated!
readRecords("morning", {}, function(records) {
for (var i =0; i < records.length; i++) {
console.log((records[i]).id + ': ' + records[i].(buses[i]));
}
});
var ts1Buses = ["1234"];
var ts1Change;
onEvent("enterTS1", "click", function(event) {
appendItem(ts1Buses, getText("textTS1"));
updateRecord("morning", {id:1, buses:ts1Buses}, function(record, success) {
setText("textTS1", "");
});
});
The console.log statement in your longer block of code doesn't look quite right. try console.log(records[i].id + ': ' + records[i].buses); instead. if that doesn't work, please post a link to your project so that others can try to find a fix by remixing and editing it.
App Lab's data tables do not support arrays. They will have to be converted into comma-separated strings before creating or updating and converted to an array after reading.
To convert an array to a string, simply use the toString() method:
var array = ["a", "b", "c"];
console.log(array.toString()) // "a,b,c"
To convert a string into an array, use the split() method:
var string = "a,b,c";
console.log(string.split(","); // ["a", "b", "c"]

Custom query parameters format serializer and extractor [JS]

I have a JSON object of the type
[
{
at: "own",
op: "in_between",
va: ["str", "jan"]
},
{
a: 'alas',
op: 'cont',
va: [10, 20]
},
.
.
.
]
I want to pass this as a GET query parameter. Now I could just stringify it and pass it as something like this
?q={"0":{"at":"own","op":"in_between","va":["str","jan"]},"1":{"at":"alas","op":"cont","va":[10,20]}}
However I would prefer to serialize it in a different format. Something like
q[]=at:"own"|op:"in_between"|va:["str","jan"]&q[]=at:"alas"|op:"cont"|va:[10,20]
(I saw a this kind of format being used in Amazon's search filters. Any other format suggestions are welcome. My main goal is to shorten the URL)
So i was able to serialize it by just concatenating to a string
let q = "";
data.forEach(function(i) {
q = q.concat(`q[]=at:"${i.at}"|op:"${i.op}"|va:[${i.val}]&`);
});
return q.slice(0,-1);
Similarly I have an extractor
let qArray = q.split('&');
let qParse = [];
qArray.forEach(function(i) {
i = JSON.parse('{' + i.substring(4).split('|').join(',') + '}');
q.push(i);
});
However this only works well for q[1] where q[1]['va'] has an integer array. It needs to also work for q[0] with the string values
Also is there any better way of serializing and extracting it in these kinds of forms?
Thanks in advance!
As said previously in the comments, I was wondering if CSV wouldn't work for what you want. It's kind of easy to parse. Would this work (assuming filters is your array) ? :
let params = "?q=;at,op,va;";
filters.forEach(function(fil) {
params += fil.at + "," + fil.op + "," + JSON.stringify(fil.va) + ";";
})
If you want to store queries to make percentage, you'd just have to remove first three characters. I'm also supposing that all your dictionnaries follow the same structure. Hope this works for you

How to access JSON-object with multiple values per key?

At the moment I am stuck with a problem that just seems stupid, but I don't know the answer to it.
I am trying to access this JSON-object:
var custom_fields =
{
"28246": 5123,5124,5125
}
I would like to get each value from that key. I would know how to access it if it was a nested-object, but it isn't sadly (it is coming from an API, which I can't change the JSON-response from sadly)
What I tried already is the following:
for (var key in custom_fields) {
if (custom_fields.hasOwnProperty(key)) {
console.log(key + " -> " + custom_fields[key]);
}
}
The problem here is that the result will be like this:
1 -> 5
2 -> 1
3 -> 2
4 -> 3
5 -> ,
6 -> 5
...etc...
Any suggestions are welcome, I am trying to access it in javascript/Jquery.
Thanks for helping in advance!
I assume that the data is in this format (note the string literals):
var custom_fields = {
"28246": "5123,5124,5125"
}
If that is the case, you can use String.split.
In your case, it would be something like this:
const values = custom_fields['28246'].split(',');
The values of they key 28246 are now stored in the new variable values as an array:
['5123','5124','5125']
If you want to parse all values to integers, I suggest using Array.map:
const valuesAsInt = custom_fields['28246'].split(',').map(value => parseInt(value);
Which will lead to this:
[5123, 5124, 5125]
Disclaimer: When using newer ECMAScript features such as Array.map, be sure to either use a browser which supports this our include a polyfill.
You can access it by using split function which will convert it into an array and then get the values from that array as below code.
var data = {
"28246": '5123,5124,5125'
}
var arr = data['28246'].split(',');
$.each(arr, function( index, value ) {
console.log(value);
});
You can split by ',' and transform each element to integer by using array.map and '+' operator:
var custom_fields =
{
"28246": "5123,5124,5125"
}
custom_fields["28246"] = custom_fields["28246"].split(',').map(el => +el);
console.log(custom_fields);
console.log(custom_fields["28246"][0], custom_fields["28246"][1], custom_fields["28246"][2]);

resolving a javascript and database table logic situation

When I query a database table, I get back values "yes" or "no" for records that represent whether an item is present or not (the item is the column name). I want to create a string that represents the products that are available by name (rather than what I am doing now "kitchen table =" + kitchenTable;
I am thinking this can be solved (poorly) by a series of if statements setting variables to either the product name or to "" and then include all variables in the string
var kt;
if (kitchenTable == yes) kt = "kitchen table";
else kt = "";
if (kitchenCabinet == yes) kc = "kitchen cabinet";
else ka = "";
output = kt + ', ' + kc;
There are about 50 items that can be presented to the user, is there a more efficient way of accomplishing this task?? One option is to change how values are entered into the datbase table such that instead of yes, its the item name but this seems like a poorer way to resolve the issue
Of course you don't give all the details about how do you make query so that is an imaginary mockup of a function simulating query
var available = [];
var result = query("kitchen table");
result === "yes" && ( available.push("kitchen table") );
......
var output = available.join();
What you want is actually built into javascript itself.
I would say using an object literal will really simply your life in this situation by organizing your code and turning it into a more readable format.
I would also recommend turning your server data into true and false as this is a standardized way to communicated a Boolean and allows for the method below to work as it does:
// From server response
var results = {
kitchenCabinet: true,
kitchenTable: true
}
// Use this for your storage of all related items
var kitchenProps = {
kitchenCabinet: 'kitchen cabinet',
kitchenTable: 'kitchen table'
}
// Reuse this function for each time your need a new category (masterBathroomProps...)
function getItemDataIfExists(results, hashTable){
'use strict';
var output = 'Your total is: ';
for (var item in results) {
if (!results.hasOwnProperty(item)) return;
if (results[item]) output += 'A '+hashTable[item]+' ';
}
return output;
}
getItemDataIfExists(results, kitchenProps);
Explanation:
You loop through a result set of an object containing keys names and true false values. In the loop, if the keyname's value is true, then use that keyname to access the properties (in this case a string of your choice. The "key" here is that the key names in each object must line up.
Here is a live demo:
http://codepen.io/nicholasabrams/pen/JXXbYz?editors=0010

Is there a better way to make multiple JavaScript replace calls than doing them one by one?

I'm constructing a string in Javascript which will contain HTML.
Right now, I'm doing something like this:
var filter = "";
filter = util.getTemplate( "tmp_filter", temps );
filter = filter.replace( 'id="tmp_filter"','');
if (dyn.table.i18n) {
filter = filter.replace(util.regex.re_text, dyn.filter.clear_tx);
} else {
filter = filter.replace('data-i18n="[title]tmp_text"', 'title="'+dyn.filter.clear_tx+'" ');
filter = filter.replace('data-i18n="tmp_text">','>'+dyn.filter.clear_tx);
}
filter = filter.replace(util.regex.re_theme, dyn.filter.theme);
filter = filter.replace(util.regex.re_icon, dyn.filter.icon);
filter = filter.replace(util.regex.re_iconpos, dyn.filter.iconpos);
filter = filter.replace('class="ui-listview-filter ', 'class="ui-listview-filter '+ dyn.custom_classes[0]+' ');
Which pulls a template and replaces all placeholders with data specified in dyn.
While this works, it's an awful lot of replace calls. In SQL, I can nest replace calls like this
SELECT LEN(REPLACE(REPLACE(address, ' CA', ''), ' NY', '')) FROM Tbl
Question:
Is there a better way in Javascript to do multiple replace calls? I don't mind the length of the code, but I'm a little uneasy with filter = filter.replace. Just wondering if there is a better way to do?
Thanks!
You can chain all the replaces

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