Using map\reduce with nested elements in javascript - javascript

I have a search form that allows the user to add as many search terms as they like. When the user enters all of the search terms and their search values and clicks search, a text box will be updated with the search terms. I've got this working with a for loop, but I'm trying to improve my dev skills and am looking for a way to do this with map\filter instead.
Here's the code I'm trying to replace:
var searchTerms = $("#search-form").find(".mdc-layout-grid__inner");
var searchString = "";
for(var i = 0; i < searchTerms.length - 1; i ++)
{
var select = $(searchTerms[i]).find(".select2-selection")[0];
var selectText = $(select).select2('data')[0].text + ":";
var textBox = $(searchTerms[i]).find(".mdc-text-field__input")[0];
searchString = searchString += selectText.replace(/\./g,"").replace(/ /g,"") + textBox.value;
if(i < searchTerms.length - 1)
{
searchString = searchString += " ";
}
}
$("#er-search-input").val(searchString);
Here's a codepen of the current solution.
i'm trying the below, but I get the feeling I'm miles away:
const ret = searchTerms.map((u,i) => [
$($(u[i]).find(".select2-selection")[0]).select2('data')[0].text + ":",
$(u[i]).find(".mdc-text-field__input")[0].value,
]);
My question is, is it possible to do this with map?

Firstly you're repeatedly creating a jQuery object, accessing it by index to get an Element object only to then create another jQuery object from that. Instead of doing this, you can use eq() to get a specific element in a jQuery object by its index.
However if you use map() to loop through the jQuery object then you can avoid that entirely by using this to reference the current element in the iteration. From there you can access the required elements. The use of map() also builds the array for you, so all you need to do is join() the results together to build the required string output.
Finally, note that you can combine the regex expressions in the replace() call by using the | operator, and also \s is more robust than using a whitespace character. Try this:
var $searchTerms = $("#search-form").find(".mdc-layout-grid__inner");
var searchString = $searchTerms.map(function() {
var $searchTerm = $(this);
var selectText = $searchTerm.find('.select2-selection').select2('data')[0].text + ':';
var $textBox = $searchTerm.find('.mdc-text-field__input:first');
return selectText.replace(/\.|\s/g, "") + $textBox.val();
}).get().join(' ');
$("#er-search-input").val(searchString);

Related

JS Array Find and Replace?

I have a regular expression happening that searching for all the capitals in a document. It gathers them and puts them into an array no problem.
The issue I am having is I want to replace the items in that array to include a span around each item that was captured in the array and then display the updated result. I've tried a variety of things.
I am at a complete loss. Any help is appreciated. Here was my last attempt
var allCaps = new RegExp(/(?:[A-Z]{2,30})/g);
var capsArray = [];
var capsFound;
while (capsFound = allCaps.exec(searchInput)) {
capsArray.push(capsFound[0]);
}
//for(var x = 0; x < capsArray.length; x++){
//var test = ;
capsArray.splice(0, '<span style="color:green">'+ capsArray +'</span>');
//}
}
You can't convert an entire array's elements like that using splice - you can use .map instead:
capsArray = capsArray.map(c => '<span style="color:green">' + c + '</span>');
Do you need the results in an array? If not, you can wrap all caps in a str using a modified regex:
str.replace(/([A-Z])/g, '<span>$1</span>')
example:
'A--B--C' becomes '<span>A</span>---<span>B</span>---<span>C</span>'
if the array is needed for whatever reason:
str.split(/[^A-Z]+/g).map(x => `<span>${x}</span>`)
example:
'A--B--C' becomes ['<span>A</span>', '<span>B</span>', '<span>C</span>']
Thanks to everyone for the help.
Heres my final solution for anyone else that gets lost along the way
var allCaps = new RegExp(/(?:[A-Z]{2,30})/g);
var capsArray = [];
var capsFound;
while (capsFound = allCaps.exec(searchInput)) {
capsArray.push(capsFound[0]);
}
if(capsArray.length > 0){
resultsLog.innerHTML += "<br><span class='warning'>So many capitals</span><br>";
searchInput = document.getElementById('findAllErrors').innerHTML;
searchInput = searchInput.replace(/([A-Z]{3,30})/g, '<span style="background-color:green">$1</span>');
document.getElementById('findAllErrors').innerHTML = searchInput;
}
else {
resultsLog.innerHTML += "";
}

how to loop though div and get each value

I am trying to figure out how to get each value within my div. I am using
var cart = $('.basic-cart-cart-node-title.cell').text();
It is giving the results of OI-01OP-01OS-10-5SOR-04OR-05
I need to view them one by one: OI-01, OP-01, OS-10-5S, OR-04 OR-05.
So that I can match them against another field.
If you care to help me further, I have another div on the page:
var ParNum = $('.assess-title').text();
I would like to compare the values returned from the var cart and see if that value is in the ParNum. If it is there, I would like to apply a class.
Any help would be greatly appreciated.
Thanks!
You can store the values in an array using .map() method:
var values = $('.basic-cart-cart-node-title.cell').map(function() {
return $.trim( $(this).text() );
}).get();
For checking existence of the ParNum value in the array:
var does_exist = values.indexOf(ParNum) > -1;
Try this to iterate over elements:
var text = '';
$('.basic-cart-cart-node-title.cell').each(function (i, div) {
text += ' ' + $(div).text();
});
or this to get an array of matching div elements:
var divs = $('.basic-cart-cart-node-title.cell').toArray();
for (var i = 0; i < divs.length; i++) {
// $(div).text();
}
Reason for this is that $('.basic-cart-cart-node-title.cell') returns all div's at once, and you need to loop through the result. More specifically, $(selector) returns a so-called "wrapped set". It can be used to access each matching element (as I've shown above) or it can be used to apply any other jQuery function to the whole set at once. More info here.
var text = "";
$('.basic-cart-cart-node-title.cell').each(function(){
text += $(this).text() + ", ";
});
// remove the last ", " from string
text = text.substr(0, text.length -2);
var cart = [];
$('.basic-cart-cart-node-title.cell').each(function {
cart.push($(this).text());
}
This performs the matching and class adding you mentioned in the question.
var ParNum = $('.assess-title').text();
$('basic-cart-cart-node-title.cell').each(function () {
if ($(this).text() == ParNum) {
$(this).addClass("someclass");
}
}
You should try using
var cart ='';
$('.basic-cart-cart-node-title'.find('.cell').each(function()
{
cart = cart + $(this).val();
});
Hope it works for you.
var cart = $('.basic-cart-cart-node-title.cell').text().match(/.{5}/g);
This will give you an array with items 5 chars long. Regexes arent very fast, but a loop might be slower
Or easier to read, and in a string with commas:
var cart = $('.basic-cart-cart-node-title.cell').text(); // get text
cart = cart.match(/.{1,5}/g); // split into 5 char long pieces
cart = cart.join(",",); join on comma

function to change argument to another sign

I dynamically create this list element and information a user has typed in shows up in it when a button is clicked 'info' is text and shuld show as it is but 'grade' is a number that i want to convert to another sign with the function changeNumber() but I am new to javascript and cant figure out how to make this function, can anyone give a suggestion or point me in the right direction?
var list = $("#filmlista");
var list_array = new Array();
function updateFilmList()
{
document.getElementById("name").value = '';
document.getElementById("star").value = 0;
var listan = list_array[0][0];
var grade = list_array[0][1];
var element = '<li class="lista">' + list + '<span class="grade">'+ changeNumber(grade) +'</span></li>';
list.append(element);
}
should I use innerHTML? not shure I understand how it works? and how do I use the replace method if I have to replace many different numbers to the amount of signs the number is?
for example if the number is 5 it should show up as: *****, if number is 3 show up as: *** and so on
Here's some code that should do the trick:
Add this function into your script.
function changeNumber(number) {
var finalProduct = "";
for (var i = 0; i < number; i++) {
finalProduct += "*";
}
return finalProduct;
}
Replace the updateFilmsList with this code.
document.getElementById("name").value = '';
document.getElementById("star").value = 0;
var listan = list_array[0][0];
var grade = changeNumber(list_array[0][1]);
var element = '<li class="lista">' + list + '<span class="grade">'+ grade +'</span></li>';
list.append(element);
It looks like you're trying to do something like PHP's str_repeat. In that case, take a look at str_repeat from PHPJS
There are options other than a loop:
function charString(n, c) {
n = n? ++n : 0;
return new Array(n).join(c);
}
charString(3, '*'); // ***
You can use innerHTML to set the text content of an element provided none of the text might be mistaken for markup. Otherwise, set the textContent (W3C compliant) or innerText (IE proprietary but widely implemented) property as appropriate.

Looping over array and comparing to regex

So, I'll admit to being a bit of a JS noob, but as far as I can tell, this should be working and it is not.
Background:
I have a form with 3 list boxes. The list boxes are named app1, db1, and db2. I'm using javascript to allow the user to add additional list boxes, increasing the name tag for each additional select box.
When I add additional app named boxes, the value increments properly for each additional field. If I try to add addtional db named selects, it fails to recognize the 2nd tag on the first loop through the array. This causes me to end up with 2 elements named db2. On each subsequent tag, it is recognized properly and is properly incremented.
Here is the HTML for the db1 tag:
<select name="db1">
*options*
</select>
And db2:
<select name="db2">
*options*
</select>
The tags are identical. Here is the function that I am using to figure out the next number in the sequence (note: tag is either app or db, tags is an array of all select tag names in the DOM, if I inspect tags, it gives me ['app1', 'db1', 'db2', '']):
function return_select_name(tag, tags) {
matches = new Array();
var re = new RegExp(tag + "\\d+", "g");
for (var i = 0; i < tags.length; i++) {
var found = re.exec(tags[i]);
if (found != null) {
matches.push(found[0]);
}
}
matches = matches.sort();
index = parseInt(/\d+/.exec(matches.last())) + 1;
index = tag + index;
return index;
}
If I add an app tag, it will return 'app2'. If I search for a db tag, it will return 'db2' on the first time through, db3 on the 2nd, etc, etc.
So basically, I'm sure I'm doing something wrong here.
I'd handle it by keeping a counter for db and a counter for app to use to generate the names.
var appCounter = 1;//set this manually or initialize to 0 and
var dbCounter = 2;//use your create function to add your elements on pageload
Then, when you go to create your next tag, just increment your counter and use that as the suffix for your name:
var newAppElement = document.createElement('select');
newAppElement.name = 'app' + (++appCounter);
..
// --OR for the db element--
var newDbElement = document.createElement('select');
newDbElement.name = 'db' + (++dbCounter );
..
The problem you are getting is that regex objects are stateful. You can fix your program by putting the regex creation inside the loop.
function return_select_name(tag, tags) {
matches = new Array();
// <-- regex was here
for (var i = 0; i < tags.length; i++) {
var re = new RegExp(tag + "\\d+", "g"); //<--- now is here
var found = re.exec(tags[i]);
if (found != null) {
matches.push(found[0]);
}
}
matches = matches.sort();
index = parseInt(/\d+/.exec(matches[matches.length-1])) + 1; //<--- I dont think matches.last is portable, btw
index = tag + index;
return index;
}
In any case, if I were to do this myself, I would probably prefer to avoid the cmplicated text matching and just store the next tag indices in a variable or hash map.
Another suggestion: if you put parenthesis in your regex:
// /tag(\d+)/
var re = new RegExp(tag + "(\\d+)", "g");
Then you can use found[1] to get your number directly, without the extra step afterwards.
I know this has already been answered, but I put this together as a proof of concept.
http://jsfiddle.net/zero21xxx/LzyTf/
It's an object so you could probably reuse it in different scenarios. Obviously there are ways it could be improved, but I thought it was cool so I thought I would share.
The console.debug only works in Chrome and maybe FF.

Javascript / DOM, parsing Key/Value string

I send a string from a server to the Firefox Browser in the format below:
"KEY:a1 VAL:123.45"
And this string can contain many such records.
Here is the code I have written:
var e;
var reply = request.responseText;
var txt = "", tab, key = "", val = "";
var x = reply.getElementsByTagName("KEY:");
for(i = 0; i < x.length; i++)
{
txt = x[i].childNodes[0].nodeValue; // "KEY:%c%c VAL:%.2F"
tab = txt.split(":");
key = "table_" + tab[1].substring(0,1);
val = tab[2];
e = document.getElementById(key);
e.innerHTML = val;
e.style.display = "block";
}
val displays "KEY:a1 VAL:123.45" instead of the expected "123.45" (and of course the key variable is also wrong, not matching a table cell, just picking the first one in the table).
I don't even know how to display the key and val values (document.write() and alert() do nothing and I don't see how to trace this code in Firefox).
Any idea, tip, correction, or code example is welcome but please don't recommend using any library, I want to do it with little code.
EDIT: from the two comments, I understand that there are two distinct ways to proceed: either using DOM objects and HTML tags, or using 'strings'. I would prefer to keep using the format above, so please guide me to a 'string' solution. Thanks!
You can use a simple regular expression to extract the information from the string:
var value = "KEY:a1 VAL:123.45"​,
pattern = /KEY:(\S+) VAL:(.+)$/g;
var result = pattern.exec(value);
// result[1] == 'a1'
// result[2] == '123.45'
In your case, you'd use request.responseText instead of value.

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