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How to concatenate and pass parameters values in html using jQuery

I'm using jQuery to get values from ajax rest call, I'm trying to concatenate these values into an 'a' tag in order to create a pagination section for my results (picture attached).
I'm sending the HTML (divHTMLPages) but the result is not well-formed and not working, I've tried with double quotes and single but still not well-formed. So, I wonder if this is a good approach to accomplish what I need to create the pagination. The 'a' tag is going to trigger the onclick event with four parameters (query for rest call, department, row limit and the start row for display)
if (_startRow == 0) {
console.log("First page");
var currentPage = 1;
// Set Next Page
var nextPage = 2;
var startRowNextPage = _startRow + _rowLimit + 1;
var query = $('#queryU').val();
// page Link
divHTMLPages = "<strong>1</strong> ";
divHTMLPages += "<a href='#' onclick='getRESTResults(" + query + "', '" + _reg + "', " + _rowLimit + ", " + _startRow + ")>" + nextPage + "</a> ";
console.log("Next page: " + nextPage);
}
Thanks in advance for any help on this.
Pagination

Rather than trying to type out how the function should be called in an HTML string, it would be much more elegant to attach an event listener to the element in question. For example, assuming the parent element you're inserting elements into is called parent, you could do something like this:
const a = document.createElement('a');
a.href = '#';
a.textContent = nextPage;
a.onclick = () => getRESTResults(query, _reg, _rowLimit, _startRow);
parent.appendChild(a);
Once an event listener is attached, like with the onclick above, make sure not to change the innerHTML of the container (like with innerHTML += <something>), because that will corrupt any existing listeners inside the container - instead, append elements explicitly with methods like createElement and appendChild, as shown above, or use insertAdjacentHTML (which does not re-parse the whole container's contents).

$(function()
{
var query=10;
var _reg="12";
var _rowLimit="test";
var _startRow="aa";
var nextPage="testhref";
//before divHTMLPages+=,must be define divHTMLPages value
var divHTMLPages = "<a href='#' onclick=getRESTResults('"+query + "','" + _reg + "','" + _rowLimit + "','" + _startRow + "')>" + nextPage + "</a>";
///or use es6 `` Template literals
var divHTMLPages1 = `` + nextPage + ``;
$("#test").append("<div>"+divHTMLPages+"</div>");
$("#test").append("<div>"+divHTMLPages1+"</div>");
});
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div id="test"></div>

Passing argument to on click event of dynamically generated element

I am trying to pass arguments to onclick event of dynamically generated element. I have already seen the existing stackoveflow questions but it didn't answer my specific need.In this existing question , they are trying to access data using $(this).text(); but I can't use this in my example.
Click event doesn't work on dynamically generated elements
In below code snippet, I am trying to pass program and macroVal to onclick event but it doesn't work.
onClickTest = function(text, type) {
if(text != ""){
// The HTML that will be returned
var program = this.buffer.program;
var out = "<span class=\"";
out += type + " consolas-text";
if (type === "macro" && program) {
var macroVal = text.substring(1, text.length-1);
out += " macro1 program='" + program + "' macroVal='" + macroVal + "'";
}
out += "\">";
out += text;
out += "</span>";
console.log("out " + out);
$("p").on("click" , "span.macro1" , function(e)
{
BqlUtil.myFunction(program, macroVal);
});
}else{
var out = text;
}
return out;
};
console.log of out give me this
<span class="macro consolas-text macro1 program='test1' macroVal='test2'">{TEST}</span>
I have tried both this.program and program but it doesn't work.

Obtain values of span element attributes, since you include them in html:
$("p").on("click" , "span.macro" , function(e)
{
BqlUtil.myFunction(this.getAttribute("program"),
this.getAttribute("macroVal"));
});
There are, however, several things wrong in your code.
you specify class attribute twice in html assigned to out,
single quotes you use are not correct (use ', not ’),
quotes of attribute values are messed up: consistently use either single or double quotes for attribute values
var out = "<span class='";
...
out += "' class='macro' program='" + program + "' macroVal='" + macroVal + ;
...
out += "'>";
depending on how many times you plan to call onClickTest, you may end up with multiple click event handlers for p span.macro.

js/jquery iterate through html elements to dynamically build a string

I'd like to build a string based on values defined in an html form only if they have been populated. I've successfully parsed the form fields and dropdown with a for loop ($.each()) but my ultimate goal is to dynamically build a string with the results. The string is being used to create a REST query, this is currently the only way to search based on our technologies. Does anyone have a recommended solution?
thx in advance
sample html element:
<input data-param=" prefix like '%" data-name="prefix" class="prefix uno" type="text" placeholder="pre">
working btn click event loop to capture filled in form fields:
var children = $(this).parent().children('.uno');
$.each(children, function(i, val){
if($(val).val() !== ''){
console.log($(val).data('name') + " "+ $(val).data('param') + " " + $(val).val());
}
});
goal:
var newString = field1.param + field1.val + '% ' + field2.param + field2.val + '% ';
translated:
var newString = prefix like '%01%' and name like '%tree%';

Thanks David Fregoli for the jquery serialize reference, that was close, but the solution ended up being to place the strings into a single array, change it toString(), and remove the ',' from the new string.
code:
var samp = [],
thisVal = $(this).parent().children('.uno');
$.each(thisVal, function(i, val){
if($(val).val() !== ''){
samp.push(
$(val).data('param'),
$(val).val(),
$(val).data('close')
);
}
});
itQuery.where = samp.toString().replace( /,/g , '');
result search string:
"number like '%08%' and field = 34"

Javascript add event listener in a foreach loop only last entry works

I have a function which goes through an Array and adds <h3> elements to a div. Then it adds an event listener (an onclick) to the current <h3> element, but only the last element which goes through the function is set by the onclick.
var runstr = [];
//txt comes from the content of a tab separated textfile spilt by '\n'
txt.forEach(function (lcb) { //lcb goes through each line of txt
lcb = lcb.split(" ", 30); //split the line by tab
//MainContent_Infralist is a div where the <h3> elements are listed and lcb[2] is the title
document.getElementById("MainContent_Infralist").innerHTML =
document.getElementById("MainContent_Infralist").innerHTML +
'<h3 class="Infraa" id="' + "Infralist_" + lcb[2] + '">' + lcb[2] + '</h3>';
//I put the id into an array to get the index of the marker later
runstr.push("Infralist_" + lcb[2]);
//I'm working with openlayers here i try to set the entry of
//the list.onlick to trigger a mousedown on a marker.
//And there is the problem: It works, but only for the last entry of my <h3> list...
document.getElementById("Infralist_" + lcb[2]).onclick = function () {
var theM = runstr.indexOf("Infralist_" + lcb[2]);
markers.markers[theM].events.triggerEvent('mousedown');
};
};

The problem is here:
document.getElementById("MainContent_Infralist").innerHTML =
document.getElementById("MainContent_Infralist").innerHTML +
'<h3 class="Infraa" id="' + "Infralist_" + lcb[2] + '">' + lcb[2] + '</h3>';
Every time you assign to innerHTML, you're basically deleting all stuff and adding it all over again. This causes all event listeners to break.
That's the reason why only last one works - it's the only one after assigning which there is no more innerHTML manipulation.
To fix this, create your elements using document.createElement() and append them using element.appendChild().
It could look like:
var header = document.createElement('h3');
header.id = 'Infralist_' + lcb[2];
header.className = 'Infraa';
header.textContent = lcb[2];
document.getElementById('MainContent_Infralist').appendChild(header);
header.onclick = function () {
// you function here
}

jQuery "undefined" prints when appending to html element

I'm making a jQuery MP3 player. The song structure is first generated (including the information about the song), and then the structure is appended to a div using jQuery like this:
function loadFromPlaylist(playlist) {
var songsStructure;
for (var i=0; i<playlist.length; i++) {
songsStructure +=
"<div id='song" + i + "'>" +
"<span class='mpPlaylistArtist'>" + playlist[i].artist + "</span>" +
"<span class='mpPlaylistSong'>" + playlist[i].song + "</span>" +
"<span class='mpPlaylistAlbum'>" + playlist[i].album + "</span>" +
"</div>";
}
$('#mpTracks').append(songsStructure);
}
This works perfectly except for one thing. When the items are displayed in the browser, a string ("undefined") is printed above the songs, like so:
<div id="mpTracks">
"undefined"
<div id="song0">...</div>
<div id="song1">...</div>
</div>
Googling this problem yielded alot of related problems but that didn't help me.
Does anyone know what the problem might be?

Initialize your variable to an empty string, before using it:
var songsStructure = '';
You did not set an initial value, so it is set to undefined. According to JS rules for concatination, this undefinedis then concatenated with the strings generated by the for loop leading to your result.

You have to initialize the songsStructure variable.
Write
function loadFromPlaylist(playlist) {
var songsStructure="";
and your problem will be solved.