Svelte, on:click event inside each block triggers on page load - events

The problem is that in svelte on:click triggers on page load for some reason. Can anybody explain to me why it's happening and how to prevent it so it only triggers when you actually check the box. This only happens if on:click is inside each block.
<script>
function handleClick(number) {
alert(number)
}
let numbers = [1,2,3,4,5,6]
</script>
{#each numbers as number}
<input type=checkbox on:click={handleClick(number)}>
{/each}
You can look at it here

The value of on:click should be a function. You're invoking a function — it's no different from doing something like this...
<p>{a} + {b} = {sum(a, b)}</p>
...which, as you'd expect, prints the result of calling the sum function.
Instead, do this:
<input type=checkbox on:click={() => handleClick(number)}>

Related

How to select elements with same ID but in different shadow DOMs

So I'm working at a co. as a summer intern and have been tasked with writing tests for their application in cypress.
The application extensively uses shadow DOMs and nested shadow DOMs even. I used the includeShadowDom property true to traverse more easily. But I am facing an issue.
I need to type in 2 input boxes having the same ID and same class but they are in separate shadows. Is there a way I can distinguish between them i.e First occurrence of element with id= and nth occurrence of element with id=?
I can't share any code because it goes against company policy
Assuming you have added includeShadowDom: true in your cypress config file then you can use the eq method to get the respective elements.
E.g. eq(0) for first occurrence of the element, eq(1) for the second and so on.
So your code should look like this:
cy.get('input').eq(0).type('some text')
First possible solution is to select every input with class = something and loop over each.
let words = ['First input', 'second input']
cy.get(`input[class="something"]) // this returns x number of Inputs
.each( ($el, index) => {
cy.get($el)
.type(words[index])
})
Second possible solution is to target the parent element incasing the single input.
cy.get('table') //I don't know what is incasing your inputs but lets assume its a table
.within( () => {
cy.get(`input[class="something"`] //trying to get this to return 1 element
.type('words')
})
Without seeing your HTML markup I can't offer up a more exact solutions. Hope this helps. Look up parent() and parentsUntil() cypress commands if you try the second option.
With inputs there's usually some text that allows the user to distinguish them.
Try targeting the input label or placeholder text, finding the input with "Traversal" commands.
<div>
<label>User name</label>
<input type="text" placeholder="Enter user name" />
<div>
Some basic approaches:
cy.contains('label', 'User name')
.next() // move to next element in the DOM
.type('something')
cy.contains('div', 'User name') // go to common parent of label and input
.find('input') // gives just the input inside parent
.type('something')
cy.get('input[placeholder="Enter user name"]') // use unique placeholder attribute
.type('something')
With shadow DOM be aware you can configure it in the test header
it('searches inside all shadow dom roots', {includeShadowDom: true}, () => {
...
})

How to populate select fast and only once

I have over 3200 rows in a Google Sheet. I need a dropdown with each value on a web app.
I have this in Apps Script:
function doGet(e) {
var htmlOutput = HtmlService.createTemplateFromFile('CensusWebApp2');
var streets = getStreets();
var businessNames = getbusinessNames();
htmlOutput.message = '';
htmlOutput.streets = streets;
htmlOutput.businessNames = businessNames;
return htmlOutput.evaluate();
}
function getbusinessNames(){
var ss= SpreadsheetApp.getActiveSpreadsheet();
var StreetDataSheet = ss.getSheetByName("businessNames");
var getLastRow = StreetDataSheet.getLastRow();
var return_array = [];
return_array= StreetDataSheet.getRange(2,1,getLastRow-1,1).getValues();
return return_array;
}
This is the HTML code
<select type="select" name="IntestazioneTari" id="IntestazioneTari" class="form-control" >r>
<option value="" ></option>
<? for(var i = 0; i < businessNames.length; i++) { ?>
<option value="<?= businessNames[i] ?>" ><?= businessNames[i] ?></option>
<? } ?>
</select><be>
I'm creating an app similar to surveys forms, but this dropdown will be the same for every entry.
Is there a way to load this only once and not every time the form is submitted and got again for a new survey entry? (from the same operator/device)
I believe your goal as follows.
You want to use the value of businessNames retrieved from Google Spreadsheet at HTML side.
The value of businessNames is not changed. So you want to load the value only one time.
In this case, how about declaring the value in the tag of <script> as a global? When this point is reflected to your script it becomes as follows.
Modified script:
In this case, your HTML side is modified.
<select type="select" name="IntestazioneTari" id="IntestazioneTari" class="form-control" >r>
<option value="" ></option>
<? for(var i = 0; i < businessNames.length; i++) { ?>
<option value="<?= businessNames[i] ?>" ><?= businessNames[i] ?></option>
<? } ?>
</select>
<input type="button" value="ok" onclick="test()">
<script>
const value = JSON.parse(<?= JSON.stringify(businessNames) ?>); // Here, the value of "businessNames" is retrieved.
function test() {
console.log(value);
}
</script>
In this modification, when the HTML is loaded, the value of businessNames is added to the HTML by evaluate() method. At that time, businessNames is given to HTML and Javascript. By this, const value = JSON.parse(<?= JSON.stringify(businessNames) ?>); has the value of businessNames. In order to confirm this value, when you click a sample button of <input type="button" value="ok" onclick="test()">, you can see the value at the console. By this, you can use the value of businessNames at the Javascript side after HTML is loaded.
Reference:
HTML Service: Templated HTML
As the values from the spreadsheet won't change, I created a really long text row with all the options and pasted them directly in the HTML.
I made the same with the other information. Load time decreased enormously.
This is the code I use to generate the values:
return_array= "<option>" + businessNamesSheet.getRange(2,1,getLastRow-1,1).getValues().join("</option><option>")+"</option>";
We are talking about performance, and there are 3 things you need to do when doing so:
Make measurements
Make measurements again
And make some more measurements
A change in the code could have a negative impact for a reason that you didn't expect (it's hard to keep every single little detail in mind). When making a Google Apps Script web app, you have 3 reported times:
The timings in your browser. How much did it really take to load the entire page
The running time on Google Apps Script execution log.
Small timing inside your application using console.time (reference), console.timeLog (reference) and console.timeEnd (reference) (collectively called console timers).
Note that the first 2 may change without you changing a thing, probably because of the inner working in Google.
So let's start doing what I said: measuring. I'd measure:
The entire doGet function
The getStreets()
The getbusinessNames()
The template.evaluate()
How much time it takes to load the page (browser)
This will give me a rough idea on what takes most of the time. Knowing that, you can try the following ideas.
Note that I don't have your code so I can't tell how it will effect your times, so your mileage may vary. Also note that most ideas could be implemented simultaneously, this doesn't mean it's a good idea and can even slow what a single idea could have achieved.
Idea 1: Copy the generated options into the template
If you don't need to load the options from somewhere (like I suppose you are doing), you could generate the template once, copy the generated options and paste it to the HTML. This will obviously avoid the problem of having the request the list of options and evaluating them every time, but you lose flexibility.
Idea 2: Having the options in code instead of somewhere else
If the options won't change or you will be changing them, you could add them into your code:
const BUSINESS_NAMES = `
business 1
hello world
another one
and another one
`
function getbusinessNames() {
return BUSINESS_NAMES
.split('\n')
.filter(v => !!v) // remove empty string
}
It's similar to idea 1 but it's easier to change the values when needed, specially when using the V8 support for multi line strings.
Idea 3: Use a Google Apps Script cache
If what's taking time is querying the options, you could use CacheService (see reference). This would allow you to only query the options every X seconds (up to 6 hours) instead of every time.
function doGet(e) {
// [...]
const cache = CacheService.getScriptCache()
let businessNames = cache.get('businessNames')
if (businessNames == null) {
businessNames = getbusinessNames()
cache.put('businessNames', businessNames, 6*60*60)
}
// use businessNames
// [...]
}
In this case I've only done it with businessName but it can also be use in streets.
having a 6 hour cache means that it could take up to 6 hours for a change in the list to propagate. If you add the options manually you could add a function to force the reloading it:
function forcecacheRealod() {
cache.put('streets', getStreets(), 6*60*60)
cache.put('businessNames', getbusinessNames(), 6*60*60)
}
Idea 4: Improve how you load the data
Is very common for new Google Apps Script users to iterate the rows one by one getting the value. It's way more efficient to get the proper range with all the rows and columns and call getValues (reference).
Idea 5: do a fetch instead of submitting the form
If what is happening is that it takes time to load after sending the data, it might be a good idea to use google.script.run (reference) instead of making a form and submitting it, since it could prevent reloading the entire page again.
Idea 6: SPA web app
The result of doubling down on the last idea. Same benefits and you could load the necessary data in the background while the user lands on the home page.
Idea 7: Load the options dynamically
Use google.script.run (reference) to load the options once the page has already been loaded. May actually be slower but you can give faster feedback to the user.
Idea 8: Save the options in localStorage
Requires idea #7. Save the dynamically loaded options into localStorage(see reference) so the user only needs to wait once. You may need to load them once in a while to make sure they are up-to-date.
References
Console timer (MDN)
CacheService (Google Apps Script reference)
Range.getValues() (Google Apps Script reference)
Class google.script.run (Client-side API) (Google Apps Script reference)
Window.localStorage (MDN)

Angular2 Is it possible to have several events one after the other

I have a component y which uses directive :
<div makeDroppable (dropped)="getDroppedList($event)">
<ul>
<li *ngFor="let task of toAddList" >{{task.id}}</li>
</ul>
</div>
at the end of directives MakeDroppable , an event is emit
let data = JSON.parse(ev.dataTransfer.getData('text'));
this.dropped.emit(data);
this event is treated by (dropped)="getDroppedList($event)" (in div) and thus calls getDroppedList of my component.
in this getDroppedList méthod, another event is emit
this.toAddList = <Array<Task>>event;
console.log('emity event');
this.toto.emit(this.toAddList);
this new event toto is used in another component x where html is
<tr *ngFor="let task of tasks" (toto)="removeDroppedList($event)">
removeDroppedList is a method defined in x
removeDroppedList(event){
console.log('this second event')
when i execute code, the second event does not seem to be treated because the 'this second event' is never displayed in console.
i put a breakpoint at console.log('this second event'), but
it never stops
Missing " after tasks in your template.
Assuming the missing " isn't relevant, is there a disconnect with the todo event? What I mean is, are there more than one todo object being created? How does component Y have reference to component X's todo event?
Seems like you need a service so both components have reference to the same event object as component X would need to have that as an output and component Y would get it's reference from the service so it can emit a value.

Submitting form without fixed number of inputs

In my JSP file I have form with flexible number of inputs - user has a possibility to add or delete inputs of a form(I did it using Javascript). Therefore form hasn't got a fixed number of inputs. This is required. Now I want to create controller taking these parameters but... I can't specify how many of inputs there will be. They're all Strings. Is there any way to pass these inputs into a controller? I'm using Spring and JSP for the views.
It is no simplest variant, but anyway:
$('#yourInputForm').submit(function (event) {
event.preventDefault();
var arr = []
$('#yourInputForm').find('input').each(function () {
arr.push($(this).val());
});
});
Pay attention, I didn't check if val() is empty.
Inside this function you can send you arr with ajax to your controller.

Extract part of HTML document in jQuery

I want to make an AJAX call to an HTML-returning page, extract part of the HTML (using jQuery selectors), and then use that part in my jQuery-based JavaScript.
The AJAX retrieval is pretty simple. This gives me the entire HTML document in the "data" parameter of the callback function.
What I don't understand is how to handle that data in a useful way. I'd like to wrap it in a new jQuery object and then use a selector (via find() I believe) to get just the part I want. Once I have that I'll be passing it off to another JavaScript object for insertion into my document. (This delegation is why I'm not using jQuery.load() in the first place).
The get() examples I see all seem to be variations on this:
$('.result').html(data);
...which, if I understand it correctly, inserts the entire returned document into the selected element. Not only is that suspicious (doesn't this insert the <head> etc?) but it's too coarse for what I want.
Suggestions on alternate ways to do this are most welcome.
You can use your standard selector syntax, and pass in the data as the context for the selector. The second parameter, data in this case, is our context.
$.post("getstuff.php", function(data){
var mainDiv = $("#mainDiv", data); // finds <div id='mainDiv'>...</div>
}, "html");
This is equivalent to doing:
$(data).find("#mainDiv");
Depending on how you're planning on using this, $.load() may be a better route to take, as it allows both a URL and a selector to filter the resulting data, which is passed directly into the element the method was called on:
$("#mylocaldiv").load("getstuff.php #mainDiv");
This would load the contents of <div id='mainDiv'>...</div> in getstuff.php into our local page element <div id='mylocaldiv'>...</div>.
You could create a div and then put the HTML in that, like this…
var div = $("<div>").html(data);
...and then filter the data like this…
var content = $("#content", div.get(0));
…and then use that.
This may look dangerous as you're creating an element and putting arbitrary HTML into it, but it's not: anything dangerous (like a script tag) will only be executed when it's inserted into the document. Here, we insert the data into an element, but that element is never put into the document; only if we insert content into the document would anything be inserted, and even then, only anything in content would be inserted.
You can use load on a new element, and pass that to a function:
function handle(element){
$(element).appendTo('body');
}
$(function(){
var div = $('<div/>');
div.load('/help a', function(){handle(div);});
});
Example: http://jsbin.com/ubeyu/2
You may want to look at the dataFilter() parameter of the $.ajax method. It lets you do operations on the results before they are passed out.
jQuery.ajax
You can do the thing this way
$.get(
url,
{
data : data
},
function (response) {
var page_content = $('.page-content',response).get(0);
console.log(page_content);
}
)
Here in the console.log you will see the inner HTML of the expected/desired portion from the response. Then you can use it as your wish

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