html: when should I use the "crossorigin" attribute in a "preconnection"?

All the answers so far seem to be partially incorrect or incomplete (the topic is complex, things have a confusing name and are not well documented!), So here is my understanding:

To reuse the connection created by , things depend on what type of content you want to obtain, from where, if the request will send browser credentials (which the browser can explicitly or implicitly set):

There is no need for preconnect not at all first; The browser keeps the connection open after loading the page for quite some time.

to be checked: What if the request of the same origin has crossorigin attribute: is it used or ignored?

  • if the actual request (in HTML or via JS) has crossorigin attribute explicitly established (crossOrigin in JS – the case is important), the pre-connection must also have it, with the same value (maybe except in cases where it makes no sense and crossorigin it's ignored, it's still not completely clear to me)
  • otherwise, if requested if for

Nofollow or Dofollow link attribute New directory

Hi everyone,

As a title, I have been in the directory industry for many years, but it is still a gray area with respect to the above, yes, I am trying to build a quality local business directory and I have configured all outgoing links to & # 39 ; NoFollow & # 39; But now I wonder if I should set & # 39; Dofollow & # 39 ;, this can be changed to order for individual business profile pages if a website URL is added.


Product attribute filter code

How does product attribute filtering work? It seems to return values ​​through ajax when some URL like this is called "test.html? Color = 5459 & size = 5447", but where is this ajax called? And what controller method are you calling? I need to analyze your code and I can't seem to locate them.

Creating a product attribute that has a conditional drop-down menu

How do I add the product attributes drop-down menu that sets its value based on another drop-down value selection? As if choosing the country, the following drop-down menu shows all its states.

magento2 – Magento 2 Get the value of the custom attribute in Magento 2 Rest API V1 / orders / items

You have to do your Custom Attribute attribute as extension attribute for MagentoSalesApiDataOrderItemInterface

create extension_attributes.xml in its modules app/code/{Vendorname}/{ModuleName}/etc.


I I guess your field as varchar is why I have to add type as a string variable (type="string")

magento2 – Magento 2: Payment order summary shows custom product attribute

I am trying to display a custom product attribute in the payment order summary section.
I have achieved this by canceling vendor/magento/module-checkout/view/frontend/web/js/view/summary/item/details.js
Y vendor/magento/module-checkout/view/frontend/web/template/summary/item/details.html files in my custom module and also created plugin
for getconfig() Method to store custom attributes in totalsData.

My question is:

1) If I cancel vendor/magento/module-checkout/view/frontend/web/js/view/summary/item/details.js file using
app/code/Test/Checkoutsummary/view/frontend/requirejs-config.js The file and then the custom attribute are shown in the order summary, but the product thumbnail is not displayed and in the console the error js is shown below:

enter the description of the image here

app / code / Test / Checkoutsummary / view / frontend / requirejs-config.js

var config = {
    map: {
        "*": {
            'Magento_Checkout/js/view/summary/item/details': 'Test_Checkoutsummary/js/view/summary/item/details'

2) If I cancel vendor/magento/module-checkout/view/frontend/web/js/view/summary/item/details.js file using
app/code/Test/Checkoutsummary/view/frontend/layout/checkout_index_index.xml design file instead of requirejs-config.js the file shows the custom attribute and all sections look good and
There was also no error found in the console.

app / code / Test / Checkoutsummary / view / frontend / layout / checkout_index_index.xml


So I don't understand why it shows a console error when it cancels summary/item/details.js archive
using requirejs-config.js archive.
Has anyone faced this kind of problem? Any help should be appreciated. Thank you

python: initializing an attribute in a secondary class that is used in the primary class

I am using a third-party Python library (wxPython), which has a class with errors in one of its modules.
The problematic code section looks like this:

def OnText(self, event):
    value = self.GetValue()
    if value != self.__oldvalue:
        pass  # Here some more code follows ...
    self.__oldvalue = value

The problem is the if statement, because on the first call to this method self.__oldvalue It has not yet been initialized. So, for an alternative solution until the library developers have solved this error, I thought I could fix it with a small solution. I just wanted to derive a secondary class from that defective class and initialize self.__oldvalue in this constructor:

class MyIntCtrl(wx.lib.intctrl.IntCtrl):
    def __init__(self, *args, **kw):
        self.__oldvalue = None
        super().__init__(*args, **kw)

However, now when I use this new class MyIntCtrl instead of the original IntCtrl class, I get exactly the same error as before:

Traceback (most recent call last):
  File "/usr/local/lib/python3.6/dist-packages/wx/lib/", line 509, in OnText
    if value != self.__oldvalue:
AttributeError: 'MyIntCtrl' object has no attribute '_IntCtrl__oldvalue'

Now I wonder: what am I doing wrong? How else can I solve this problem in a children's class?

(wocommerce) How to display the variation attribute and the price on the store page? (Only the first variation)

In wocommerce I have configured products with variations.
At this time, the store page shows only the minimum and maximum price like this: € 1 – € 10.
How can you show the variation attribute and the price of the variation of the minimum price (like this: 2 kg € 10)?

magento2 – Magento 2 Try loading the value of the nonexistent EAV attribute with CategoryInterface after migration

after 1.x 2.3
I receive the following error in my System.log file.

[2020-02-06 13:29:01] main.WARNING: Attempt to load value of nonexistent EAV attribute '903' 
                        for entity type 'MagentoCatalogApiDataProductInterface'. [] []

I looked for the value 903 with queries:

SELECT * FROM catalog_category_entity_datetime WHERE attribute_id = 903;
SELECT * FROM catalog_category_entity_decimal WHERE attribute_id = 903;
SELECT * FROM catalog_category_entity_int WHERE attribute_id = 903;
SELECT * FROM catalog_category_entity_text WHERE attribute_id = 903;
SELECT * FROM catalog_category_entity_varchar WHERE attribute_id = 903;

there are no 903 values ​​in the previous tables

With the query below I get a result:

SELECT * FROM `catalog_eav_attribute` WHERE `attribute_id` = 903 ORDER BY `attribute_id` ASC 

you can help?

Edit a value of an attribute of a table in MySQL from Netbeans using Java

I have this project, basically it is an inventory system of a candy store, the problem is that it gives me an error of the type java.lang.NullPointerException but it does not tell me in which line, when taking the attribute 'quantity' of the inventory table and add or subtract depending on the operation, the inventory table has an id (PK), quantity, product_id (FK) and a state_id (FK) and when displaying it in a jFrame I make a join by calling the attribute description of the product table through the id of the same, that is not a problem, the problem is to save the new amount, I already tried several sentences and it gives me the same error, can you help me?
I enclose the code that I try to use to add inventory, I suppose it will be similar to subtract it

    private void btningresoActionPerformed(java.awt.event.ActionEvent evt) {                                           

        Connection con = null;
        PreparedStatement ps;
        ResultSet rs;
        PreparedStatement ps1;
        ResultSet rs1;
        PreparedStatement ps2;
        ResultSet rs2;
        try {

            //Sentencia ps guarda id, cantidad y categoria
            //Sentencia ps1 guarda nombre llamando el nombre con el idproducto
            ps = con.prepareStatement("SELECT a.id_producto,b.nombre,a.cantidad,a.id_categoria FROM tblinventario a, tblproducto b WHERE a.id_producto = ?");
            ps1 = con.prepareStatement("SELECT a.id_producto,b.nombre,a.cantidad,a.id_categoria FROM tblinventario a, tblproducto b WHERE b.idproducto = ?");
            ps.setString(1, txtbuscar.getText());
            ps1.setString(1, txtbuscar.getText());

            rs = ps.executeQuery();
            rs1 = ps1.executeQuery();
            String cantidad = txtcantidad.getText();
            int total = 0;
            int viejoStock = 0;
            int nuevoStock =0;
            nuevoStock = Integer.parseInt(cantidad);

            if ( {
                viejoStock = Integer.parseInt(rs.getString(3));
                total = viejoStock + nuevoStock;
                ps2 = con.prepareStatement("UPDATE tblinventario SET cantidad=? WHERE id_producto= ?");
                ps2.setString(1, txtcantidad.getText());
                ps2.setString(2, txtbuscar.getText());
                int res = ps2.executeUpdate();
                if (res > 0) {
                    JOptionPane.showMessageDialog(null, "Cantidad 
/*  */