javascript 如何单击“选择选项”，然后使用 casperjs 评估加载的内容

How to click a "select option" and then evaluate loaded content with casperjs

提问by 2083

I'm trying to crawl the sizes for this product:

我正在尝试抓取此产品的尺寸：

Link to product

产品链接

The problem: The sizes are loaded after the color of the product is selected.

问题：选择产品颜色后加载尺寸。

In the product page's source code, I can see that the dropdown has a onchange-method: It clicks the form #postColor onchange.

在产品页面的源代码中，我可以看到下拉菜单有一个 onchange 方法：它点击表单 #postColor onchange。

The select dropdown:

选择下拉列表：

<select name="color" id="color" class="cposelect" onchange="document.getElementById('postColor').click();" style="width:150px;margin-right: 20px; float: left;">
    <option selected="selected" onfocus="if (this.storeCurrentControl != null) storeCurrentControl(event, this);" value="0">Select colour</option>
    <option onfocus="if (this.storeCurrentControl != null) storeCurrentControl(event, this);" value="-8027">Light Camel</option>
    <option onfocus="if (this.storeCurrentControl != null) storeCurrentControl(event, this);" value="-9999">black</option>
</select>

The #postColor form, which is clicked onchange:

#postColor 表单，点击后更改：

<input type="submit" name="postColor" value="" onclick="location.href=('./?model=10344-4180&amp;color='+document.forms[0].color.value+'&amp;size='+document.forms[0].size.value+'&amp;addbread=OUTLET&amp;addbread2=DRIZIA&amp;currentimage='+document.getElementById('currentimage').value+'&amp;selectedmi=a1_INDEX_14&amp;prev=10850-4314&amp;next=10413-4183'); return false;" id="postColor" class="cpobutton " style="display: none;">

This is my code so far and it's not working:

到目前为止，这是我的代码，但它不起作用：

casper.start('http://shop.baumundpferdgarten.com/showmodel/?model=10344-4180&addbread=OUTLET&addbread2=DRIZIA&color=0&currentimage=1&selectedmi=a1_INDEX_14', function() {
    this.test.assertExists('select[name="color"] option:nth-child(2)');
    this.click('select[name="color"] option:nth-child(2)');
    this.waitForSelector('select[name="size"] option:nth-child(2)', function() {
        this.test.pass('selector is !');
        var sizes = this.evaluate(function() {
            console.log("======== evaluating ========");
            // var sizes = document.querySelectorAll('#size option');
            return document.querySelectorAll('#size option');
        });
        for (var i = sizes.length - 1; i >= 0; i--) {
            console.log(sizes[i].innerText);
        }
    });
});

I suspect that problem is that a totally new page is loaded when a color is clicked (the sizes are not dynamically appended).

我怀疑这个问题是点击颜色时加载了一个全新的页面（尺寸不是动态附加的）。

How would you solve this problem?

你会如何解决这个问题？

回答by wmarbut

This is how I do it

这就是我的做法

this.evaluate(function() {
    $('#select_element_selector').val('value').change();
});

The change()is very important

将change()是非常重要的

I'm assuming that you have jQuery on the page

我假设您在页面上有 jQuery

回答by Valery Lyatsevich

Got same issue here. My solution is:

这里有同样的问题。我的解决办法是：

casper.then(function(){
    this.evaluate(function() {
        document.querySelector('select.select-category').selectedIndex = 2; //it is obvious
    });
    this.capture('screenshot.png');
});

回答by tfmontague

The recommended jQuery solution doesn't actually work for me.

推荐的 jQuery 解决方案实际上对我不起作用。

casper.evaluate(function() {
    $('#select_element_selector').val('value').change();
});

While, the capture()command shows the select option as selected visually, it doesn't actually trigger the event. Try using this with the waitForText()command for example; the program will timeout.

虽然该capture()命令在视觉上将选择选项显示为选中，但它实际上并未触发事件。waitForText()例如，尝试将其与命令一起使用；程序将超时。

casper
  .start('http://factfinder.census.gov/faces/tableservices/jsf/pages/productview.xhtml?pid=DEC_00_SF1_DP1&prodType=table')
  .waitForText('Add/Remove Geographies', function () {
    casper.click('#addRemoveGeo_btn');
  })
  .waitForText('Select a geographic type:', function () {
    casper.evaluate(function () {
      $('#summaryLevel').val('050').change();
    });
  })
  .waitForText('Select a state:', function () {
    casper.capture('test.png');
  })
  .run();

What did work for me, was the code provided below (thanks @ArtjomB). How to fill a select element which is not embedded in a form with CasperJS?

对我有用的是下面提供的代码（感谢@ArtjomB）。 如何使用CasperJS填充未嵌入表单的选择元素？

casper.selectOptionByValue = function(selector, valueToMatch){
    this.evaluate(function(selector, valueToMatch){
        var select = document.querySelector(selector),
            found = false;
        Array.prototype.forEach.call(select.children, function(opt, i){
            if (!found && opt.value.indexOf(valueToMatch) !== -1) {
                select.selectedIndex = i;
                found = true;
            }
        });
        // dispatch change event in case there is some kind of validation
        var evt = document.createEvent("UIEvents"); // or "HTMLEvents"
        evt.initUIEvent("change", true, true);
        select.dispatchEvent(evt);
    }, selector, valueToMatch);
};

casper.selectOptionByValue('#summaryLevel', '050');

Although, I think CasperJS should provide native support to select options from a drop-down when they aren't apart of a form (http://docs.casperjs.org/en/latest/modules/index.html). Selenium offers the selectand addSelectioncommands (https://seleniumhq.github.io/selenium/docs/api/javascript/index.html). I've also filed a pending issue ticket on the CasperJS GitHub page to implement this natively (https://github.com/n1k0/casperjs/issues/1390).

虽然，我认为 CasperJS 应该提供原生支持，以便在它们不属于表单（http://docs.casperjs.org/en/latest/modules/index.html）时从下拉列表中选择选项。Selenium 提供select和addSelection命令（https://seleniumhq.github.io/selenium/docs/api/javascript/index.html）。我还在 CasperJS GitHub 页面上提交了一个待处理的问题单，以在本地实现它（https://github.com/n1k0/casperjs/issues/1390）。

回答by Ravishankar

this is simple code to enter credit card details in casper js

这是在 casper js 中输入信用卡详细信息的简单代码

casper.evaluate(function(CC,security_code) {

casper.evaluate（函数（CC，security_code）{

      document.querySelector('input#receipt_creditcard_number').value = CC;
      document.querySelector('select#receipt_creditcard_month').selectedIndex = 10;
      document.querySelector('select#receipt_creditcard_year').selectedIndex = 10;
      document.querySelector('input#receipt_creditcard_verification_value').value = security_code;
      document.querySelector('input#receipt_save_creditcard_in_profile').click();
  }, '4242424242424242','123');

回答by tejesh95

vanilla javascript solution (triggering onchange method):

vanilla javascript 解决方案（触发 onchange 方法）：

casper.evaluate(function() {
    var select_element = document.getElementById('select_element_selector');
    select_element.value = 'value';
    select_element.onchange();
});

回答by George Worthington

tejesh95's solution worked for me with a few minor changes, #1 I couldn't get findElementById to work so switched it to 'document.querySelector('#selectorId)' . I also had to change 'onchange' to 'onclick'. Here's the code within the casperjs test harness:

tejesh95 的解决方案对我有用，做了一些小改动，#1 我无法让 findElementById 工作，所以将它切换到 'document.querySelector('#selectorId)' 。我还必须将“onchange”更改为“onclick”。这是 casperjs 测试工具中的代码：

casper.then(function() {
  this.evaluate(function() {
  var select_element = document.querySelector('#selectorId')
  select_element.value = 'stringValue'
  select_element.onclick
})

})

})

Follow on note: Your mileage may vary on the above, I found inconsistent results elsewhere, the text value would update, but the underlying control wouldn't fire. Frustrating!

请注意：您的里程可能与上述有所不同，我在其他地方发现不一致的结果，文本值会更新，但底层控件不会触发。令人沮丧！

回答by Ruskin

A slightly hacky way to do this withoutusing jQuery utilising built-in casper methods is:

在不使用 jQuery 的情况下使用内置的 casper 方法来做到这一点的一种稍微有点hacky 的方法是：

// Assumes the select box is on the first item at index 0
chooseSelectOption = (friendlyName : string, selectLocator : string, optionIndex : number) => {
    casper.test.assertExists(selectLocator, "then select index " + optionIndex + " in the " + friendlyName + " select box");
    casper.click(selectLocator);
    this.goDown(selectLocator, optionIndex);
};

// recursive funtion to go down various levels
private goDown = (locator: string, depth : number, currentLevel : number = 0) => {
    if (currentLevel >= depth) { return; }
    casper.sendKeys(locator, casper.page.event.key.Down, { keepFocus: true });
    this.goDown(locator, depth, currentLevel + 1);
};

This is in TypeScript but you can edit for vanilla JS if you need to. You need to use a recursive function because a normal for loop gets into difficulties with capser's queuing system.

这是在 TypeScript 中，但如果需要，您可以为 vanilla JS 进行编辑。您需要使用递归函数，因为普通的 for 循环在使用 capser 的排队系统时会遇到困难。

回答by imjared

Tricky, but looking at the URL, I think Casper can handle this nicely.

棘手，但查看 URL，我认为 Casper 可以很好地处理这个问题。

Let me know if you need help with the code for this but it will take a bit longer so to give you a bit of pseudo-code,

如果您需要有关代码的帮助，请告诉我，但需要更长的时间，因此给您一些伪代码，

• create an empty object of colors and color IDs { color: colorId }
• as you're already kind of doing, find the select menu with [name='color'] and loop through those options. push anything that doesn't have a value of 0 to your object
• write a new function that will go to the url http://shop.baumundpferdgarten.com/showmodel/?model=10344-4180&color=-9999&size=0&addbread=OUTLET&addbread2=DRIZIA&currentimage=1&selectedmi=a1_INDEX_14&prev=10850-4314&next=10413-4183and substitute the color ID where color=-9999.

• 创建颜色和颜色 ID 的空对象 { color: colorId }
• 正如您已经在做的那样，找到带有 [name='color'] 的选择菜单并循环浏览这些选项。将任何值不为 0 的内容推送到您的对象
• 编写一个新函数，该函数将转到 urlhttp://shop.baumundpferdgarten.com/showmodel/?model=10344-4180&color=-9999&size=0&addbread=OUTLET&addbread2=DRIZIA&currentimage=1&selectedmi=a1_INDEX_14&prev=10850-4314&next=10413-4183并替换颜色 ID where color=-9999。

example:

'http://shop.baumundpferdgarten.com/showmodel/?model=10344-4180&color=' + object.colorId + '&size=0&addbread=OUTLET&addbread2=DRIZIA&currentimage=1&selectedmi=a1_INDEX_14&prev=10850-4314&next=10413-4183'

例子：

'http://shop.baumundpferdgarten.com/showmodel/?model=10344-4180&color=' + object.colorId + '&size=0&addbread=OUTLET&addbread2=DRIZIA&currentimage=1&selectedmi=a1_INDEX_14&prev=10850-4314&next=10413-4183'

• Either add the sizes to the existing colors object or make a new one, or console.log them. The world is yours!

• 将大小添加到现有颜色对象或创建一个新对象，或使用 console.log 记录它们。世界是你的！

回答by Fabio

I don't know if you found a solution to your problem, but here is how I would solve it:

我不知道您是否找到了解决问题的方法，但这是我的解决方法：

casper.click('#color');
casper.then(function() {
casper.waitFor(function check() {
  return this.evaluate(function() {
    return document.querySelector('select.select-category').selectedIndex === 2; 
  });
}, function then() {
     /* do the rest that you would want to do!*/
   });

}