使用if-else语句声明

Question

I use this code:

var x = require('casper').selectXPath;
...
casper.waitForSelector(x("//a[contains(@id,'cell_13_1')]"), function() {             
    this.test.assertExists(x("//a[contains(@id,'cell_13_1')]"), 'Clickable');
    this.click(x("//a[contains(@id,'cell_13_1')]"));
});

I am trying to use if-else with assertExists to click another element if the first is not there:

casper.waitForSelector(x("//a[contains(@id,'cell_13_1')]"), function() {          
    if(this.test.assertExists(x("//a[contains(@id,'cell_13_1')]")==="PASS"){
        this.click(x("//a[contains(@id,'cell_11_1')]"));} 
    else{
        this.click(x("//a[contains(@id,'cell_22_1')]"));
    }         
});

But that does not seem to work. How would one do it correctly?

Answer 1

That's exactly what casper.exists() is for. You can also explicitly pass or fail some things:

casper.waitForSelector(x("//a[contains(@id,'cell_13_1')]"), function() {          
    if(this.exists(x("//a[contains(@id,'cell_13_1')]")){
        this.test.pass("Clickable");
        this.click(x("//a[contains(@id,'cell_11_1')]"));
    } else {
        this.test.fail("Clickable");
        //this.click(x("//a[contains(@id,'cell_22_1')]"));
    }       
});

This code is equivalent to your first snippet. Comment the fail() call and uncomment the last click in order to get your "intended" behavior.

Btw, it doesn't make sense to fail some assertion and still continue with the script. You have to think about what exactly you want to test and what part of your script is supposed to be navigation to the component under test.