更改struts2的标头值属性<s:select>

Question

I am using Struts2 framework. I want to change the header value of a <s:select> using javascript.

Here is my code:

<s:select label="Select Table" name="tableCheck" id="tableCheck" list="%{queryTableDisplay}" cssStyle="WIDTH:152px" headerKey="-1" headerValue="-- Select --"/>

Answer 1

Just get your select element by id and change values in javascript.

// changes option value attribute
document.getElementById("tableCheck").options[0].value = "new_header_key";
// changes option inner HTML
document.getElementById("tableCheck").options[0].innerHTML = "new_header_value";

Answer 2

Even I have tried doing it and I have come to know that we cannot set header value of <s:select> using javascript. On page-load,ie on DOM structure creation of page, <s:select> expands and headerkey and header value form option-name parts of select tag.You can view it in page source. However, there is way by which you can set select list to some default value. To auto select a default value for a drop down box, just declared a “value” attribute in the tag, and set the default value accordingly.

JAVA FILE

public class SelectAction extends ActionSupport{

private List<String> searchEngine;
    private String yourSearchEngine;
//set default value
    public String getDefaultSearchEngine() {

        return "yahoo.com";
    }
  public SelectAction(){    
        searchEngine = new ArrayList<String>();
        searchEngine.add("google.com");
        searchEngine.add("bing.com");
        searchEngine.add("yahoo.com");
        searchEngine.add("baidu.com");
    }
    //...
}

JSP

<s:select label="What's your favor search engine" 
        headerKey="-1" headerValue="Select Search Engines"
        list="searchEngine" 
        name="yourSearchEngine" 
        value="defaultSearchEngine" />