修改現有的代碼，以接受多個參數

Question

請參閱下面的代碼以下問題描述：

// Populate a select list with pt codes. 
    this.populateCodeList = function (ptName_, listSelector_) { 

     if (!ptName_) { return self.displayError("Invalid pt name", "populatecodeList"); } 
     if (!listSelector_) { return self.displayError("Invalid list selector", "populatecodeList"); } 

     var pt = self.registry.pt[ptName_]; 

     if (!pt) { return self.displayError("Invalid PT: " + ptName_, "populateCodeList"); } 

     var html = ""; 

     $_.each(pt.codes, function (index_, code) { 

      if (!code || !code.id || !code.name) { return self.displayError("Invalid code at index " + index_, "populateCodeList"); } 

      html += "<option value='" + code.id + "'>" + code.name + "</option>"; 
     }); 

     $_(listSelector_).html(html); 
    }; 

問題描述：

我打電話就像在我的代碼如下上述功能：

app_.populateCodeList("First Attribute", self.selectors.add_attribute_dialog + " .attribute-name"); 

一切工作正常。然而，當我嘗試調用上述函數這樣具有第二屬性由逗號分隔 如下：

app_.populateCodeList("First Attribute,Second Attribute", self.selectors.add_attribute_dialog + " .attribute-name"); 

我得到以下錯誤Invalid PT:First Attribute,Second Attribute in populateCodeList這是這條線在上面的代碼if (!pt) { return self.displayError("Invalid PT: " + ptName_, "populateCodeList"); }

的結果

所以基本上我的代碼沒有被編程以處理由逗號但單可變分開的兩個參數，其在線所示

var pt = self.registry.pt[ptName_];

如何確保上面的行在需要時接受單參數和雙參數？

謝謝

Answer 1

您可以拆分分隔符或允許函數使用者傳遞數組。這裏是第一個建議的例子：

this.populateCodeList = function (ptName_, listSelector_) { 

    if (!ptName_) { return self.displayError("Invalid pt name", "populatecodeList"); } 
    if (!listSelector_) { return self.displayError("Invalid list selector", "populatecodeList"); } 

    var ptNames = ptName_.split(','); 
    // if empty, nothing was passed 
    if (!ptNames.length) { return self.displayError("No pt names supplied"); } 
    // iterate over all matches 
    var html = ""; 

    ptNames.forEach(function(ptName) { 
     var pt = self.registry.pt[ptName]; 
     if (!pt) { return self.displayError("Invalid PT: " + ptName, "populateCodeList"); } 

     $_.each(pt.codes, function (index_, code) { 

      if (!code || !code.id || !code.name) { return self.displayError("Invalid code at index " + index_, "populateCodeList"); } 

      html += "<option value='" + code.id + "'>" + code.name + "</option>"; 
     }); 

    }); 

    $_(listSelector_).html(html); 
}; 

Answer 2

這裏是你如何做它通過一個數組。

this.populateCodeList = function (ptNames_, listSelector_) { 

    if (!ptNames_) { return self.displayError("Invalid pt name", "populatecodeList"); } 
    if (!ptNames_.length) { return self.displayError("Invalid pt name", "populatecodeList"); } 

    if (!listSelector_) { return self.displayError("Invalid list selector", "populatecodeList"); } 

    var html = ""; 

    $_.each(ptNames_, function (ptName_) { 

     var pt = self.registry.pt[ptName_]; 

     if (!pt) { return self.displayError("Invalid PT: " + ptName_, "populateCodeList"); } 

     $_.each(pt.codes, function (index_, code) { 

      if (!code || !code.id || !code.name) { return self.displayError("Invalid code at index " + index_, "populateCodeList"); } 

      html += "<option value='" + code.id + "'>" + code.name + "</option>"; 
     }); 

    $_(listSelector_).html(html); 
}; 

，並調用它爲：

app_.populateCodeList(["First Attribute","Second Attribute"], self.selectors.add_attribute_dialog + " .attribute-name"); 

我也覺得更好的通過（我認爲）jQuery的元素融入到功能，而不是選擇，即：

this.populateCodeList = function (ptNames_, $list_) { 
    ... 
    $list_.html(html); 
} 

app_.populateCodeList(["First Attribute","Second Attribute"], 
         $_(self.selectors.add_attribute_dialog + " .attribute-name"));