創建動態下拉列表

Question

我在網上搜索相當長的一段時間以找到合適的解決方案，但迄今爲止我還沒有成功。

我試圖達到的目標：我創建了一個省下載的動態下拉框。只要用戶選擇其中一個動態創建的條目，區域的第二個動態下拉框應該僅根據所選省份顯示正確的條目。

爲此我已經建立了下面的代碼：

的search.php

//$i is running up to the max amount of provinces 
//for each province there shall be one option in the html select 
//the session array provinceresults contains key1, key2, province (english), province (other language) 
for($i=0; $i < $countProvinces; $i++) { 

    echo "<option value=".$_SESSION['provincesresults'][$i][0]." onClick=\"removeSelected(\".$i.\")\">".$_SESSION['provincesresults'][$i][1]."</option>"; 
} 

在search.php中我有應得到執行下面的JavaScript代碼的主體部分時，我選擇的一個每的onClick上述生成的選項：

<!--Javascript which is needed to call the dynamic_drop_down.php function per onClick event--> 
<script type=\"text/javascript\"> 
    function removeUnselected($key){ 
     document.getElementById(\"php_code\").innerHTML=\" 
     <?php 

      //Get all the values out of the district array out of pdo.vhd 
      $districtsSelected = removeUnselected(".$_SESSION['provincesresults'][$key][0]."); 
      } 
     ?>\"; 
    } 

所以我需要把第一個PHP部分的$ i計數器放到Javascript函數中。 之後，我需要在我的search.php

填充$ districtsSelected爲進一步使用我的search.php PHP函數removeUnselected（「。$ _ SESSION ['provincesresults'] [$ key] [0]。」）;看起來是這樣的，幷包含在search.php中：

<?php 

/** 
*This php file is used to retrieve the districts for a selected province. 
*This file is called by search.php. 
*As input, the function needs to be called with the ID of the selected province, it will return all related districts. 
*/ 

function removeUnselected($provinceKey) { 

    //Build the array which returns the needed districts 
    $districtsSelected = array(); 

    //Loop through all the districts that have been read out of the database by get_value_help.php 
    for($i = 0; $i < count($_SESSION['districtsresults']); $i++) { 

     //Check if the province id out of the table dbo.vhp matches with the id out of the table dbo.vhd 
     if(strcmp($provinceKey, $_SESSION['districtsresults'][$i][1]) == 0) { 

     //Give back the district names in english if the language settings are english 
     if($_SESSION['lng'] == "english") { 

      //Remove any districts that were not selected 
      $districtsSelected[] = $_SESSION['districtsresults'][$i][2]; 
     } 
      //Give back the district names in khmer if the language settings are khmer 
     elseif ($_SESSION['lng'] == "khmer") { 

      //Remove any districts that were not selected 
      $districtsSelected[] = $_SESSION['districtsresults'][$i][3]; 
     } 
     } 
    } 

    //Return the result 
    return($districtsSelected); 
} 
?> 

我如何能在工作方式構建這個任何建議高度讚賞！

謝謝和問候，

codac

編輯： 我使用下面的JavaScript： http://www.mattkruse.com/javascript/dynamicoptionlist/index.html

我現在有兩個問題： 由於有24個省，86個區， 1600個公社和13500個村莊，爲下拉框創建需要幾秒鐘的時間。

的表格如下所示（省）：

country_id province_id province_en province_kh 
000000 010000   Banteay Mean Chey Khmer 1 
000000 020000   Bat Dambang Khmer 2 
000000 030000   Kampong Cham  Khmer 3 
000000 040000   Kampong Chhnang Khmer 

（區） province_id district_id district_en district_kh 010000 010200 Mongkol博瑞高棉1 010000 010300普農Srok高棉2 010000 010400柏威夏NETR柏威夏高棉3 010000 010500 Ou Chrov高棉4

...同樣的公社和村莊。

我通過獲取值了微軟的SQL Server：

$sqlProvinces = "SELECT country_id, province_id, province_en, province_kh FROM dbo.vhp"; 
$sqlDistricts = "SELECT province_id, district_id, district_en, district_kh FROM dbo.vhd"; 

...同爲鄉鎮和村莊。

就像在我的評論中提到，我存儲在$ _SESSION這些值：

$_SESSION["provincesresults"]=$provincesResults; 
$_SESSION["districtsresults"]=$districtsResults; 

之後，我使用的功能「dyndrpdwn。PHP的 「生成下拉列表：

<?php 

function dyndrpdwn() { 

    //count the number of provinces, districts, communes and villages for the counters of the for-statements 
    $countProvinces = count($_SESSION["provincesresults"]); 
    $countDistricts = count($_SESSION["districtsresults"]); 
    $countCommunes = count($_SESSION["communesresults"]); 
    $countVillages = count($_SESSION["villagesresults"]); 

    //NULL the return values 
    $returnPD = NULL; 
    $returnC = NULL; 
    $returnV = NULL; 
    $defaultP = NULL; 
    $defaultD = NULL; 
    $defaultC = NULL; 
    $defaultV = NULL; 

    //Set start value for the counters to 0 
    $j = 0; 
    $k = 0; 
    $l = 0; 

    //Start the JavaScript and create the DynamitOptionList 
    $returnPD = "<script type=\"text/javascript\"> 
        var makeGeo = new DynamicOptionList(\"provinces\",\"districts\",\"communes\",\"villages\");"; 

    //Loop through all Provinces 
    for($i = 0; $i < $countProvinces; $i++) { 

     //Create the optionlist for provinces 
     $returnPD = $returnPD."makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").addOptionsTextValue("; 

     //Create the optionlist for districts ("while" if more performant than "for"!) and make sure that counter is not getting out of index 
     while($j < $countDistricts && $_SESSION["provincesresults"][$i][1] == $_SESSION["districtsresults"][$j][0]) { 

     $returnPD = $returnPD."\"".$_SESSION["districtsresults"][$j][2]."\",\"".$_SESSION["districtsresults"][$j][1]."\","; 

     $returnC = $returnC."makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").forValue(\"".$_SESSION["districtsresults"][$j][1]."\").addOptionsTextValue("; 

     //Create the optionlist for communes ("while" if more performant than "for"!) and make sure that counter is not getting out of index 
     while($k < $countCommunes && $_SESSION["districtsresults"][$j][1] == $_SESSION["communesresults"][$k][0]) { 

      $returnC = $returnC."\"".$_SESSION["communesresults"][$k][2]."\",\"".$_SESSION["communesresults"][$k][1]."\","; 

      $returnV = $returnV."makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").forValue(\"".$_SESSION["districtsresults"][$j][1]."\").forValue(\"".$_SESSION["communesresults"][$k][1]."\").addOptionsTextValue("; 

      //Create the optionlist for villages ("while" if more performant than "for"!) and make sure that counter is not getting out of index 
      while($l < $countVillages && $_SESSION["communesresults"][$k][1] == $_SESSION["villagesresults"][$l][0]) { 

       $returnV = $returnV."\"".$_SESSION["villagesresults"][$l][2]."\",\"".$_SESSION["villagesresults"][$l][1]."\","; 

       //Set the Default Value 
      $defaultV = "makeGeo.forValue(\"".$_SESSION["communesresults"][$k][1]."\").setDefaultOptions(\"".$_SESSION["searchresultspmd"][0][8]."\");"; 

       //Increase the counter by 1 
       $l++; 
      } 

      //Cut the last "," of the string after the last value of $returnC 
      $returnV = substr($returnV, 0, -1); 

      //Close the JavaScript statement 
      $returnV = $returnV.");"; 

      //If there is no village for the commune, remove the already prepared string "makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").forValue(\"".$_SESSION["districtsresults"][$j][1]."\").forValue(\"".$_SESSION["communesresults"][$k][1]."\").addOptionsTextValue(" 
      if(substr($returnV,-21) == "addOptionsTextValue);") { 

       $returnV = substr($returnV, 0, -86); 
      } 

      //Set the Default Value 
      $defaultC = "makeGeo.forValue(\"".$_SESSION["districtsresults"][$j][1]."\").setDefaultOptions(\"".$_SESSION["searchresultspmd"][0][7]."\");"; 

      //Increase the counter by 1 
      $k++; 
     } 

     //Cut the last "," of the string after the last value of $returnC 
     $returnC = substr($returnC, 0, -1); 

     //Close the JavaScript statement 
     $returnC = $returnC.");"; 

     //If there is no commune for the district, remove the already prepared string "makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").forValue(\"".$_SESSION["districtsresults"][$j][1]."\").addOptionsTextValue(" 
     if(substr($returnC,-21) == "addOptionsTextValue);") { 

      $returnC = substr($returnC, 0, -66); 
     } 

     //Set the Default Value 
     $defaultD = "makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").setDefaultOptions(\"".$_SESSION["searchresultspmd"][0][8]."\");"; 

     //Increase the counter by 1 
     $j++; 
     } 

     //Cut the last "," of the string after the last value of $returnPD 
     $returnPD = substr($returnPD, 0, -1); 

     //Close the JavaScript statement 
     $returnPD = $returnPD.");"; 

     //If there is no district for the province, remove the already prepared string "makeGeo.forValue(\"".$_SESSION["provincesresults"][$i][1]."\").addOptionsTextValue(" 
     if(substr($returnPD,-21) == "addOptionsTextValue);") { 

     $returnPD = substr($returnPD, 0, -47); 
     } 

     //Set the Default Value 
     $defaultP = "makeGeo.forValue(\"provinces\").setDefaultOptions(\"".$_SESSION["provincesresults"][$i][1]."\");"; 
    }    

    //Put Provinces, Districts, Communes and Villages together and close the Javascript 
    $returnPDCV = $returnPD.$returnC.$returnV.$defaultD.$defaultC.$defaultV."</script>"; 

    //Return the result 
    return sprintf($returnPDCV); 
} 
?> 

爲了使用JavaScript，我用在patient_update.php下面的代碼：

//include the dynamic drop down generator 
include("/functions/dyndrpdwn.php"); 

<!--Adding JavaScript for dynamic dropdown list--> 
<script type=\"text/javascript\" src=\"/js/dynamicoptionlist.js\"></script> 

//Call the dynamic drop down function 
echo dyndrpdwn(); 

echo"<!--Province Create Drop-Down Field--> 
    <select name=\"provinces\" class =\"dropdown\">"; 

//Fill the drop down, when data is received by get_value_help.php or if session array is already filled 
if(isset($_GET["value"]) == "true" && $_GET["value"] == "receive" || isset($_SESSION["provincesresults"]) == "true" && count($_SESSION["provincesresults"]) > 0) { 

    //Get all the values out of the Province array out of pdo.vhd 

$ countProvinces =計數（$ _ SESSION [」 provincesresults「]）;

for($i=0; $i < $countProvinces; $i++) { 

     //Display the Khmer or the English language depending on the website settings. $_SESSION["searchresultspmd"][0][5]) = province_id in dbo.pmd 
     //$_SESSION["provincesresults"][$i][1] = province_id in dbo.vhp 
     if(isset($_SESSION["lng"]) == "true") { 

     switch ($_SESSION["lng"]) { 

      case "english": 

       if($_SESSION["provincesresults"][$i][2] == $_SESSION["searchresultspmd"][0][5]) { 

        echo"<option value=".$_SESSION["provincesresults"][$i][1]." SELECTED>"; 
       } 
       else { 

        echo"<option value=".$_SESSION["provincesresults"][$i][1].">"; 
       } 

       echo"".$_SESSION["provincesresults"][$i][2]." 
        </option>"; 
       break; 

      case "khmer": 

       if($_SESSION["provincesresults"][$i][2] == $_SESSION["searchresultspmd"][0][5]) { 

        echo"<option value=".$_SESSION["provincesresults"][$i][1]." SELECTED>"; 
       } 
       else { 

        echo"<option value=".$_SESSION["provincesresults"][$i][1].">"; 
       } 

       echo"".$_SESSION["provincesresults"][$i][3]." 
        </option>"; 
       break; 
     } 
     } 
    } 
} 

echo"   </select> 
      </td> 
      <td> 

       <!--District Create Drop-Down Field--> 
       <select name=\"districts\" class =\"dropdown\"> 
        <script type=\"text/javascript\"> 
        makeGeo.printOptions(\"districts\") 
        </script> 
       </select> 
      </td> 
      <td> 

       <!--Commune Create Drop-Down Field--> 
       <select name=\"communes\" class =\"dropdown\"> 
        <script type=\"text/javascript\"> 
        makeGeo.printOptions(\"communes\") 
        </script> 
       </select> 
      </td> 
      <td> 

       <!--Village Create Drop-Down Field--> 
       <select name=\"villages\" class =\"dropdown\"> 
        <script type=\"text/javascript\"> 
        makeGeo.printOptions(\"villages\") 
        </script> 
       </select> 
      </td> 

...

因此，有兩個問題，現在：

1. 調用dyndrpdwn.php函數需要幾秒鐘的時間，因爲有〜24個省，〜86個區，〜1600個社區和〜13500個村莊和我循環它們。有沒有辦法改善性能？
2. With setDefaultOptions我嘗試爲正確的下拉列表設置默認值。但在我的代碼中不起作用。我將它與[JavaScript網站] [1]上的示例進行了比較，但是我找不到錯誤...您能否看到它爲什麼不能像我這樣做？

結果目前看起來像這樣：

<script type="text/javascript"> 
var makeGeo = new DynamicOptionList("provinces","districts","communes","villages"); 

這將創建一個省份和地區的條目：

makeGeo.forValue("010000").addOptionsTextValue("Mongkol Borei","010200","Phnum Srok","010300","Preah Netr Preah","010400","Ou Chrov","010500","Serei Saophoan","010600","Thma Puok","010700","Svay Chek","010800","Malai","010900"); 

這對公社創建條目

makeGeo.forValue("010000").forValue("010200").addOptionsTextValue("Banteay Neang","010201","Bat Trang","010202","Chamnaom","010203","Kouk Ballangk","010204","Koy Maeng","010205","Ou Prasat","010206","Phnum Touch","010207","Rohat Tuek","010208","Ruessei Kraok","010209","Sambuor","010210","Soea","010211","Srah Reang","010212","Ta Lam","010213"); 

這創建了村莊的條目：

makeGeo.forValue("010000").forValue("010200").forValue("010201").addOptionsTextValue("Ou Thum","01020101","Phnum","01020102","Banteay Neang","01020103","Kouk Pnov","01020104","Trang","01020105","Pongro","01020106","Kouk Tonloab","01020107","Trabaek","01020108","Khile","01020109","Samraong Pen","01020110","Dang Run Lech","01020111","Dang Run Kaeut","01020112","Ou Snguot","01020113","Prey Changha Lech","01020114","Prey Changha Kaeut","01020115","Ou Andoung Lech","01020116","Ou Andoung Kandal","01020117","Ou Andoung Kaeut","01020118","Kouk Kduoch","01020119"); 

而這應該設置省，區和公社的默認值（只有3個例子;他們沒有工作至今...）：

makeGeo.forValue("240000").setDefaultOptions("Boeng Trakuon"); 
makeGeo.forValue("240200").setDefaultOptions("Ou Andoung"); 
makeGeo.forValue("240204").setDefaultOptions("Boeng Trakuon");</script> 

<!--Province Create Drop-Down Field--> 
<select name="provinces" class ="dropdown"> 
    <option value=010000>Banteay Mean Chey 
    </option><option value=020000>Bat Dambang 
    </option><option value=030000>Kampong Cham 
    </option><option value=040000>Kampong Chhnang 
    </option><option value=050000>Kampong Spueu 
    </option><option value=060000>Kampong Thum 
    </option><option value=070000>Kampot 
    </option><option value=080000>Kandal 
    </option><option value=090000>Kaoh Kong 
    </option><option value=100000>Kracheh 
    </option><option value=110000>Mondol Kiri 
    </option><option value=120000>Phnom Penh 
    </option><option value=130000>Preah Vihear 
    </option><option value=140000>Prey Veaeng 
    </option><option value=150000>Pousat 
    </option><option value=160000>Rotanak Kiri 
    </option><option value=170000>Siem Reab 
    </option><option value=180000>Krong Preah Sihanouk 
    </option><option value=190000>Stueng Traeng 
    </option><option value=200000>Svay Rieng 
    </option><option value=210000>Takaev 
    </option><option value=220000>Otdar Mean Chey 
    </option><option value=230000>Krong Kaeb 
    </option><option value=240000 SELECTED>Krong Pailin 
    </option></select> 

    </td> 
    <td> 

     <!--District Create Drop-Down Field--> 
     <select name="districts" class ="dropdown"> 
     <script type="text/javascript"> 
      makeGeo.printOptions("districts") 
     </script> 
     </select> 
    </td> 
    <td> 

     <!--Commune Create Drop-Down Field--> 
     <select name="communes" class ="dropdown"> 
     <script type="text/javascript"> 
      makeGeo.printOptions("communes") 
     </script> 
     </select> 
    </td> 
    <td> 

     <!--Village Create Drop-Down Field--> 
     <select name="villages" class ="dropdown"> 
     <script type="text/javascript"> 
      makeGeo.printOptions("villages") 
     </script> 
     </select> 
    </td> 

我知道它的相當多的東西，通過看，對不起那個butevery幫助高度讚賞！

Answer 1

不幸的是，上面概述的方法不起作用。當你在一個javascript段中使用php時，你必須記住，只有當從服務器請求包含javascript的文件時纔會評估php代碼。 PHP代碼在請求期間輸出的任何內容（例如，通過'echo'命令）將成爲您的javascript函數的一部分。在上面的情況下，你沒有輸出任何東西，所以一旦頁面加載，你的javascript代碼基本上會讀取.innerHTML=\" \";。即使你在那裏輸出數據，它也不會是動態的。

在我看來，你有3種選擇：

1. 使用AJAX來加載從一個PHP文件中的第二個下拉的HTML。如果你已經熟悉AJAX，這絕對是一種方式，否則可能會有點棘手。如果你不熟悉，我肯定會建議在嘗試實現這個選項之前通過幾個教程。

2. 當用戶更改第一個下拉列表時重新載入頁面，並使用查詢字符串參數告訴您的PHP腳本選擇了哪個省份。這可能不是一個很好的選擇，特別是如果這對下拉菜單是用戶可能已經輸入了一些數據的更大形式的一部分。

3. 讓您的PHP輸出第一個下拉菜單的HTML，然後單獨列出每個省的下拉菜單，列出各自的區域。 （因此，如果你有10個省份，總共可以創建11個下拉菜單。）然後，您將使用CSS樣式display: none;來隱藏輔助下拉菜單，並使用javascript將其樣式切換爲display: inline-block;。此選項不適用於大量選項，因爲您正在加載大量可能不必要的數據。

出於好奇，爲什麼要將省數據存儲在用戶的$_SESSION變量中？我通常會嘗試爲用戶特定的數據或有關接口狀態的信息進行預留。