EasyUI combobox determines whether the input item exists in the drop-down list

combobox Of getValue The method is strange , When the input item exists in the drop-down list , What is returned is what is needed ID, But when the input item does not exist in the drop-down list , But directly return the user's input results . This makes it impossible to determine whether the user has entered an item that does not exist in the drop-down box .

I thought of direct judgment for the first time getValue Get whether it is an integer string , As a result, the user may just enter a number that does not exist in the drop-down list , Will stay BUG hidden danger .

Several methods found by Baidu are similar , Basically in combobox Of onHidePanel（ The drop-down list hides Events ） Incident , Compare the user input value with the list to determine whether there is . But I feel this method is not easy to use .

Actually , Think about it carefully , Now that the user input is correct ,getValue Can return correctly ID, There must be a traversal process inside the plug-in , Why should we go through it again outside ？ Directly modify the plug-in , Let him getValue In error input, it directly returns null , No, you can judge directly getValue Is it blank to confirm whether the user input exists in the drop-down list ？

Check easyui Source code （1.9.15） After the discovery , In this part , There is indeed a variable （_b63）, First assign the user input string , Then go through all the drop-down lists , If it exists in the drop-down list, reassign the variable to ID Field .

Here, you only need to change the variable to null by default , In this way, under the wrong input of the user ,getValue You get a null value , Directly confirm whether the user has entered an option that does not exist in the drop-down list by judging the null value .

Of course , Feeling easyui This strange practice , Maybe it's because there's something to deal with . Maybe it's for compatibility. The drop-down list is not bound ID Field , Only text Can correctly obtain text Content ？ Anyway, my drop-down lists are bound ID Field , Let's use it first ~