If you specifically know which user to associate and using a query to retrieve the user Id then there are multiple places like custom labels/ custom settings where you can save the Id's and use a map/ string and pull the ID value
say for eg. When you have to assign a region to a particular salesrep and the rep is not constant,all you do is:
Create a custom setting ( my choice) and save North america and put the user id as the Salesforce user id of the rep.
Lookup on how to create a custom setting and manage data.
If at all you feel custom settings are hard to get at the first go try custom labels. This is one way you can minimize hard coding.
In your apex class you can do :
String user_Id = Label.North_america_Rep_ID;
post.some_user_Id__c =u.id;
In the VF page you can do the same as
UPDATE:
This is how you make use of custom settings
step 1: Go to Setup--> Develope --> custom setting --> New
Once you hit new this is similar to creating a new custom object in salesforce.
step2: Name the custom setting and set
Settting Type : List
Visibility : Public
save the new custom setting
Step3: create a new custom field and choose "text" and hit next and save.
Step4: Once save is compelete go back to the custom setting and then click on manage.
Step5: You should be able to see 2 fields 1) Name 2) custom field you created
Think of this as a dictionary
Name My custom Field
user1 005user1id
user2 005user2id
user3 005user3id
Once you have set up your custom setting you can use the custom setting in your apex as below
map<string,string> Custom_setting_map = new map<string,string>();
//Get all the values from the custom setting.
for(customsetting custom: customsettingname.getall().values()){
Custom_setting_map.put(custom.name,custom.my_custom_field__c);
}
and then for the user1 you can do
string user_id = '';
//get current user's username and check if the custom setting has the username in the key.
if(custom_setting_map.containsKey(userinfo.getusername()){
user_id = custom_setting_map.get(u.name));
}
