Is It Possible To Do String Substitution In Android Resource Xml Files Directly?

In my android app, I have a large string resource xml file. I want to make reference and reuse declared resources values within String values. Is it possible to have the R class

Solution 1:

Add a %s to your second resource string (the one that you want to be dynamic) where you want it to be modified. i.e.,

<resources>
<string name="db_table_name">tbl_name</string>
<string name="ddl">createtable %s</string>
</resources>

and in your code use getString() to work the magic,

getString(R.string.ddl, getString(R.string.db_table_name));

Solution 2:

It's indeed possible.

<?xml version="1.0" encoding="utf-8"?><!DOCTYPE resources [
  <!ENTITY appname"MyAppName"><!ENTITY author"MrGreen">
]><resources><stringname="app_name">&appname;</string><stringname="description">The &appname; app was created by &author;</string></resources>

You can even define your entity globaly e.g:

res/raw/entities.ent:

<!ENTITY appname"MyAppName"><!ENTITY author"MrGreen">

res/values/string.xml:

<?xml version="1.0" encoding="utf-8"?><!DOCTYPE resources [
    <!ENTITY % entsSYSTEM"./res/raw/entities.ent">
    %ents;   
]><resources><stringname="app_name">&appname;</string><stringname="description">The &appname; app was created by &author;</string></resources>

Solution 3:

Yes, it is possible without writing any Java/Kotlin code, only XML, by using this small library I created which does so at buildtime: https://github.com/LikeTheSalad/android-string-reference

Usage

Based on your example, you'd have to set your strings like this:

<resources>
  <string name="db_table_name">tbl_name</string>
  <string name="template_ddl">createtable ${db_table_name}</string>
</resources>

And then, after building your project, you'll get:

<resources>
  <string name="ddl">createtable tbl_name</string>
</resources>

Solution 4:

Well, I don't think this is possible. Because once the resources are allocated android won't allow us to change them dynamically in the air. Instead you can try having your Strings in a separate class and change them as you run through your code.