Checking whether another app is required during install

src/freedombone-utils-selector

@@ -241,6 +241,33 @@ function app_is_installed {
     fi
 }
 
+function other_app_required {
+    # is another app required before the install of this one?
+    app_name="$1"
+
+    app_filename="/usr/share/${PROJECT_NAME}/apps/${PROJECT_NAME}-app-${app_name}"
+    if [ ! -f "$app_filename" ]; then
+        echo ''
+        return
+    fi
+    if ! grep -q 'REQUIRES_APP=' "$app_filename"; then
+        echo ''
+        return
+    fi
+    grep 'REQUIRES_APP=' "$app_filename" | head -n 1 | awk -F '=' '{print $2}'
+}
+
+function check_other_app_required {
+    app_name="$1"
+    apprequired=$(other_app_required "${app_name}")
+    if [ "$apprequired" ]; then
+        if [[ $(app_is_installed "${apprequired}") != "1" ]]; then
+            echo $"${apprequired} needs to be installed before you can install ${app_name}"
+            exit 61
+        fi
+    fi
+}
+
 function install_completed_remove_progress_screen {
     local_hostname=$(grep 'host-name' /etc/avahi/avahi-daemon.conf | awk -F '=' '{print $2}').local
     webadmin_install_dir="/var/www/${local_hostname}/htdocs/admin"
@@ -696,6 +723,7 @@ function install_apps {
                         "upgrade_${a}"
                         echo $"${a} was upgraded from interactive"
                     else
+                        check_other_app_required "${a}"
                         echo $"Installing application from interactive: ${a}"
                         APP_INSTALLED=
                         function_check app_being_added_indicator
@@ -730,6 +758,7 @@ function install_apps {
                             "upgrade_${a}"
                             echo $"${a} was upgraded"
                         else
+                            check_other_app_required "${a}"
                             echo $"Installing application: ${a}"
                             APP_INSTALLED=
                             function_check app_being_added_indicator
@@ -753,6 +782,7 @@ function install_apps {
                                 APP_INSTALLED_SUCCESS=
                                 echo $"${a} was not installed"
                             fi
+
                         fi
                     else
                         echo $"${a} has been removed and so will not be reinstalled"