MOGenerator is a command line utility that generates NSManagedObject class files based on you model files. It creates a NSManagedObject derived class for each entity of your model.
The utility can be run manually every time you change your model files (.xcdatamodeld).
This manual process can easily be forgotten, and ideally we want it to automatic regenerate the files every time you change the model.
We can use XCode Build Rules to add an extra step on the processing of model files. So every time you change them XCode itself will run MOGenerator and generate new files.
To do this follow this steps:
- Create a folder inside your project called MOGenerator and copy the mogenerator binary file inside. I normally place it inside a folder called Libraries/MOGenerator inside the project. If you are a GIT user you can setup it as a git submodule in your project .
- Open the Project settings view, select your target, open the Build Rules tab.
- Add two new build rules, one for “Data model files” and another for “Data model version files” this is done be selecting the Process dropdown.
- Change the Using dropdown to Custom Script
- Add the following code to the script text box. (Here is a list of all XCode environment variables).
- For Data model files:
mogenerator --model "${INPUT_FILE_PATH}" --output-dir "${PROJECT_DIR}/XXXXX/Source/Model" --template-var arc=true
${DEVELOPER_BIN_DIR}/momc -XD_MOMC_TARGET_VERSION=10.7 "${INPUT_FILE_PATH}" "${TARGET_BUILD_DIR}/${EXECUTABLE_FOLDER_PATH}/${INPUT_FILE_BASE}.mom"
- For Data model version Files:
mogenerator --model "${INPUT_FILE_PATH}" --output-dir "${PROJECT_DIR}/XXXXX/Source/Model" --template-var arc=true
${DEVELOPER_BIN_DIR}/momc -XD_MOMC_TARGET_VERSION=10.7 "${INPUT_FILE_PATH}" "${TARGET_BUILD_DIR}/${EXECUTABLE_FOLDER_PATH}/${INPUT_FILE_BASE}.momd"
- Change the output-dir parameter to your specific generation path. This is the path where mogenerator will save the files.
- Set the Output Files to the following values:
- Data model Files:
$(DERIVED_FILE_DIR)/$(INPUT_FILE_BASE).mom
- Data Model Version Files:
$(DERIVED_FILE_DIR)/$(INPUT_FILE_BASE).momd
- Next step is to enter the name of the Class for your entity. Entity name and Class have to be the same
- Build the project and check if you don’t get any failures in the build process.
- Any entities which are new (that is, which MOGenerator has not encountered in a previous build) will need to be manually added to your project. This step only needs to be performed when you have new entities, not during updates to existing entities.
- If you have multiple targets in your project which utilize your data model, you’ll need to add these build steps for each target to make sure the model is kept up to date for each target. If this is the case you could consider to move the script commands to an external script file and refer to it on the shell script in XCode.
