1. Overview
      1. What It Is
      2. Why I Would Want to Use It
      3. Known Issues
    2. Getting Started
      1. Fundamentals
        1. Design Patterns
        2. xPDO, the Class
          1. As Object and Relational Mapper
          2. As PDO Wrapper
          3. As Service Layer
          4. The xPDO Constructor
            1. Hydrating Fields
      2. Introduction to the xPDO Object Model
        1. Understanding xPDOCriteria and xPDOQuery
      3. Creating a Model With xPDO
        1. Defining a Schema
          1. Defining Relationships
          2. Defining the Database and Tables
            1. Upgrading Models to Schema Version 1.1
          3. More Examples of xPDO XML Schema Files
          4. Validation Rules in your Schema
        2. Generating the Model Code
          1. Domain Classes
          2. O-R Maps
          3. Table Classes
      4. Using Your xPDO Model
        1. Creating Objects
        2. Database Connections and xPDO
        3. Loading Packages
        4. Removing Objects
          1. removeCollection
        5. Retrieving Objects
          1. getCollectionGraph
        6. Setting Object Fields
        7. Working with Related Objects
    3. Extending Your xPDO Model
      1. Overriding Derived Behavior
        1. Using Custom Object Loaders
      2. Working With Transient Object Classes
    4. Advanced Features
      1. Caching
        1. Caching Tutorial - Basic Snippets
        2. Caching Tutorial - Lifetimes
      2. Object Validation
        1. xPDOForeignKeyConstraint
        2. xPDOMaxLengthValidationRule
        3. xPDOMaxValueValidationRule
        4. xPDOMinLengthValidationRule
        5. xPDOMinValueValidationRule
        6. xPDOObjectExistsValidationRule
    5. xPDO Development
      1. Testing
      2. Building
      3. Documentation and Tutorials
    6. Class Reference
      1. xPDO
        1. xPDO.addPackage
        2. xPDO.beginTransaction
        3. xPDO.commit
        4. xPDO.connect
        5. xPDO.fromJSON
        6. xPDO.getCollection
        7. xPDO.getCollectionGraph
        8. xPDO.getCount
        9. xPDO.getDebug
        10. xPDO.getFields
        11. xPDO.getIterator
        12. xPDO.getManager
        13. xPDO.getObject
        14. xPDO.getObjectGraph
        15. xPDO.getOption
        16. xPDO.getTableName
        17. xPDO.loadClass
        18. xPDO.log
        19. xPDO.newObject
        20. xPDO.newQuery
        21. xPDO.query
        22. xPDO.setDebug
        23. xPDO.setLogLevel
        24. xPDO.setLogTarget
        25. xPDO.setOption
        26. xPDO.toJSON
      2. xPDOCacheManager
        1. xPDOCacheManager.copyFile
        2. xPDOCacheManager.copyTree
        3. xPDOCacheManager.delete
        4. xPDOCacheManager.deleteTree
        5. xPDOCacheManager.endsWith
        6. xPDOCacheManager.escapeSingleQuotes
        7. xPDOCacheManager.get
        8. xPDOCacheManager.getCachePath
        9. xPDOCacheManager.getCacheProvider
        10. xPDOCacheManager.matches
        11. xPDOCacheManager.replace
        12. xPDOCacheManager.set
        13. xPDOCacheManager.writeFile
        14. xPDOCacheManager.writeTree
      3. xPDOGenerator
        1. xPDOGenerator.parseSchema
        2. xPDOGenerator.writeSchema
      4. xPDOManager
        1. xPDOManager.createObjectContainer
        2. xPDOManager.createSourceContainer
        3. xPDOManager.removeObjectContainer
        4. xPDOManager.removeSourceContainer
      5. xPDOObject
        1. Configuration Accessors
          1. getOption
          2. setOption
        2. Field Accessors
          1. fromArray
          2. fromJSON
          3. get
          4. set
          5. toArray
          6. toJSON
        3. Metadata Accessors
          1. getFieldName
          2. getFKClass
          3. getFKDefinition
          4. getPK
          5. getPKType
          6. getSelectColumns
        4. Persistence Methods
          1. remove
          2. save
        5. Related Object Accessors
          1. addMany
          2. addOne
          3. getMany
          4. getOne
        6. State Accessors
          1. isDirty
          2. isLazy
          3. isNew
        7. Static Object Loaders
          1. _loadCollectionInstance
          2. _loadInstance
          3. _loadRows
          4. load
          5. loadCollection
          6. loadCollectionGraph
          7. Using Custom Loader Classes
        8. Validation
          1. addValidationRule
          2. getValidator
          3. isValidated
          4. removeValidationRules
          5. validate
      6. xPDOQuery
        1. xPDOQuery.andCondition
        2. xPDOQuery.groupby
        3. xPDOQuery.innerJoin
        4. xPDOQuery.leftJoin
        5. xPDOQuery.limit
        6. xPDOQuery.orCondition
        7. xPDOQuery.rightJoin
        8. xPDOQuery.select
        9. xPDOQuery.setClassAlias
        10. xPDOQuery.sortby
        11. xPDOQuery.where
      7. xPDORevisionControl
      8. xPDOTransport
        1. xPDOTransport.install
        2. xPDOTransport.pack
        3. xPDOTransport.uninstall
      9. xPDOValidator
        1. xPDOValidator.addMessage
        2. xPDOValidator.getMessages
        3. xPDOValidator.hasMessages
        4. xPDOValidator.validate

xPDO.getObjectGraph

Last edited by Bob Ray on Sep 2, 2017.

xPDO::getObjectGraph

Retrieves a single object instance and related objects defined by a graph, by the specified criteria.

The graph can be an array or JSON object that describes relations from the specified $className.

The criteria can be a primary key value, an array of primary key values (for multiple primary key objects) or an xPDOCriteria object. If no $criteria parameter is specified, no class is found, or an object cannot be located by the supplied criteria, null is returned.

Hot Models
In order to use getObjectGraph effectively, you need to understand the data model behind your object. It pays to keep one finger on the XML schema file that defines your objects and their relations. If you attempt to join on another object when that relationship does not exist, this method will fail!

Syntax

API Docs: http://api.modx.com/xpdo/xPDO.html#getObjectGraph

xPDOObject|null getObjectGraph (string $className, array|str $graph, [xPDOCriteria|array|str|int $criteria = null], [bool|int $cacheFlag = true])

Example using Template Variables

Before you try using this method to walk through your custom data model, here's an example of how it might be used to retrieve built-in MODX objects.

Example of what NOT to do

You may be tempted to retrieve MODX Template Variable values by using getObjectGraph:

// DO NOT DO THIS!!!  TV's have some special methods
$page = $modx->getObjectGraph('modResource', '{"TemplateVarResources":{}}',123);
$output = '';
foreach ($page->TemplateVarResources as $tv) {
    $output .= $tv->get('value');  // or do something else with this value
}
return $output;
Heads Up!
It's critical to understand that even though you may think you are retrieving a single object, that object may be joined to a collection of related objects.

You'll notice that if you use the above example to get your TV values, you'll sometimes get weird JSON encoded values that are basically unusable! The lesson? DO NOT RELY ON getObjectGraph to retrieve Template Variable values! (Unless the TV values are simple text or integers *and* no TV is set to its default value). This is important: although you may be able to retrieve some values this way, the default TV values are stored in distant corners of the database, so you should instead rely on the getTVValue helper function.

Use the getTVValue Helper Function

Instead, use the helper functions getTVValue and setTVValue:

$page = $modx->getObject('modResource', 123);
return $page->getTVValue('my_tv_name');
// or (faster)
return $page->getTVValue($tvId); // (ID of the TV)

Example

Get a Box object with ID 134, along with related BoxColors and Color instances already loaded.

$box = $xpdo->getObjectGraph('Box', array('BoxColors' => array('Color' => array())), 134);
foreach ($box->getMany('BoxColors') as $boxColor) {
    echo $boxColor->getOne('Color')->get('name');
}

The same example using a JSON-format $graph parameter.

$box = $xpdo->getObjectGraph('Box', '{"BoxColors":{"Color":{}}}', 134);
foreach ($box->getMany('BoxColors') as $boxColor) {
    echo $boxColor->getOne('Color')->get('name');
}
No additional queries
The main benefit of using getObjectGraph is to retrieve data from related tables in a single query. No additional queries are executed when getMany() or getOne() are called on the related objects that are already loaded from the $graph.

See Also

Comment Policy

These comments are not for usage questions or support. See below for support options.

Comments intended add specific value for other users with this document are welcome! Have a suggestion to improve this document? Suggest an edit (requires GitHub account). Have suggestions for code changes or feature requests? Submit to the xPDO project at GitHub..

Support Options

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