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.getIterator

Last edited by Mark Hamstra on Oct 2, 2017.

xPDO::getIterator

Retrieves an xPDOIterator representing an iterable collection of xPDOObjects by the specified xPDOCriteria.

Use an xPDOIterator to loop over large result sets and work with one instance at a time. This greatly reduces memory usage over loading the entire collection of objects into memory at one time. It is also slightly faster.

Syntax

xPDOIterator getIterator (string $className, [xPDOCriteria|array|str|int $criteria = null], [bool|int $cacheFlag = true])

Remember, if you are using xPDO map and class files that were generated from XML schema, the classname is not the same as your table name. If in doubt, have a look at the schema XML file, e.g.

<object class="MyClassName" table="my_class_name" extends="xPDOObject">

Example

Get an iterator for a collection of Box objects with a width of 40.

$boxes = $xpdo->getIterator('Box',array(
   'width' => 40,
));
foreach ($boxes as $idx => $box) {
    echo "Box #{$idx} has an id of {$box->get('id')} and a width of {$box->get('width')}\n";
}

If no matching xPDOObjects are found, the xPDOIterator object will be empty but will still be an object, so the following won't work (opposed to xPDO.getCollection):

// a parent of -1 doesn't exist, this is intentional =)
$resourceObjs = $xpdo->getIterator('modResource', array('parent' => -1));
if ($resourceObjs) { // the same goes for if (!empty($resourceObjs)
    // this will always run, as the $resourceObjs is never empty
    // in the sense we would intuitively think of empty
    // the $resourceObjs contains an empty xPDOIterator object, but it's not an empty array!
}
// if you really need to check if there's something to iterate, you could do either:
if ($xpdo->getCount('modResource', array('parent' => -1))) {
    // this will not run
}
// or
$resourceObjs->rewind();
if ($resourceObjs->valid()) {
    // this will not run
}

See Also

Comment Policy

Comments intended to help 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.

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