A snippet for getting fields and setting placeholders.  See the GitHub page for documentation and examples.

setPlaceholders combines the usefulness of placeholders—which are rather like local variables—with a fast and versatile engine for gathering up various data: fields and TVs from a resource or any of its ancestors, children or siblings, plus several other useful things.

It provides the functionality of getResourceField, UltimateParent, and getUrlParam—in addition to quite a bit more—all in one lightweight and very efficient package.  Something of a Swiss Army knife for navigating the resource tree and retrieving info.

Installation Instructions

Download and install.  The package contains one snippet called setPlaceholders.  It's that easy.

2.2.1-pl [25.03.2014]

• Add short convenience aliases for setPlaceholders snippet: sph and spho (with &output=`1`)

2.2.0-pl

• Add the ability to process more than one fallback/default value
• Add a request selector for stuff from the $_REQUEST superglobal
• Add parents and parentsI selectors for returning a list of parent IDs from the ultimate parent down to the resource
• Add bounded versions of the parent and Uparent selectors

2.1.0-pl

• [#2] Add the ability to chain child selectors. Ex: child-1.child2.pagetitle (pagetitle of the 2nd child of the current resource's last child)
• add a migxR/jsonR selector to get a random item from a MIGX TV.

2.0.1-pl

• fixes a bug with the parent selector

2.0.0-pl

• ~3x faster TV handling, now doesn't process them by default
• adds next/prev sibling selectors. next2 selects the sibling after next, etc.
• adds a "random child" selector, plus simple ways of retrieving the number of children or parents a resource has, a resource's position amongst its siblings, or the number of items a MIGX TV contains.
• memory usage improvements

N O T E   T H E S E   C H A N G E S:

• Removes &fields property (deprecated since v1.1)
• Now does not process TVs by default. Use &processTVs=`1` if you need to process them.
• Removes output filter functionality. Use the built-in output filter toPlaceholder instead. It works exactly the same.
• If you specify an index on the parent, Uparent, child, next or prev selector which is out of bounds, setPlaceholders now returns an empty string, which makes specifying a default value easier.

1.2.1-pl

• Improves child selector performance
• Changes behavior when a value isn't found for a placeholder: now the placeholder will be set to an empty string so MODX will fully parse and cache it.
• A few other minor fixes and improvements

1.2.0-pl

• Adds a child resource selector. Ex: child4.pagetitle (4th child) or child-1.pagetitle (last child)
• Adds optional special processing for MIGX TVs (arrays of JSON objects).  For example, parent.migx.someMIGXtv will set a placeholder for each key/value pair in the TV.
• Minor performance improvements

1.1.0-pl

• Added &ph property with a more powerful syntax.  It adds: "Ultimate parent" functionality, the ability to specify different resource IDs, optional user-defined placeholder names, and parsing of default values
• &fields is now deprecated, but retained for backwards compatibility
• Performance and caching improvements
• fix an issue that can generate PHP notices