fulcro.client.impl.parser — fulcrologic/fulcro 2.6.15

Generic query expression parsing and AST manipulation.

QUERY EXPRESSIONS

Query expressions are a variation on Datomic Pull Syntax http://docs.datomic.com/pull.html more suitable for generic client/server state transfer. It's important to note the query expression syntax is not a strict superset of Datomic Pull.

A query expression is composed of EDN values. The grammar for query expressions follows:

QueryRoot := EdnVector(QueryExpr*) PlainQueryExpr := (EdnKeyword | IdentExpr | JoinExpr) QueryExpr := (PlainQueryExpr | ParamExpr) IdentExpr := EdnVector2(Keyword, EdnValue) ParamExpr := EdnList2(PlainQueryExpr | EdnSymbol, ParamMapExpr) ParamMapExpr := EdnMap(Keyword, EdnValue) JoinExpr := EdnMap((Keyword | IdentExpr), (QueryRoot | UnionExpr | RecurExpr)) UnionExpr := EdnMap(Keyword, QueryRoot) RecurExpr := ('... | Integer)

Note most of the api expects a QueryRoot not a QueryExpr.

QUERY EXPRESSION AST FORMAT

Given a QueryExpr you can get the AST via om.next.impl.parser/expr->ast. The following keys can appear in the AST representation:

{:type (:prop | :join | :call | :root | :union | :union-entry) :key (EdnKeyword | EdnSymbol | IdentExpr) :dispatch-key (EdnKeyword | EdnSymbol) :union-key EdnKeyword :query (QueryRoot | RecurExpr) :params ParamMapExpr :children EdnVector(AST) :component Object :target EdnKeyword}

:query and :params may or may not appear. :type :call is only for mutations.

ast->expr clj/s

(ast->expr ast)

(ast->expr {:keys [type component] ast-meta :meta :as ast} unparse?)

Given a query expression AST convert it back into a query expression.

call->ast clj/s

(call->ast [f args :as call])

dispatch clj/s

(dispatch _ k _)

expr->ast clj/s

(expr->ast x)

Given a query expression convert it into an AST.

ident->ast clj/s

(ident->ast [k id :as ref])

join->ast clj/s

(join->ast join)

keyword->ast clj/s

(keyword->ast k)

parameterize clj/s

(parameterize expr params)

parser clj/s

(parser {:keys [read mutate] :as config})

Given a :read and/or :mutate function return a parser. Refer to fulcro.client.primitives/parser for top level documentation.

path-meta clj/s

(path-meta data path query)

(path-meta data path query union-expr)

Add path metadata to a data structure. data is the data to be worked on. path is the current path into the data. query is the query used to walk the data. union-expr tracks the last seen union query to be used when it finds a recursive union.

query->ast clj/s

(query->ast query)

Convert a query to its AST representation.

rethrow? clj/s

(rethrow? x)

substitute-root-path-for-ident clj/s

(substitute-root-path-for-ident data-tree replacement-root-path query)

Given the result (and query) of an ident-based query like:

[{[:TABLE :ID] (get-query C)}]

a query response data tree:

{ [:TABLE :ID] { ...props for C...} }

and a replacement-root-path such as [:ROOT/subcomponent :subcomponent/items 0], adds path metadata to the val (props for C) of that data tree as-if it had been queried from the UI root (replacement-root-path). E.g. the path metadata on the val (props of C) will START at replacement-root-path.

symbol->ast clj/s

(symbol->ast k)

union->ast clj/s

(union->ast m)

union-entry->ast clj/s

(union-entry->ast [k v])

wrap-expr clj/s

(wrap-expr root? expr)