Hui 辉

Hui 辉 (“shine” in Chinese) is a Solr client and library for Elixir.
Usage
Hui enables Solr querying and other forms of interaction (forthcoming) in Elixir or Phoenix applications. Typical Solr data can be contained within a core (index) held on a single server or a data collection in distributed server architecture (cloud).
Example
Hui.q("scott") # keywords search
Hui.q(q: "loch", rows: 5) # arbitrary keyword list
Hui.q(%Hui.Q{q: "loch", rows: 5, start: 20}) # structured query
Hui.q(%Hui.Q{q: "author:I*", rows: 5}, %Hui.F{field: ["cat", "author_str"], mincount: 1}) # with faceting
# `:library` is a URL reference key - see below
Hui.search(:library, %Hui.Q{q: "loch", fq: ["type:illustration", "format:image/jpeg"]})
# Suggester query
suggest_query = %Hui.S{q: "ha", count: 10, dictionary: ["name_infix", "ln_prefix", "fn_prefix"]}
Hui.suggest(:library, suggest_query)
# MoreLikeThis query
query = %Hui.Q{q: "apache", rows: 10, wt: "xml"}
mlt = %Hui.M{fl: "manu,cat", mindf: 10, mintf: 200, "match.include": true, count: 10}
Hui.mlt(:library, query, mlt)
# DisMax structured query via a list of existing Hui structs
x = %Hui.D{q: "market", qf: "description^2.3 title", mm: "2<-25% 9<-3", pf: "title", ps: 1, qs: 3}
y = %Hui.Q{rows: 10, start: 10, fq: ["edited:true"]}
z = %Hui.F{field: ["cat", "author_str"], mincount: 1}
Hui.search(:library, [x, y, z])
# Add results highlighting (snippets) with `Hui.H`
x = %Hui.Q{q: "features:photo", rows: 5}
y = %Hui.H{fl: "features", usePhraseHighlighter: true, fragsize: 250, snippets: 3 }
Hui.search(:library, [x, y])
# more elaborated faceting query
x = %Hui.Q{q: "*", rows: 5}
range1 = %Hui.F.Range{range: "price", start: 0, end: 100, gap: 10, per_field: true}
range2 = %Hui.F.Range{range: "popularity", start: 0, end: 5, gap: 1, per_field: true}
y = %Hui.F{field: ["cat", "author_str"], mincount: 1, range: [range1, range2]}
Hui.search(:library, x, y)
# this spawns a request with the following query string
# q=%2A&rows=5&facet=true&facet.field=cat&facet.field=author_str&facet.mincount=1&
# f.price.facet.range.end=100&f.price.facet.range.gap=10&facet.range=price&
# f.price.facet.range.start=0&f.popularity.facet.range.end=5&
# f.popularity.facet.range.gap=1&
# facet.range=popularity&f.popularity.facet.range.start=0
The q
examples queries a default endpoint - see Configuration
below.
A query could be a string, a Keyword list or
built-in query Structs
providing a structured way for invoking the comprehensive and powerful features of Solr.
Queries may also be issued to other endpoints and request handlers:
# URL binary string
Hui.search("http://localhost:8983/solr/collection", %Hui.Q{q: "loch"})
# URL key referring to an endpoint in configuration - see "Configuration"
url = :library
Hui.search(url, q: "edinburgh", rows: 10)
# URL in a struct
url = %Hui.URL{url: "http://localhost:8983/solr/collection", handler: "suggest"}
Hui.search(url, suggest: true, "suggest.dictionary": "mySuggester", "suggest.q": "el")
# this -> http://http://localhost:8983/solr/collection/suggest?suggest=true&suggest.dictionary=mySuggester&suggest.q=el
See the API reference and Solr reference guide for more details on available search parameters.
HTTP headers and options
HTTP headers and options can be specified via the Hui.URL.t/0
struct.
# setting up a header and a 10s receiving connection timeout
url = %Hui.URL{url: "..", headers: [{"accept", "application/json"}], options: [recv_timeout: 10000]}
Hui.search(url, q: "solr rocks")
Headers and options for a specific endpoint may also be configured - see “Configuration”.
Software library
Hui modules and data structures can be used for building Solr application in Elixir and Phoenix.
The following struct modules provide an idiomatic and structured way for creating and encoding Solr parameters:
- Standard and common query:
Hui.Q
- DisMax query:
Hui.D
- Faceting:
Hui.F
,Hui.F.Range
,Hui.F.Interval
- Results highlighting:
Hui.H
,Hui.H1
,Hui.H2
,Hui.H3
- structs for other request handlers are forthcoming
For example, instead of prefixing and repeating fq=filter
, facet.field=fieldname
, facet.range.gap=10
,
multiple filter and facet fields can be specified using
fq: ["field1", "field2"]
, field: ["field1", "field2"]
, gap: 10
Elixir codes.
“Per-field” faceting for multiple ranges and intervals can be specified in a succinct and unified
way, e.g. gap
instead of the long-winded f.[fieldname].facet.range.gap
(per field) or facet.range.gap
(single field range). Per-field use case for a facet can easily be set (or unset) with the per_field
key - see below.
x = %Hui.Q{q: "loch", fq: ["type:image/jpeg", "year:2001"], fl: "id,title", rows: 20}
x |> Hui.URL.encode_query
# -> "fl=id%2Ctitle&fq=type%3Aimage%2Fjpeg&fq=year%3A2001&q=loch&rows=20"
x = %Hui.F{field: ["type", "year", "subject"], query: "edited:true"}
x |> Hui.URL.encode_query
# -> "facet=true&facet.field=type&facet.field=year&facet.field=subject&facet.query=edited%3Atrue"
# there's no need to set "facet: true" as it is implied and a default setting in the struct
# a unified way to specify per-field or singe-field range
x = %Hui.F.Range{range: "age", gap: 10, start: 0, end: 100}
x |> Hui.URL.encode_query
# -> "facet.range.end=100&facet.range.gap=10&facet.range=age&facet.range.start=0"
x = %{x | per_field: true} # toggle per field faceting
x |> Hui.URL.encode_query
# -> "f.age.facet.range.end=100&f.age.facet.range.gap=10&facet.range=age&f.age.facet.range.start=0"
The structs also provide binding to and introspection of the available fields.
iex> %Hui.F{field: ["type", "year"], query: "year:[2000 TO NOW]"}
%Hui.F{
contains: nil,
"contains.ignoreCase": nil,
"enum.cache.minDf": nil,
excludeTerms: nil,
exists: nil,
facet: true,
field: ["type", "year"],
interval: nil,
limit: nil,
matches: nil,
method: nil,
mincount: nil,
missing: nil,
offset: nil,
"overrequest.count": nil,
"overrequest.ratio": nil,
pivot: [],
"pivot.mincount": nil,
prefix: nil,
query: "year:[2000 TO NOW]",
range: nil,
sort: nil,
threads: nil
}
Parsing Solr results
Hui returns Solr results as HTTPoison.Response
struct containing the Solr response.
{:ok,
%HTTPoison.Response{
body: "...[Solr reponse]..",
headers: [
{"Content-Type", "application/json;charset=utf-8"},
{"Content-Length", "4005"}
],
request_url: "http://localhost:8983/solr/gettingstarted/select?q=%2A",
status_code: 200
}
}
JSON response is automatically parsed and decoded as
Map.
It is accessible via the body
key.
{status, resp} = Hui.q(solr_params)
# getting a list of Solr documents (Map)
solr_docs = resp.body["response"]["docs"]
total_hits = resp.body["response"]["numFound"]
Note: other response formats such as XML, are currently being returned in raw text.
Other low-level HTTP client features
Under the hood, Hui uses HTTPoison
- an HTTP client to interact with Solr.
The existing low-level functions of HTTPoison e.g. get/1
, get/3
remain available in the Hui.Search
module.
Installation
Hui is available in Hex, the package can be installed
by adding hui
to your list of dependencies in mix.exs
:
def deps do
[
{:hui, "~> 0.5.7"}
]
end
Then run $ mix deps.get
.
Documentation can be found at https://hexdocs.pm/hui.
Configuration
A default Solr endpoint may be specified in the application configuration as below:
config :hui, :default,
url: "http://localhost:8983/solr/gettingstarted",
handler: "select", # optional
headers: [{"accept", "application/json"}], # optional
options: [recv_timeout: 10000] # optional
HTTP headers and options may also be configured.
Solr provides various request handlers for many purposes (search, autosuggest, spellcheck, indexing etc.). The handlers are configured in different custom or normative names in Solr configuration, e.g. “select” for search queries.
Additional endpoints and request handlers can be configured in Hui using arbitrary config keys (e.g. :suggester
):
config :hui, :suggester,
url: "http://localhost:8983/solr/collection",
handler: "suggest"
Use the config key in functions such as Hui.search/2
, Hui.search/3
to send queries to the endpoint
or retrieve URL settings from configuration e.g. Hui.URL.configured_url/1
.
License
Hui is released under Apache 2 License. Check the LICENSE file for more information.