Class: Spider::Model::Condition
- Defined in:
- lib/spiderfw/model/condition.rb
Overview
The Condition behaves like a ModelHash, and as such contains key-value pairs: a simple equality condition can be set with
condition[:element_name] = value
The Condition object also holds comparisons: a comparison different from equality can be set with
condition.set(:element_name, '>', value)
Finally, it contains subconditions, which can be added with
conditions << subcondition
Subconditions will be created automatically when using #set twice on the same element. If you want to change the condition, use #delete and set it again.
The Condition object, like the Request, doesn’t hold a reference to a model; so no check will be made that the conditions elements are meaningful.
Instance Attribute Summary collapse
-
#comparisons ⇒ Object
readonly
An hash of comparisons for each element name.
-
#conjunct ⇒ Object
:nodoc: a hack to keep track of which is the last condition in blocks.
-
#conjunction ⇒ Object
The top level conjunction for the Condition (:or or :and; new Conditions are initialized with :or).
-
#polymorph ⇒ Object
Polymorph model: used to tell the mapper the condition is on a subclass of the queried model.
-
#subconditions ⇒ Object
readonly
An Array of subconditions.
Class Method Summary collapse
-
.and(*params, &proc) ⇒ Object
Instantiates a Condition with :and conjunction.
-
.comparison_operators_regexp ⇒ Object
Regexp to parse comparison operators.
-
.conj(conjunction, a, b) ⇒ Object
Used by and and or methods.
-
.no_conjunction(*params, &proc) ⇒ Object
Instantiates a Condition with no conjunction.
-
.or(*params, &proc) ⇒ Object
Instantiates a Condition with :or conjunction.
Instance Method Summary collapse
-
#+(condition) ⇒ Object
Returns the result of merging the condition with another one (does not modify the original condition).
-
#<<(condition) ⇒ Object
Adds a subcondtion.
- #==(other) ⇒ Object
- #[](key) ⇒ Object
-
#[]=(key, value) ⇒ Object
Sets an equality comparison.
-
#all_each_with_comparison ⇒ Object
Yields each key, value and comparison, for this condition and its subconditions.
-
#and(other = nil, &proc) ⇒ Object
(also: #&, #AND)
Joins the condition to another with an “and” conjunction.
-
#clone ⇒ Object
Returns a deep copy.
- #conditions_array ⇒ Object
-
#conditions_for(*element_names) ⇒ Object
Returns, from self and subconditions, all those who define a condition for one of the given element names.
-
#conj(conjunction, other = nil, &proc) ⇒ Object
Returns the conjunction with another condition.
-
#delete(field) ⇒ Object
Deletes a field from the Condition.
-
#each_with_comparison ⇒ Object
Yields each key, value and comparison.
-
#empty? ⇒ Boolean
True if there are no comparisons and no subconditions.
- #eql?(other) ⇒ Boolean
-
#get_deep_obj ⇒ Object
See #ModelHash.get_deep_obj.
- #hash ⇒ Object
- #hash_clone ⇒ Object
-
#hash_empty? ⇒ Object
:nodoc:.
-
#hash_replace ⇒ Object
:nodoc:.
-
#hash_set ⇒ Object
:nodoc:.
-
#initialize(*params, &proc) ⇒ Condition
constructor
Instantiates a new Condition, with :and conjunction.
- #inspect ⇒ Object
-
#or(other = nil, &proc) ⇒ Object
(also: #|, #OR)
Joins the condition to another with an “or” conjunction.
-
#parse_block(&proc) ⇒ Object
Parses a condition block.
-
#parse_comparison(comparison) ⇒ Object
Parses a string comparison.
- #polymorphs ⇒ Object
-
#range(field, lower, upper) ⇒ Object
Adds a range condition.
-
#replace(other) ⇒ Object
Replace the content of this Condition with another one.
-
#set(field, comparison, value) ⇒ Object
Sets a comparison.
-
#simplify ⇒ Object
Traverses the tree removing useless conditions.
-
#uniq! ⇒ Object
Removes duplicate subcondtions.
Constructor Details
#initialize(*params, &proc) ⇒ Condition
Instantiates a new Condition, with :and conjunction. If given a Hash, will set all keys = values. If given multiple params, will convert each to a Condition if needed, and append them to the returned instance. If a block is given, it will be processed by #parse_block
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# File 'lib/spiderfw/model/condition.rb', line 84 def initialize(*params, &proc) @conjunction = :and @comparisons = {} @subconditions = [] params.reject!{ |p| p.nil? } if (params.length == 1 && params[0].is_a?(Hash) && !params[0].is_a?(Condition)) params[0].each do |k, v| set(k, '=', v) end else # FIXME: must have an instantiate method params.each{ |item| self << (item.is_a?(self.class) ? item : self.class.new(item)) } end parse_block(&proc) if (block_given?) end |
Instance Attribute Details
#comparisons ⇒ Object (readonly)
An hash of comparisons for each element name
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# File 'lib/spiderfw/model/condition.rb', line 24 def comparisons @comparisons end |
#conjunct ⇒ Object
:nodoc: a hack to keep track of which is the last condition in blocks
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# File 'lib/spiderfw/model/condition.rb', line 27 def conjunct @conjunct end |
#conjunction ⇒ Object
The top level conjunction for the Condition (:or or :and; new Conditions are initialized with :or)
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# File 'lib/spiderfw/model/condition.rb', line 20 def conjunction @conjunction end |
#polymorph ⇒ Object
Polymorph model: used to tell the mapper the condition is on a subclass of the queried model.
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# File 'lib/spiderfw/model/condition.rb', line 22 def polymorph @polymorph end |
#subconditions ⇒ Object (readonly)
An Array of subconditions
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# File 'lib/spiderfw/model/condition.rb', line 26 def subconditions @subconditions end |
Class Method Details
.and(*params, &proc) ⇒ Object
Instantiates a Condition with :and conjunction. See #new for arguments.
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# File 'lib/spiderfw/model/condition.rb', line 58 def self.and(*params, &proc) c = self.new(*params, &proc) c.conjunction = :and return c end |
.comparison_operators_regexp ⇒ Object
Regexp to parse comparison operators
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# File 'lib/spiderfw/model/condition.rb', line 44 def self.comparison_operators_regexp # :nodoc: @comparison_operators_regexp end |
.conj(conjunction, a, b) ⇒ Object
Used by and and or methods
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# File 'lib/spiderfw/model/condition.rb', line 49 def self.conj(conjunction, a, b) # :nodoc: c = Condition.new c.conjunction = conjunction c << a c << b end |
.no_conjunction(*params, &proc) ⇒ Object
Instantiates a Condition with no conjunction.
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# File 'lib/spiderfw/model/condition.rb', line 73 def self.no_conjunction(*params, &proc) # :nodoc: c = self.new(*params, &proc) c.conjunction = nil return c end |
.or(*params, &proc) ⇒ Object
Instantiates a Condition with :or conjunction. See #new for arguments.
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# File 'lib/spiderfw/model/condition.rb', line 66 def self.or(*params, &proc) c = self.new(*params, &proc) c.conjunction = :or return c end |
Instance Method Details
#+(condition) ⇒ Object
Returns the result of merging the condition with another one (does not modify the original condition).
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# File 'lib/spiderfw/model/condition.rb', line 149 def +(condition) res = self.clone @subconditions += condition.subconditions condition.each_with_comparison do |k, v, c| res.set(k, v, c) end return res end |
#<<(condition) ⇒ Object
Adds a subcondtion.
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# File 'lib/spiderfw/model/condition.rb', line 159 def <<(condition) if (condition.class == self.class) @subconditions << condition elsif (condition.is_a?(Hash)) @subconditions << self.class.new(condition) elsif (condition.class == String) key, val, comparison = parse_comparison(condition) set(key, val, comparison) end end |
#==(other) ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 322 def ==(other) return false unless other.class == self.class return false unless super return false unless @subconditions == other.subconditions return false unless @comparisons == other.comparisons return false unless @polymorph == other.polymorph return false unless @conjunction == other.conjunction return true end |
#[](key) ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 209 def [](key) # TODO: deep key = key.name if key.is_a?(Element) key = key.to_sym if key.respond_to?(:to_sym) # might be a QueryFunc super(key) end |
#[]=(key, value) ⇒ Object
Sets an equality comparison.
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# File 'lib/spiderfw/model/condition.rb', line 205 def []=(key, value) set(key, '=', value) end |
#all_each_with_comparison ⇒ Object
Yields each key, value and comparison, for this condition and its subconditions
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# File 'lib/spiderfw/model/condition.rb', line 141 def all_each_with_comparison self.each_with_comparison{ |k, v, c| yield k, v, c } @subconditions.each do |sub| sub.all_each_with_comparison{ |k, v, c| yield k, v, c } end end |
#and(other = nil, &proc) ⇒ Object Also known as: &, AND
Joins the condition to another with an “and” conjunction. See #conj.
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# File 'lib/spiderfw/model/condition.rb', line 294 def and(other=nil, &proc) return conj(:and, other, &proc) end |
#clone ⇒ Object
Returns a deep copy.
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# File 'lib/spiderfw/model/condition.rb', line 348 def clone c = self.class.new c.conjunction = @conjunction c.polymorph = @polymorph self.each_with_comparison do |key, val, comparison| c.set(key, comparison, val) end @subconditions.each do |sub| c << sub.clone end return c end |
#conditions_array ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 125 def conditions_array self.hash_clone.map do |k, v| k = k.to_sym if k.respond_to?(:to_sym) [k, v, (@comparisons[k] || '==')] end end |
#conditions_for(*element_names) ⇒ Object
Returns, from self and subconditions, all those who define a condition for one of the given element names.
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# File 'lib/spiderfw/model/condition.rb', line 378 def conditions_for(*element_names) conds = [] element_names.each do |el| if self.key?(el) conds << self break end end @subconditions.map{ |s| s.conditions_for(*element_names) }.each{ |c| conds += c } conds end |
#conj(conjunction, other = nil, &proc) ⇒ Object
Returns the conjunction with another condition. If this condition already has the required conjunction, the other will be added as a subcondition; otherwise, a new condition will be created and both will be added to it.
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# File 'lib/spiderfw/model/condition.rb', line 268 def conj(conjunction, other=nil, &proc) self.conjunction = conjunction if (!self.conjunction) if (self.conjunction == conjunction) c = self else c = Condition.new c.conjunction = conjunction c << self end if (!other && proc) other = Condition.new(&proc) end c << other other.conjunct = true return c end |
#delete(field) ⇒ Object
Deletes a field from the Condition.
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# File 'lib/spiderfw/model/condition.rb', line 225 def delete(field) field = field.to_sym return nil unless self[field] || @comparisons[field] cur = [self[field], @comparisons[field]] super @comparisons.delete(field) cur end |
#each_with_comparison ⇒ Object
Yields each key, value and comparison.
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# File 'lib/spiderfw/model/condition.rb', line 133 def each_with_comparison self.each do |k, v| k = k.to_sym if k.respond_to?(:to_sym) yield k, v, @comparisons[k] || '=' end end |
#empty? ⇒ Boolean
True if there are no comparisons and no subconditions.
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# File 'lib/spiderfw/model/condition.rb', line 303 def empty? return false unless super @subconditions.each do |sub| return false unless sub.empty? end return true end |
#eql?(other) ⇒ Boolean
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# File 'lib/spiderfw/model/condition.rb', line 332 def eql?(other) self == other end |
#get_deep_obj ⇒ Object
See #ModelHash.get_deep_obj
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# File 'lib/spiderfw/model/condition.rb', line 31 def get_deep_obj # :nodoc: c = self.class.new c.conjunction = @conjunction return c end |
#hash ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 336 def hash ([self.keys, self.values, @comparisons.values, @polymorph] + @subconditions.map{ |s| s.hash}).hash end |
#hash_clone ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 345 alias :hash_clone :clone |
#hash_empty? ⇒ Object
:nodoc:
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# File 'lib/spiderfw/model/condition.rb', line 300 alias :hash_empty? :empty? |
#hash_replace ⇒ Object
:nodoc:
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# File 'lib/spiderfw/model/condition.rb', line 311 alias :hash_replace :replace |
#hash_set ⇒ Object
:nodoc:
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# File 'lib/spiderfw/model/condition.rb', line 28 alias :hash_set :[]= |
#inspect ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 245 def inspect str = "" cnt = 0 each do |key, value| str += " #{@conjunction} " if cnt > 0 cnt += 1 comparison = @comparisons[key] || '=' cond = "#{comparison} #{value.inspect}" str += "#{key} #{cond}" end str = '(' + str + ')' if str.length > 0 #str += ' [raw:'+raw.inspect+']' unless raw.empty? first = true if @subconditions.length > 0 str += ' '+@conjunction.to_s+' ' if str.length > 0 str += @subconditions.map{ |sub| sub.inspect }.join(' '+@conjunction.to_s+' ') end return str end |
#or(other = nil, &proc) ⇒ Object Also known as: |, OR
Joins the condition to another with an “or” conjunction. See #conj.
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# File 'lib/spiderfw/model/condition.rb', line 287 def or(other=nil, &proc) return conj(:or, other, &proc) end |
#parse_block(&proc) ⇒ Object
Parses a condition block. Inside the block, an SQL-like language can be used.
Example:
condition.parse_block{ (element1 == val1) & ( (element2 > 'some string') | (element3 .not nil) ) }
All comparisons must be parenthesized; and/or conjunctions are expressed with a single &/|.
Available comparisions are: ==, >, <, >=, <=, .not, .like, .ilike (case insensitive like).
Note: for .like and .ilike comparisons, the SQL ‘%’ syntax must be used.
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# File 'lib/spiderfw/model/condition.rb', line 110 def parse_block(&proc) res = nil if proc.arity == 1 res = proc.call(ConditionContext.new) else context = eval "self", proc.binding res = context.dup.extend(ConditionMixin).instance_eval(&proc) end self.replace(res) @conjunction = res.conjunction @comparisons = res.comparisons @subconditions = res.subconditions @polymorph = res.polymorph end |
#parse_comparison(comparison) ⇒ Object
Parses a string comparison. TODO: remove?
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# File 'lib/spiderfw/model/condition.rb', line 236 def parse_comparison(comparison) # :nodoc: if (comparison =~ Regexp.new("(.+)(#{self.class.comparison_operators_regexp})(.+)")) val = $3.strip # strip single and double quotes val = val[1..-2] if ((val[0] == ?' && val[-1] == ?') || (val[0] == ?" && val[-1] == ?") ) return [$1.strip, $2.strip, val] end end |
#polymorphs ⇒ Object
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# File 'lib/spiderfw/model/condition.rb', line 371 def polymorphs pol = [] pol << @polymorph if @polymorph return pol + @subconditions.inject([]){ |arr, s| arr += s.polymorphs } end |
#range(field, lower, upper) ⇒ Object
Adds a range condition. This creates a subcondition with >= and <= conditions.
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# File 'lib/spiderfw/model/condition.rb', line 217 def range(field, lower, upper) c = self.class.and c.set(field, '>=', lower) c.set(field, '<=', upper) self << c end |
#replace(other) ⇒ Object
Replace the content of this Condition with another one.
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# File 'lib/spiderfw/model/condition.rb', line 314 def replace(other) hash_replace(other) @subconditions = other.subconditions @conjunction = other.conjunction @polymorph = other.polymorph @comparisons = other.comparisons end |
#set(field, comparison, value) ⇒ Object
Sets a comparison.
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# File 'lib/spiderfw/model/condition.rb', line 171 def set(field, comparison, value) if value.is_a?(QuerySet) value = value.to_a end if value.is_a?(Array) && comparison != 'between' or_cond = self.class.or value.uniq.each do |v| or_cond.set(field, comparison, v) end @subconditions << or_cond return self end parts = [] unless field.is_a?(Spider::QueryFuncs::Function) field = field.to_s parts = field.split('.', 2) parts[0] = parts[0].to_sym field = field.to_sym unless parts[1] end if (parts[1]) hash_set(parts[0], get_deep_obj()) unless self[parts[0]] self[parts[0]].set(parts[1], comparison, value) elsif (self[field]) c = Condition.new c.set(field, comparison, value) @subconditions << c else hash_set(field, value) @comparisons[field] = comparison end return self end |
#simplify ⇒ Object
Traverses the tree removing useless conditions.
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# File 'lib/spiderfw/model/condition.rb', line 362 def simplify @subconditions.each{ |sub| sub.simplify } if (hash_empty? && @subconditions.length == 1) self.replace(@subconditions[0]) end @subconditions.uniq! return self end |
#uniq! ⇒ Object
Removes duplicate subcondtions.
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# File 'lib/spiderfw/model/condition.rb', line 341 def uniq! @subconditions.uniq! end |