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author | TP Honey <tphoney@users.noreply.github.com> | 2015-09-08 11:15:45 +0100 |
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committer | TP Honey <tphoney@users.noreply.github.com> | 2015-09-08 11:15:45 +0100 |
commit | 00b11c20c87c028d2206e444c321a8b43d7aa52b (patch) | |
tree | 638a65bda21447740ead495d5209fb4acc3df2d9 | |
parent | 6a1afae97e0451590c833acdd79fd730f49137b9 (diff) | |
parent | 411978db322cefda4e156537491b15dddbf2698f (diff) |
Merge pull request #519 from dmitryilyin/fetch
[MAINT] Improve 'try_get_value' readme
-rw-r--r-- | README.markdown | 51 |
1 files changed, 33 insertions, 18 deletions
diff --git a/README.markdown b/README.markdown index a880222..d345947 100644 --- a/README.markdown +++ b/README.markdown @@ -706,12 +706,18 @@ Converts the argument into bytes, for example "4 kB" becomes "4096". Takes a sin *Type*: rvalue. -Looks up into a complex structure of arrays and hashes and returns a value -or the default value if nothing was found. - -Key can contain slashes to describe path components. The function will go down -the structure and try to extract the required value. - +Looks up into a complex structure of arrays and hashes to extract a value by +its path in the structure. The path is a string of hash keys or array indexes +starting with zero, separated by the path separator character (default "/"). +The function will go down the structure by each path component and will try to +return the value at the end of the path. + +In addition to the required "path" argument the function accepts the default +argument. It will be returned if the path is not correct, no value was found or +a any other error have occurred. And the last argument can set the path +separator character. + +```ruby $data = { 'a' => { 'b' => [ @@ -722,19 +728,28 @@ $data = { } } -$value = try_get_value($data, 'a/b/2', 'not_found', '/') -=> $value = 'b3' - -a -> first hash key -b -> second hash key -2 -> array index starting with 0 - -not_found -> (optional) will be returned if there is no value or the path did not match. Defaults to nil. -/ -> (optional) path delimiter. Defaults to '/'. +$value = try_get_value($data, 'a/b/2') +# $value = 'b3' -In addition to the required "key" argument, "try_get_value" accepts default -argument. It will be returned if no value was found or a path component is -missing. And the fourth argument can set a variable path separator. +# with all possible options +$value = try_get_value($data, 'a/b/2', 'not_found', '/') +# $value = 'b3' + +# using the default value +$value = try_get_value($data, 'a/b/c/d', 'not_found') +# $value = 'not_found' + +# using custom separator +$value = try_get_value($data, 'a|b', [], '|') +# $value = ['b1','b2','b3'] +``` + +1. **$data** The data structure we are working with. +2. **'a/b/2'** The path string. +3. **'not_found'** The default value. It will be returned if nothing is found. + (optional, defaults to *undef*) +4. **'/'** The path separator character. + (optional, defaults to *'/'*) #### `type3x` |