Type (Json function): Difference between revisions
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{{Template:Json:Type subtitle}} | {{Template:Json:Type subtitle}} | ||
This function returns the [[Json class#The_JsonType_enumeration|type]] of a Json object. | |||
This | |||
==Syntax== | ==Syntax== | ||
{{Template:Json:Type syntax}} | {{Template:Json:Type syntax}} | ||
===Syntax terms=== | ===Syntax terms=== | ||
<table class="syntaxTable"> | <table class="syntaxTable"> | ||
<tr><th>%jsonType</th><td><var>JsonType</var> value</td></tr> | <tr><th>%jsonType</th><td><var>JsonType</var> enumeration value of the Json object type. If the Json object is null, the returned value is null.</td></tr> | ||
<tr><th>Json</th> | <tr><th>Json</th> | ||
<td>Json object, which may be <var>Null</var></td></tr> | <td>Json object, which may be <var>Null</var> or any underlying Json object type (boolean, number, string, array, or object).</td></tr> | ||
</table> | </table> | ||
==Usage notes== | ==Usage notes== | ||
<ul> | |||
<li>One would assume the type of a Json object would normally be established as part of the interface between the programs exchanging JSON data. As such, Type might not to be used very frequently. If the source of the JSON data is considered potentially unreliable then, rather than testing Type for each object, one might instead wrap all object references inside a Try/Catch for an [[InvalidJsonType class|InvalidJsonType exception]].</li> | |||
</ul> | |||
==Examples== | ==Examples== | ||
The following example steps through an object and either prints the object string value of the object item (property) or the first item in the item (property) array, if it's an array. The determination of which to do is based on the result of the Type method: | |||
<p class="code">b | |||
%json is object json | |||
%title is string len 64 | |||
%i is float | |||
%json = object | |||
%json("Lee") = "To Kill a Mockingbird" | |||
%json("Faulkner") = array("As I Lay Dying", "Absalom, Absalom", "The Sound and the Fury") | |||
%json("Hurston") = array("Jonah's Gourd Vine", "Their Eyes Were Watching God") | |||
%json("Ellison") = "Invisible Man" | |||
for %i from 1 to %json:count | |||
if %json:itemByNumber(%i):type eq array then | |||
%title = %json:itemByNumber(%i)(1):stringValue | |||
else | |||
%title = %json:itemByNumber(%i):stringValue | |||
end if | |||
printText {%json:nameByNumber(%i)}: {%title} | |||
end for | |||
end | |||
</p> | |||
This prints | |||
<p class="code">Lee: To Kill a Mockingbird | |||
Faulkner: As I Lay Dying | |||
Hurston: Jonah's Gourd Vine | |||
Ellison: Invisible Man | |||
</p> | |||
==See also== | ==See also== | ||
{{Template:Json:Type footer}} | {{Template:Json:Type footer}} | ||
Revision as of 23:19, 18 February 2015
Get type of JSON object (Json class)
[Introduced in Model 204 7.6]
This function returns the type of a Json object.
Syntax
%jsonType = json:Type
Syntax terms
| %jsonType | JsonType enumeration value of the Json object type. If the Json object is null, the returned value is null. |
|---|---|
| Json | Json object, which may be Null or any underlying Json object type (boolean, number, string, array, or object). |
Usage notes
- One would assume the type of a Json object would normally be established as part of the interface between the programs exchanging JSON data. As such, Type might not to be used very frequently. If the source of the JSON data is considered potentially unreliable then, rather than testing Type for each object, one might instead wrap all object references inside a Try/Catch for an InvalidJsonType exception.
Examples
The following example steps through an object and either prints the object string value of the object item (property) or the first item in the item (property) array, if it's an array. The determination of which to do is based on the result of the Type method:
b %json is object json %title is string len 64 %i is float %json = object %json("Lee") = "To Kill a Mockingbird" %json("Faulkner") = array("As I Lay Dying", "Absalom, Absalom", "The Sound and the Fury") %json("Hurston") = array("Jonah's Gourd Vine", "Their Eyes Were Watching God") %json("Ellison") = "Invisible Man" for %i from 1 to %json:count if %json:itemByNumber(%i):type eq array then %title = %json:itemByNumber(%i)(1):stringValue else %title = %json:itemByNumber(%i):stringValue end if printText {%json:nameByNumber(%i)}: {%title} end for end
This prints
Lee: To Kill a Mockingbird Faulkner: As I Lay Dying Hurston: Jonah's Gourd Vine Ellison: Invisible Man